Frequently Asked Questions

View questions frequently asked by purchasers, paver installers, maintainers, homeowners, and designers. To see an answer, click a question below.

Nothing else can match the classic beauty and elegance of a brick home. Building with brick says, "You have arrived." But there's more to brick than just looks. Brick offers lasting value. It can enhance the resale value of your home by as much as 6 percent. Brick is virtually maintenance free. It doesn't rot, dent, or need to be painted and it won't be eaten by termites. Brick is also energy efficient, keeping you cool in the summer and warm in the winter. In short, brick offers you a combination of advantages not found in any other siding material. The world's most beautiful and most practical homes are built with brick.

Single-face fireplace dimensions including the firebox depth, width, and height along with the proportionate flue size are given in Technical Notes 19. The Technical Notes address all the necessary features in a brick fireplace and their relationship to one another.  Details are provided in Technical Notes 19A, while proper chimney construction is outlined in Technical Notes 19B.

Brick costs more than some other commonly used siding materials because brick is a premium product, but it's not nearly as expensive as you might think. In many parts of the country, a new brick home will cost you only a small percentage more than a comparable vinyl-sided home. Other products, such as artificial stucco, cost about the same as brick, but are far less durable and require much greater maintenance and upkeep. 

Brick is a building material that has exceptional "thermal mass " properties. Thermal mass is the ability of a heavy, dense material to store heat and then slowly release it. For you, this means that during the summer months your brick home stays cool during the hottest part of the day. During the winter, brick walls store your home's heat and radiate it back to you. Vinyl, aluminum, wood or EIFS (artificial stucco) are all thin, light building materials that don't have good thermal mass properties. The superior thermal mass qualities of brick have been known for centuries. Most notably, the Pueblo Indians in the Southwest used adobe masonry to moderate weather extremes and keep their homes comfortable. 

A brick home is fire resistant, pest resistant and weather resistant. Brick is such a strong and durable building material that your insurance companies may even offer you a discount on your home insurance costs. Check with your agent for more details. 

Brick is not a one-dimensional product like stucco or siding. Brick allows you to personalize the look of your home with elegant detailing, such as arches and quoins, different bond patterns and special shapes. Brick expresses your personality and style like no other building product can. 

Take a look through this Sunday's real estate section of your local newspaper and read the home listings. Notice how people always list brick as a primary selling point. Brick's beauty and practicality are always a plus when you resell. On average, a brick exterior adds 6% to the resale value of your home.

Brick can be added to an existing home. This can be done by adding a nominal three- or four-inch thick brick in front of the wall and supporting it by either the existing footing or on an angle fastened to the existing concrete or block foundation wall. It is important to properly detail the wall by providing flashing and weep holes at all points of support. The area beneath the angle at or below the ground level should have gravel at least six-inches deep to provide good drainage. The brick should also have at least a one-inch air space between itself and the existing siding. Building paper should cover the existing siding unless it is already provided behind the existing siding. Corrosion-resistant metal anchors should tie the brick to the studs in the existing wall. The joint between the brickwork and all doors and windows should be closed with silicone caulk. Insulation may also be added to increase the total thermal value of the wall. For additional information on installing brick on your existing home, see Technical Notes 28A. Another alternative is to use thin brick in panels and attach them directly to wall studs. This may mean removing the existing siding in order to attach the thin brick. Insulation may also be added if desired. For additional information on installing thin brick, see Technical Notes 28C.

A brick home is virtually maintenance free. Brick is one of the oldest building materials in the world, and one of the reasons it's still so popular is brick's ease of upkeep. Brick never needs painting, never rots, will never be eaten by termites and will never dent or tear. Brick homes built hundreds of years ago still stand today. 

Thin brick can be pried from the wall due to a number of issues. 

If the brown or setting coating is allowed to surface dry, a thin film will form over the coating which prevents adequate bonding of the mortar to the brick. 

Dirt, dust, oil, wax or other debris on the back of the brick may interfere with the bonding of the mortar to the brick. 

If the mortar joint is omitted and the back up is exposed to weathering in the form of freeze thaw, the freezing of water behind the thin brick can apply forces to the brick that pry them off from the wall. Fill mortar joints with a concave tooled joint to protect the backup from moisture. 

Under normal conditions the thin brick may be adequately bonded to the backup, under wind or temperature may create forces in excess of the bond strength which can cause the brick to fall away from the wall. 

Repointing or tuck-pointing existing brickwork may be in order when mortar joints have softened, deteriorated or exhibited pronounced cracking. Generally, repointing involves carefully removing existing damaged mortar while not disturbing or cutting the existing brick. The joint is then repacked with mortar in layers. It is important to remember that the mortar should always have slightly less strength than the brick. Usually, the best mortar for use in repointing is what was in the wall to begin with. For most walls less than 70 years old, generally Type N or O mortar should be used when repointing. For structures older than this, it is best to try and determine what the original mortar consisted of and match that. For more information concerning repointing, see Technical Notes 7F. 

A brick wall may be painted provided the correct preparation is done, the proper paint is selected, and the paint is applied correctly. Generally, new brick walls are not painted. However, if it is desired to paint a recently constructed brick wall, the wall should be allowed to fully cure 28 days and should not be cleaned or treated with acid solutions. Alkali-resistant paints should be used and a zinc chloride or zinc sulfate solution may need to be applied to the wall to neutralize the surface. Painting brick does not preclude good construction and detailing practices. Any deficiencies such as surface deposits; broken brick; cracked, loose or missing mortar; or inadequate flashing and weep holes should be corrected prior to painting. In addition, the brick should be thoroughly cleaned and given ample time to dry before application of paint. See Technical Notes 7F and 20 for more information. For brickwork to function properly, the wall must resist moisture penetration and be permeable to vapor from the structure. Consequently, any paint applied to the wall must also have these same characteristics. In addition, the inherent features of a brick wall which channel water out, such as weep holes and vents, must not be clogged by paint or caulk to inhibit the flow of water. Latex and portland cement-based paints perform well on brick walls. Oil-based, alkyd, rubber and epoxy paints do not allow any vapor in the wall to escape and consequently should not be applied to brick. Prior to painting, the brick should receive a prime coat suitable for the paint application per manufacturer's instructions. For additional information on painting brick masonry, see Technical Notes 6.

Generally, water repellents are only an interim solution to any water penetrating a brick wall since they loose their ability to repel water after 1 to 10 years. However, in cases where all other options have been exhausted, it may be considered as long as one is aware of the inherent nature of water repellents. There are basically two types of water repellents: films and penetrants. Films such as acrylics, stearates, mineral gum waxes, urethanes and silicone resins form a thin membrane over the brick. Penetrants such as silanes, siloxanes and blends actually penetrate the brick surface. Films are good at repelling water but poor at permitting water vapor transmission which allow the wall to breathe. Penetrants, on the other hand, are good at both. They will usually have a matte finish while films may produce a higher sheen. Penetrants are more acceptable since they allow any water present in the brick to exit the wall. However, penetrants will not provide graffiti-resistance to a wall while some films will. Application of a water repellent does not negate proper brick construction and detailing procedures. Any deficiencies in a brick wall such as inadequate flashing, weep holes, mortar joints or broken brick should be corrected prior to the application of a water repellent. The wall should also be cleaned and allowed to thoroughly dry before administering a water repellent. For additional information on water repellents, see Technical Notes 6A.

ASTM C 67 contains a freezing and thawing test which is presently the industry accepted standard. This test should be conducted prior to delivery of brick to the job site. Bricks pass the test if, after 50 freeze/thaw cycles, they do not exhibit significant weight loss, breaking, or cracking. The test is designed to be performed on brick that have not yet been built into a wall.

There are many factors that contribute to brickwork's ability to withstand cyclical freeze/thaw including workmanship; the mortar type, its air content and consistency when laid; and the degree of saturation in a wall. These factors cannot be tested for in ASTM C 67 since they involve other elements outside the brick itself. 

Well, the brick is very highly resistant and does not needs to be painted very often. 

Cleaning is much easier if care is taken during application to avoid smearing mortar on the faces of the thin brick. Special grout release chemicals may be applied to the brick before the joints are filled to make cleaning easier. 

Water may be used to remove much of the adhesive and mortar before they have set. Remove cementitious mortars according to recommended cleaning procedures for thin brick. Procedures vary due to color and texture' Remove other mortars according to manufacturer's instructions. Remove dried adhesive according to the adhesive manufacturer's instructions. Do not saturate the surface or smear. Never use muriatic acid, wire brushes or other abrasive methods to clean thin brick. 

As always, the wall should be thoroughly saturated with water before and after any cleaning application. Also, a small inconspicuous area of wall should be tested to confirm that any solutions used will not harm the brick. Freshly applied paint can be removed with a solution of trisodium phosphate mixed with water at a rate of 2 lb. per gallon of water. Apply the solution to the brick; allow it to soften paint; and remove with scraper and stiff bristle brush. Proprietary chemical compounds are also available through local distributors to remove fresh paint. Existing paint which has been in place for some time is more difficult to remove and may require using abrasive techniques with non-steel scrapers or sandblasting by a professional. Certain brick should not be sandblasted. Proprietary chemical compounds from local distributors in the form of a gel solvent may be necessary to soften existing paint. Numerous applications may be necessary depending on the number of paint layers. For additional information on removing paint from brickwork, see Technical Notes 20.

Most stains and discoloration can be removed from brickwork if the proper cleaning technique is employed. There are essentially two categories of stains; those which are externally applied to the wall and those which originate from within the wall. Those which come from within a wall may need additional investigation to prevent the stain from returning. As always, it is important to thoroughly saturate a brick wall before application of any cleaning solution. As a general rule, acidic cleaning solutions should only be applied to red brick with no surface finish such as sand. Also, an inconspicuous area of the wall should be tested with any cleaning solution for compatibility prior to application on the entire wall. Any cleaning solutions should be thoroughly rinsed from the wall. Most stains can be dealt with by thoroughly washing the wall with a common household or kitchen cleanser dissolved in water and applied to the wall with a stiff bristle brush. If this is ineffective, a poultice which dissolves the stain and pulls it into an inert material may be necessary. The inert material can be talc, whiting or fuller's earth while the solvent will vary based on the type of stain. Proprietary cleaning agents can also be employed to remove specific stains. Sandblasting and pressure washing brickwork can also be options for certain brick when especially stubborn mortar or externally applied stains are involved. Bricks with coatings such as sand or slurry finishes should not be cleaned in this manner. Sandblasting and pressure washing should usually only be undertaken by a competent professional with experience. If improperly executed, either of these methods can permanently damage the brick. For more information on stain removal, see Technical Notes 20.

To answer this question, you need to understand the consequences of leaving or removing plant growth. This growth on brick can potentially damage it by forcing root tendrils into the mortar joints. Moisture can then find its way into the wall and freeze-thaw action or other moisture related events can occur resulting in damage. However, ivy also sheds rainwater and reduces the surface temperature of the wall. Properly constructed walls with good workmanship and well-tooled joints can also resist tendril intrusion better than poorly constructed walls. 

When existing plant growth is removed from a brick wall, it may also remove part of the mortar from the joint. This could result in the wall having to be repointed by removing any broken mortar and repacking with new. Further, complete removal of the tendrils is difficult. Failure to do so may result in stains on the wall. 

Therefore, it is an evaluation which is best made by the owners taking these as well as the aesthetic and economic considerations into account. While plant growth can shorten the life of brickwork, a well-constructed wall should still last for many decades. 

Additional information on plant growth on brickwork is available by ordering Engineering and Research Digest #621 from the Brick Bookstore

A brick's color can be attributed to its clay composition, any added compounds, its firing temperature and any surface treatments. Because brick is composed of naturally occurring materials, all brick will not necessarily be exactly the same. For this reason, some brick may be of a slightly different color than others in a given batch. Usually, this adds character to a wall, but occasionally it is desired to blend these brick with other brick in the wall. This can be done by individually staining the brick in question.

Staining is a common practice and is usually done by a professional with expertise in its application. The stain itself is a proprietary product made specifically for brick. A local brick supplier in your Yellow Pages should be consulted for a product and professional applicator. Since the surrounding mortar joints must be masked, it is a time consuming process and is usually only done when a limited number of brick are involved. If staining is done properly, it should have no detrimental effect on the bricks and should provide a long lasting finish. 

A flexible base consists of compacted crushed stone, gravel or coarse sand. Only mortarless brick paving is suitable for this type of base. A semi-rigid base consists of asphalt concrete, commonly referred to as asphalt. Once again, only mortarless brick paving is suitable over this type of base. A rigid base is defined as a reinforced or unreinforced concrete slab on grade. Mortarless or mortared brick paving may be placed over this type of base.

Flexible bases include crushed stone, gravel or coarse sand. Applications for flexible bases range from residential patios to city streets. Flexible paving systems are typically the most economical to install since less labor and fewer materials are involved. A flexible paving system allows easier repairs to utilities located beneath the pavement. Flexible pavements also allow for water to percolate down through the system instead of running off on the surface. The thickness of each layer in a flexible pavement depends upon the imposed loads and the properties of each layer. A pavement subjected to heavy vehicular traffic requires a thicker base than a pavement subjected to pedestrian traffic. 

Mortared brick paving can be used for any type of pedestrian or vehicular traffic in both interior and exterior applications. This type of assembly is especially well-suited for heavy vehicular areas such as streets or parking lots and where surface drainage is necessary. 

The standard brick size is a 4 x 8 paving brick. We call this a True paver because the actual dimension is 4in.x 8in. It takes 4.5 brick to cover one square foot of area. Take the total area of desired patio space and multiply it by 4.5 to get the total number of brick needed. Most installers assume that an additional 5% should be added to cover waste. The web calculator will provide this information. The calculator can break up the paving area into rectangular sections. A maximum of 8 sections are allowed. If you have more sections that 8, try running the calculator multiple times as required and add the quantities by hand. Refer to patio calculator on the web. 

Please refer to our online technical documentation. Refer also to FAQ's 29, 30 and 31.

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Note:

  • 29 = How can I match existing brick? [NID-957]
  • 30 = What type of base should I use for brick paving? [NID-950]
  • 31 = Can brick pavers be installed over an existing concrete or asphalt driveway, patio or walk?  [NID-959]

Brick paving can be installed over existing concrete or asphalt as long as it is in reasonably good shape. To ensure an adequate foundation for the brick, the existing concrete slab or asphalt should be inspected and repaired as necessary. Any cracks, chips, holes, ruts or spalls should be repaired in order to achieve a flat surface. The brick can be installed either with or without mortar. If no mortar is used, a half-inch setting bed of coarse sand should be laid and compacted. An edging of metal or heavy-duty plastic should be placed around the perimeter of the brickwork and set to just below the height of the finished brick surface. Pavers can then be placed in the desired pattern on top of the sand. The bricks should be placed as close to each other as possible. It may be necessary to cut some of the brick near the edging. Once the brick are all in place, install mason's sand between the brick and over the surface. Sweep away excess surface sand and the brick pavement is ready for traffic. If mortar is used, the concrete slab should be prepared in the same manner as above. A half-inch mortar setting bed should then be applied upon which the bricks are set with mortar placed between the pavers. Only a small area should receive the setting bed at a time in order to ensure that it does not set prior to laying the brick. Mortared brickwork should not be laid on asphalt. For additional information on installing pavers, see Technical Notes 14 and 14A. An online course, "Paving Training Program: Clay Pavers" is also available.

A new brick pavement can be constructed on asphalt, concrete, or compacted gravel as a base. For asphalt and concrete bases, the base material should be installed according to standard construction procedure and then the brick can be constructed on top. (See previous question.) For a compacted aggregate base, the earth below should be well compacted. All brick pavements should have the earth graded to a minimum slope of a quarter-inch per foot for drainage. Then four-inches of crushed stone, followed by a layer of geotextile material, if desired, and one inch sand setting bed of coarse concrete sand is laid. An edging of heavy plastic or metal should be installed at the perimeter of the brick. The brick should then be laid on top of the sand and cut as needed at the edging. Mason's sand should then be spread on the top and in between the brick and consolidated with a plate compactor if necessary. Mason's sand should be added until all the joints are filled and any excess sand should be removed. For pavements such as driveways, a six to eight-inch gravel base should be installed and compacted with a plate compactor. Then a geotextile material should be installed and a one-inch setting bed of coarse sand laid. Placing edging, brick and mason's sand between the joints should then proceed as outlined above. Heavier duty pavements can be laid in the same manner, but the base is thicker. Adequate preparation of the earth before installation and compaction of the entire assembly after installation with a plate compactor are essential to a well-constructed brick pavement. For additional information on installing brick pavements, see Technical Notes 14 and 14A. An online course, "Paving Training Program: Clay Pavers" is also available.

The number of brick per square foot is determined by computing the face height with a mortar joint and length of a brick with a full mortar joint on one end - in inches. Divide this area into 144 (the number of square inches in a square foot). This is the number of brick per square foot. This value is shown on the web page for each size. 

Only Interstate Brick company manufactures the Atlas™ structural brick. These are a brick that can be reinforced and grouted and range in size from 4x4x12 to 8x8x16 inches (width x height x length). 

Larger units are installed more quickly, and have fewer mortar joints, than smaller brick. While larger units can create a distinctive language of their own (and provide a more unique scale to the wall elevation), Emperors, Super Emperors and Atlas units can also be slotted to duplicate the look or pattern of smaller brick. Schedules can be reduced, labor is saved, and moisture resistance is increased due to fewer mortar joints. Experience for yourself the creative possibilities of Interstate Brick. Download Masonry Designer

The number of brick required is based on the actual size of the brick. The larger the brick the fewer number of brick required. Add up the total surface area of the wall. Subtract out windows and doors and throw in a value for waste. Most installers assume that an additional 5% should be added to cover waste. The web calculator will provide this information. The calculator can break up the wall area into rectangular sections. A maximum of 8 sections are allowed. If you have more sections that 8, try running the calculator multiple times as required and add the quantities by hand. Refer to wall calculator on the web. 

A typical semi truck will haul approximately 12,500 modular brick. A 50 ft. box car will typically haul 43,000 modular brick. This equates to approximately 48,000 lbs. on a truck and 150,000 lbs. on a 50 ft. rail car. If you are not shipping modular brick, determine the weight of the individual brick and divide this into the allowed weight of the carrier. Add a variant factor of 5% and this is the approximate weight. Contact the company freight department for actual number of a specific brick on a rail or truck.

Atlas™ structural brick are the most economical brick used in any clay wall system. Atlas™ serves as form, finish, and functions in one material and is installed by a single trade in one sequence. When used as a single wythe (or modified single wythe) wall system, Atlas™ can often eliminate structural steel required to carry roof loads and can eliminate the need for painters, framers, and other finishes. By reinforcing the Atlas™ wall, the requirements of a complex backup system are also eliminated. 

Yes, Interstate has a number of colors considered stock in a wide variety of sizes from Modular to Atlas Structural Brick. Stock colors vary from year to year based on what colors and sizes are selling in the largest quantities. Contact Interstate for stock colors. Only Interstate makes the Atlas brick 

Total wall costs are comprised of both labor and material. While material costs for brick are nearly identical in any size, labor costs are a function of time. RS Means (a national estimating service) indicates that labor makes up about 70% of the total wall cost for a modular brick veneer. Because the larger Emperor™ brick can double the total square footage installed per mason each day, labor costs can be halved and total overall costs are reduced by approximately 25-30%. Additionally, equipment costs, interim financing costs, and numerous other advantages can be realized. 

Interstate Brick sells direct in Utah and markets through Distributors and Dealers located through out the rest of the United States and Canada.

Designers (40)

Control Joints are intended to create artificial planes of weakness where stresses in the wall can form their own cracks, breaks, or fissures and at the location of the control joint. 

Atlas™ brick are not normally tested in the same manner as concrete block (CMU). Because of the lower compressive strength of the material, CMU can be tested in a 16" length using testing machines with capacities of 250,000 lb. ratings. Structural brick have unit strengths 4 to 5 times that of concrete block and therefore must be cut into smaller rectangular sections. This is done by cutting the unit in half and removing the 'dog ears' flush with the web to create a rectangular unit. Prisms are also done in the same manner. Testing machines must be rated in excess of 450,000 lb. capacity in order to break the brick within the elastic range of the testing machine. Machines with ratings lower than this may cause premature failure.

The testing machine must also have a spherically seated head that adjusts for slight distortions in the material. A gypsum capping compound is used to cap the units and the prisms to also level out any non-uniformity in the units. 

Unlike concrete products, fired clay brick colors do not fade. Color changes over the years are a result of atmospheric conditions. Soot, dirt, and grime all of which can be cleaned by remedial cleaners. 

There are two primary reasons steel stud parapets are advised against. The increased possibility of water penetration and resulting corrosion is one issue. A parapet is externally exposed on three sides making it one of the most vulnerable areas of a building. Furthermore, it is insulated differently than the wall below and can potentially be subjected to more thermal-related issues than other parts of a wall. Water penetration is also more likely due to rain or condensation. This water penetration could lead to corrosion and other future problems.

The second issue deals with the differential movement of the brick and steel stud. The stud can expand at a much higher rate than the brick. This could effect the coping used on the top of the wall and surrounding mortar joints. 

Obviously, these issues can be dealt with in design and construction, but BIA has seen some problems in the past with this type of assembly. 

If you have browsed our FAQ's and cannot find what you are looking for, please feel free to CONTACT US and we will answer your question as quickly as possible.

Visit a brick showroom near you to review your options. You'll have the chance to review hundreds of brick and mortar combinations. To locate a showroom, go to the online Member Directory. Also, be sure to check your local Yellow Pages under "Brick." hundreds of brick and mortar combinations. 

The thin set method omits the moisture barrier, wire mesh, and the scratch coat and only uses the setting mortar or bond coat to the brick. Use the thin-set method on interior surfaces only. 

Brick is the smallest dimension it will be in its long service life when it leaves the kiln. As it is exposed to moisture from a variety of sources including the air, wet mortar, rain and condensation, it will naturally expand since it is a clay product. Temperature will also cause brick to expand and contract. Consequently, it is important to incorporate expansion joints into brickwork to accommodate this movement. Expansion joints should be located where stresses or cracks are likely to develop in brickwork. Prime candidates for expansion joints include long expanses of walls, corners, offsets, setbacks, and parapets. Expansion joints should also be located below shelf angles to account for vertical expansion of brick. When accent bands of other materials such as precast or concrete masonry units are included in a wall, it may be prudent to include a bond break or slip joint between the two dissimilar materials if their coefficients of expansion are significantly different. Bond breaks are created by embedding a smooth sheet such as flashing materials in the mortar bed which allow the materials to move independent of each other. When determining where expansion joints should be placed, it may be necessary to calculate the amount of expansion anticipated. This can be done by knowing the coefficients of expansion of the brickwork and the parameters of its environment. For additional information on expansion joints, see Technical Notes 18 and 18A.

Certain brick colors have integral minerals that may be negatively effected by the cleaning process. Interstate has put together some general recommendations in our Technical Bulletin. Additional information can be retrieved from the BIA Technical Notes 20.

Interstate Brick manufactures a wide variety of shapes which provide architectural details not obtainable by saw cutting standard size brick. The least expensive shapes are extruded. Some shapes are hand formed and are much more expensive. If you do not see a shape on this web site, contact the manufacturer for available options. Link to shapes area of web. 

When structural brick are used, reinforcing in the brick work against the expansion of the brick to post-tension the reinforcing. This reinforcing also is used to transfer the bricks tension into the reinforcing. Spacing of expansion joints can be spaced at greater differences than those for brick veneer. Horizontally reinforced structural brick have performed well with expansion joints at 60 ft. centers. To prevent cracking at corners, continuous reinforcing should be used. Contact the manufacturer for specific recommendations. 

Since the primary ingredient in brick is clay which is fired to around 20008 F, it is a non-combustible material. As such, it is an excellent cladding choice to resist or confine fires. A brick wall's fire resistance rating can be calculated. This is done by extrapolating from known fire resistance periods for a given thickness of wall. Refer to Technical Notes 16B for further information on how to calculate fire resistance ratings for specific brick walls. Currently, there are four Underwriters Laboratories tests which have assigned fire resistant ratings to specific wall assemblies. They include U302, U418, U425 and U902. U302 yields a 2 hour rating and involves a brick veneer drainage wall with wood studs and gypsum sheathing and wallboard. U418 and U425 vary in rating between æ to 2 hours and are brick veneer drainage walls with steel studs and gypsum sheathing and wallboard. U902 consists of a drainage wall with brick veneer and concrete masonry units and has a 4 hour rating. For further information on fire resistance of brick, see Technical Notes 16.

The Quartette is an Atlas™ brick. Frequently a designer wants to scale down the visual appearance of the brick. In this case a slot is placed in the middle of the brick. To achieve a running bond pattern the brick must be laid in quarter or 3/4 bond. To allow the reinforcing to align, the coring must be modified and a starter unit is required at the corners. Quartette flier. 

Thin brick is unlike regular facing brick when it comes to expansion joints. Because of the thickness of the material, the substrate plays a bigger role in the movement of the wall. As most substrates and adhesion materials are concrete products, the primary movement of the substrate is shrinkage. Crack control is placed at the spacings and detail as required for stucco. 

A control joint in stucco is intended to relieve stress and limit or control the cracking in the membrane of the stucco only. Usually installed at a maximum of 144 square feet. It is not necessary and in fact can be detrimental to cut the lath behind the control joints. A control joint will not stop stucco from cracking if the stresses imposed upon the stucco membrane are greater than can be dissipated by the stucco and/or the control joint. 

ASTM C1063 requires that panel areas are no larger than 144 square feet. In addition, the maximum spacing of control joints should be less than 18 ft. The aspect ratio of the panel should also be held to a maximum length to width ratio of 2 1/2 to 1. 

An expansion joint in stucco is a two-piece slip joint that is installed at a similar expansion joint in the structure of building. When installing an expansion joint, the framing, sheathing and lath should be cut to create a true plane of expansion. Consult a stucco representative for proper placing of control joints. 

Weep systems in use include wicks, oiled rods, weep tubes, open head joints, and vents. BIA does not advocate one type of weep system over another. Wicks should be spaced at 16" o.c. with the remainder of the weep systems spaced at 12" o.c. Rope wicks can be made from cotton sash cord. Drainage materials used at the bottom of the cavity are most effective for open type of weep holes like open head joints, weep tubes, etc., however it could be used with rope wicks. It is important to maintain a clean, open cavity for weep holes to function properly. If mortar droppings are anticipated, then it is best to detail a drainage material that will catch any mortar like pea gravel or mesh. For additional information on weep holes, see Technical Notes 7.

A flashing material must be impervious to water, tough enough to withstand construction abuse and yet flexible enough to conform to the desired shape, and not deteriorate while in service. It should also not react with mortar or corrode and should be compatible with joint sealants. Traditionally, copper sheet has been used as flashing in masonry walls. Stainless and galvanized steel sheet have also been used as flashing. More recently, plastics and combination flashings have found their way into masonry walls. While there are pros and cons to each type of flashing and a range of cost associated with each, they will all perform satisfactorily as long as they meet the basic criteria for a flashing material. For additional information on flashing, see Technical Notes 7A.

The standard size for a brick is normally considered to be the modular brick which is 3.625 wide x 2.25 high x 7.625 long. Call out brick using width x height x length. 

Atlas™ structural brick is a hollow clay brick product that was developed to permit the use of reinforcing to enhance the structural characteristics of brick. Brick is an excellent product to resist compression loads, but often masonry is required to act as a beam or wall to resist earthquake, wind or gravity loads. Reinforcing steel placed in the brick cells is grouted to create resistance to tension. Atlas brick are designed similar to Concrete block but with allowable design stresses 2 to 3 times stronger. For further information on Atlas structural brick see Atlas technical data brochure. 

Curtain wall is a term often associated with glass window framing. With glass, it is commonly understood that the glass has no ability to carry building loads. Wind, earthquake and thermal loads are transferred from the glass to mullions and girts. The brick curtain wall behaves in a similar manner. 

In the brick curtainwall, the brick are supported on the foundation and run past the floors with attachments at the floor which isolate the vertical deflection of the building from the wall. This concept eliminates the need for perimeter floor beams that are designed to carry the vertical load of the brick. The tallest building known to the author is 180 feet. The exterior brick wall is a continuous 180 feet tall, horizontally and vertically reinforced with no ledger angles. For more information see Crittendon. 

The temperatures of the air and the materials - thin brick, adhesive, and the surface to which the thin brick will be applied - must be between 45 degrees F and 90 degrees Fahrenheit. This temperature range must be maintained for 48 hours after the application has been completed. 

Both exterior and interior walls must be rigid (stiff). The maximum variation from plane is 1/8" in 8'0". In Enterior work, vertical and horizontal control joints must be installed every 18 feet or more frequently - not to exceed 144 square feet between control joints.

Expansion joints are placed in brick to allow the cumulative expansion to combine at the expansion joint causing a compression of the joint. Expansion joints are filled with a 50% compressible neoprene material. Expansion joints are generally spaced to accommodate twice the design expansion to allow for the expansion joint material. The expansion joint is typically between 3/8" to 1/2" thickness. 

ASTM C 67 has a method to test for efflorescence, but it is meant to be conducted before the brick are shipped to the job. While it will not result in a quantitative amount of efflorescence present, it will indicate if the brick effloresces or not. Unfortunately, this test is not appropriate for brick that have already been built into a wall. Chemical tests on existing efflorescence could be done to find the type of salt present. A masonry consultant should be contacted to make this determination. For additional information on efflorescence, see Technical Notes 23 and 23A.

BIA publishes a series entitled Technical Notes which contains our most current information available on brick. This series covers a broad range of topics including design, specifications, properties, and construction. The Technical Notes present the most up-to-date information available on brick from BIA staff engineers. Most of the topics and answers given in this Frequently Asked Questions feature are derived from the Technical Notes.

Atlas™ structural brick has a compressive strength of masonry f'm of 3000 psi or more depending on the color. The darker the color generally the stronger the brick. This value is compared to a typical design value of 1500 psi for Concrete block masonry. This means that a thinner brick wall can generally carry the same load as a thicker concrete block wall which saves building space and cost. 

Atlas™ structural brick has a compressive strength of masonry f'm of 3000 psi or more depending on the color. The darker the color generally the stronger the brick. This value is compared to a typical design value of 1500 psi for Concrete block masonry. This means that a thinner brick wall can generally carry the same load as a thicker concrete block wall which saves building space and cost. 

The number of brick required per square foot is based on the size of the brick. The larger the brick the fewer the brick required. To determine the number for a wall area, measure the area (Height x Length) of the wall to be covered. To determine how many- thin brick are needed multiply the wall area by the number of brick per square foot. For example: If the height of the wall is 10 feet and its length is 20 feet, the area of the wall is 200 square feet. About seven modular thin brick are needed to cover a square foot, so 200 square feet X 7 thin brick per square foot = 1,400 thin brick to cover the wall. Remember, there will be some losses because of cutting and damage, so order extra thin brick (most installers assume 5% waste). 

The color of a brick is determined by a variety of factors: the blend of clays, the temperature it is fired at, pigments such as Manganese and Chromite, and sometimes slurry coatings poured onto the brick before firing. Flashing is also a firing technique used to alter the color by reducing Oxygen which causes incomplete combustion in the kiln causing a darker shade to the brick.

Thin brick can be treated with water repellents in the same way they are applied to full thickness veneer brick. See Interstate Technical bulletin for recommendations. 

Atlas™ brick have special coring called cells that allow them to be reinforced and grouted as required by design. Those cells that are not grouted can be insulated using foam beads, Styrofoam inserts, and poured in expanded insulation. See the Atlas™ Technical Data Brochure for insulative values for various insulations. 

The model energy code requires an R-value of 5.7 for masonry walls for schools, offices and other buildings. When greater resistance to heat loss is desired, an integral pilaster design which consists of two wythes of brick separated by an air space with rigid insulation filling the  air space. This gives a rigid surface on both the exterior and interior wall. When a soft wall (drywall) is desired, rigid insulation is placed on the back of the brick and light gage framing studs are placed behind that to support the drywall. Flashing runs through the brick to the back side of the insulation and up the back of the insulation. Use closed cell extruded polystyrene insulation. 

Use over clean, sound, dimensionally stable masonry or concrete. If the walls are wet, the water source must be discovered and eliminated. Painted concrete should be brush hammered or heavily sand-blasted. Concrete and masonry surfaces should not vary more than 1 /4" in 8 feet. 

Expansion and control joints in a masonry or concrete substrate must be mirrored in the thin brick. If a metal lath is used, it must be cut at the expansion joint. Mere the thin brick system meets other materials, flashings must be installed to direct the flow of water clown and out. Do not rely on caulking. 

It is good practice to install a wire lath. Use galvanized or stainless steel wire lath for all exterior applications. 

Apply the scratch coat of mortar on top of the wire lath, masonry or concrete. Float surface of the scratch coat plumb and true and allow to set until firm. 

Apply the setting coat with the straight edge of the trowel, and then the notched edge of the trowel should be used to groove the coat just prior to installation of the thin brick. Then use the notched edge of the trowel to groove the setting coat just prior to installation of the brick. 

Backbutter or apply a setting coat to the back of the brick. 

Space thin brick 3/8" apart. Beat the brick firmly into position with a beating block or rubber mallet. All edges must be sealed with mortar so that there are no voids between the brick and the wall. 

Joints must be free of dirt, debris or spacers. Sponge or wipe dust and dirt from thin brick faces. Press the mortar into joints with a tuck-pointing tool so that they are full and free of pits and voids. Tool joints when recommended by mortar manufacturer. Use a masonry joint tool, screwdriver or other suitable implement. Keep the jointing tool clean and damp.

Install gypsum wallboard or concrete board to the exterior face of the studs 

Install a water resistant membrane on top of the wallboard. Lap and seal joints according to the manufacturer's instructions. Because the thin brick system forms the weather barrier for the structure in exterior applications, proper application of the water resistant membrane is mandatory. 

Install a wire lath over the water resistant membrane. Use galvanized or stainless steel wire lath for all exterior applications. In exterior applications, where the thin brick system meets other materials flashings must be installed to direct the flow of water down and out. Do not rely on caulking. 

Apply the scratch coat of mortar on top of the waterproof membrane and metal lath. Float surface of scratch coat plumb and true and allow to set until firm. 

Apply the setting or brown coat with the straight edge of the trowel, and then the notched edge of the trowel should be used to groove the coat just prior to installation of the thin brick. 

Backbutter or apply a setting coat to the back of the brick. 

Space thin brick 3/8" apart. Beat the brick Firmly into position with a beating block or rubber mallet. All edges must be sealed with mortar so that there are no voids between the brick and the wall. 

Joints must be free of dirt, debris or spacers. Sponge or wipe dust and dirt from thin brick faces. Press the mortar into joints with a tuck-pointing tool so that they are full and free of pits and voids. Tool joints when recommended by mortar manufacturer. Use a masonry joint tool, screwdriver or other suitable implement. Keep the jointing tool clean and damp. 

The need to control moisture is dependent on the location of the project. In humid climates the flow of moisture moves toward the interior as a higher humidity exterior moves water to low humidity interiors. In low humidity exteriors and high humidity interiors the flow is to the exterior. Couple this with environmental concerns such as rain or snow and the issues are complex. Because of this, it is important to involve a mechanical engineer to assess the dynamics of the wall system. 

In low rainfall climates, single wythe applications may behave without any problems. In high rainfall climates, the Atlas™ wall may require a drainage system consisting of vapor barriers and flashing. Contact your Interstate representative for more information. 

Unfortunately, there is no national database of brick colors and textures. However, a local brick distributor representing a wide variety of manufacturers will probably be able to match your brick if it is still manufactured. A good brick salesman will know which brick in his stock comes closest to yours. This web site also has links to manufacturers many of whom have brick displayed on their web site. For names of local brick manufacturers and distributors, see your local Yellow Pages under "Brick". 

The reason concrete block cracks is primarily due to the fact that concrete shrinks when it dries and expands when it gets wet. If you consider the dynamics of concrete, water is added to concrete in forming the block units upon curing or hydrating, the block shrinks. When the block are placed in the wall, water is added to the mortar which transfers to the block while they are wet which causes additional expansion. Grout may also be added to the concrete block which also causes expansion. This compresses the mortar joints while they are wet. From this point the wall begins to dry and as it does it shrinks. As the block shrinks, it pulls away from the surrounding materials which are also block. As these units dry together, the cumulative shrinkage creates forces in the block which exceed its internal tensile strength capabilities. Once this happens the units crack. Control joints are placed in the block at intervals of 30 ft. or less in an effort to keep the stresses localized forcing the crack at the control joint. Atlas™ brick on the other hand begin expanding as they exit the kiln. This is the smallest the brick is during its life. Brick are comprised of clays and with moisture these clays expand. Some shrinkage occurs with cold temperatures, but the predominant direction of movement is expansion. Instead of pulling itself apart as in the case of concrete block, the brick push on surrounding brick compressing all of the mortar joints making them more water tight. Cracking generally occurs at corners where the long wall tries to push the attached adjacent wall bending the corner and forcing tension at the corner which causes a crack if reinforcing isn't placed in the brick to take the tension. Expansion joints are placed in the wall to help prevent this cracking. See FAQ: " What are expansion joints?" for more information on this subject. For this and other reasons brick walls are more water tight than concrete.

In some brick, the color of the brick is defined by adding a pigment to the clays before firing. Other times a coating is poured onto the face and sides of the brick. In addition, the temperature of the kiln and the combustion in the kiln will create other colors. With many brick a change in firing temperature of 50 degrees will change the color of the brick. Brick are generally fired between 1900 and 2100 degrees Fahrenheit. 

Because of the shrinkage associated with clay during the drying process, we have not been successful at making a solid bond beam unit. These are most commonly placed as lintels for windows, doors and other openings. Instead, Interstate suggests using soldier courses at the lintel location. (See page 14 of the Atlas Technical Data Brochure under Special Reinforcing).

Homes have been built for hundreds of years with the knowledge that brickwork is not impervious to water. Water can migrate into brickwork. Brickwork handles this moisture by either having a cavity or separation between itself and the wall behind it or by being so thick that it acts as a barrier to the water. For a drainage wall, water travels down the backside of the brick in the air space and is then channeled out with flashing (metal or plastic sheet) sloped toward the face of the wall and weep holes (small openings or tubes) spaced every few brick at the mortar joints. These flashing and weep holes should be located above all doors and windows, below all window sills, and above the ground at the base of the wall. In a barrier wall, the mass of the brickwork keeps the interior of the wall dry by allowing water to evaporate before proceeding all the way through the wall. Only under prolonged exposure to sustained moisture or rain will a barrier wall exhibit moisture on the interior. When this occurs, the moisture then drains down the back of the wall into flashing at the base which channels it out through weep holes. The overwhelming majority of brickwork is properly detailed and constructed, experiencing no moisture problems. In the few instances where moisture is a problem, it can be attributed to poor construction or detailing in the brickwork. It is important to maintain a clean space behind the brick in drainage walls. Full contact between mortar and bricks and proper installation of flashing and weep holes are also important to ensure the highest water penetration resistance. Applying and maintaining a proper sealant around window and door openings also plays a vital role in keeping moisture out. For additional information on water penetration resistance of brick, see Technical Notes 7, 7A and 7B. For additional information on cleaning, see Technical Notes 20.

Atlas™ brick and Concrete block can be used together so long as both material properties are considered. Because Concrete block is a cementitious product and shrinks upon drying, control joints should be placed in the walls to accommodate the block shrinkage. The Atlas™ brick's primary movement is expansion which acts as a restraining element against the block. This restraint may create greater tension forces in the block which could cause shrinkage cracks to occur at more frequent spacing. 

Because Atlas™ are 2 to 3 times stronger than block, use block design stresses when combining both materials. Because of this, Atlas™ can replace a CMU building with little changes. Contact the manufacturer for suggested considerations. 

Brick is an all-natural building material that is made from a mix of clay and water that is then baked, or "fired," in a kiln until hardened. Different clays produce different colors, and there are many different types of clays. In addition, various natural coatings, such as sand and limestone, can also be added during the firing process to produce different colors, effects, textures and finishes. Even a brick's position in the kiln can affect the final look. When you combine these with the tonal varieties of today's mortars, you can see that your color choices in brick are virtually endless.