Technical Services Digests

Short, informative documents covering many common brick and masonry issues are available here for free download. Builders, engineers, and architects who require additional help are welcome to contact one of Acme Brick Company's regional engineers through their local Acme Brick sales location.

TSD 088

 Mortar Properties Comparisons for Masonry Cement, Portland Cement/Lime, and Hill Country Mortar Mix

Dr. John H. Matthys has conducted extensive research to compare masonry cement mortar performance with Portland cement lime mortars. An additional research project compared Hill Country Mortar to the previously tested masonry cement and Portland cement and lime mortar.

TSD 162

Face Cracks and Dryer Cracks in Brick

Dryer cracks or face cracks are normal in many brick blends and are a part of the distressed image of rusticated brick. They occur after brick are formed during the drying process and before they are fired. Dryer cracks are typically vertical and do not extend all the way through the brick. Document addresses common questions to help you better understand these occasional cracks when you see them.

TSD 180

Lime and Manganese Pops on Brick

Lime is a naturally occurring material in some clay deposits. Some fine particles of lime occasionally get into the clay body. Small pieces of limestone within the clay may turn to quicklime, if they do not fully dissolve in the clay during firing. If these particles are near the face of the brick and come in contact with moisture, they can expand and exert enough pressure to break small chips off the surface of the brick. We call these chips “lime pops,” and they usually occur within the first year after brick are made.

Manganese is also is present in some clay deposits. As with limestone, small pieces of manganese oxides may remain after firing. If they are near the face of the brick and come in contact with moisture, they can also expand and break small chips off the surface of the brick. We call these chips “manganese pops,” and they also typically occur within the first year after brick are made.

TSD 204

Cracking of masonry veneer around wood columns

Document addresses three main issues:

  • why cracks occur;
  • how much does wood expand; and
  • how to prevent cracks.

TSD 206

Minimum Size of Cut Brick at Door or Window Jamb

During construction, it is often necessary for a bricklayer to cut a brick to finish a course next to a door or window jamb. Document answers the common question, “How small of a piece can be cut and still be used effectively?"

TSD 208

Steel Angle Lintels and Longer Spans

Tables give allowable heights of 3” nominal brick (including King Size, Western King Size, and Queen Size), and 4” nominal brick (including modular, utility, and other 3 5/8” thick brick), which will not exceed allowable deflections for steel angle lintels without being attached to wood header beams in the wall. Allowable deflections in the MSJC 1.10.1 are L/600 or 0.3” max. Strength of steel lintels does not govern in these tables. We have limited spans to 12’-0" for economical angle sizes. Longer spans such as those over garage doors should be designed by a structural engineer to carry brick, floor, and roof loads. We recommend a minimum L5x3x5/16 (LLV) to be bolted to the wood header with 1/2" x 3 1/2" galvanized lag bolts at 2’-0” c/c. Some wood header manufacturers will design wood headers to carry brick loads.All steel lintels should be shop-primed with corrosion-resistant primer before placing in wall. Completely cover all steel lintels with flashing and do not trim until after joints are tooled. Place foam bead at end of lintels over 6’-0" long for expansion of steel.

TSD 210

Single Wythe Brick Fences

Contains information and suggested details on single-wythe brick fences, including details that we recommend be included. There is also a design chart showing calculated horizontal reinforcing spacing for various wind load and span conditions, and a chart that shows minimum embedment of piers in soil with at least 3,000 psf bearing pressure. For use by engineers to determine design reinforcement and pier size and depth for local wind conditions and soil properties.

TSD 211

Understanding Soundblox and Soundcell

Like many masonry products, Proudfoot has its own unique nomenclature that describes each type of acoustical masonry unit. The units themselves are manufactured by block manufacturers, such as Featherlite, using forms that Proudfoot delivers to the plant for each production run. In order to place product orders correctly, it is important that the masonry contractor understand the product number for each product listed in the specification, and the particular unit that it represents. This document is intended to show many of the common Soundblox and Soundcell units and their correct designations to assist masonry contractors in ordering the correct units for their jobs.

TSD 212

Fire Ratings for Brick on Wood Framing

In 2006 Southwest Research Institute performed ASTM E119 Standard Test Methods for Fire Tests of Building Construction and Materials for the Brick Industry Association, Reston, VA. All test panels consisted of wood framed walls typical of residential and some commercial construction with three different thicknesses of hollow brick veneer. The tests clearly demonstrate the ability of commonly used anchored brick veneer to resist outside fire exposure of up to one hour.

TSD 213

Paver Efflorescence

Efflorescence is a white deposit of water-soluble salts and alkalis that appear on the surface of masonry products when they dry after being wetted. It sometimes occurs on face brick on buildings, but also occurs on the surface of pavers. Efflorescence is more visible in darker colored pavers, but can be seen on all colors of both concrete and clay pavers. Sources of deposits, removal of efflorescence, and paving design to prevent efflorescence are discussed.

TSD 214

Masonry Veneer Unit Comparison

There are many types of masonry materials that can be made into masonry units and laid up in walls. These include natural stone, fired clay brick, concrete masonry units,and autoclaved silica lime bricks. Each of these materials has its unique properties, which will affect the finished appearance of the buildings on which they are used. These properties include strength, freeze-thaw resistance, color-fastness, resistance to water penetration, and resistance to staining. Each of these materials are manufactured to ASTM standards that establish strength and other requirements necessary to meet the minimum requirements for durability and other factors specific to that product that are required to give adequate serviceability. Digest compares these and other properties that may affect the finished appearance of a masonry product.

TSD 215

Concrete Masonry Compressive Strengths in TMS 602 Masonry Code

There have been several significant changes in the 2013 masonry code and specifications. Table 2 values for f’m in previous editions of the masonry specifications were based on prism tests that did not use consistent bedding practices. Recent prism testing of concrete masonry units has demonstrated higher prism strengths for both type N and for type S and M mortars. This digest lists revisions to the compressive strength, f'm tables for clay and concrete masonry assemblies based on those tests.

TSD 216

Maintenance Schedule for Masonry

Generally, if brickwork is properly designed, detailed and constructed, it is very durable and requires little maintenance. However, many of the other components incorporated in the brickwork such as caps, copings, sills, lintels and sealant joints may require periodic inspection and repair. Neglecting maintenance of these components may lead to deterioration of other elements in the wall. Maintenance of buildings may be broken into two general categories:

  1. general inspection to identify potential problems with the performance of exterior walls; and
  2. specific maintenance to correct problems which may develop.

This Technical Note addresses both general and specific maintenance procedures. A checklist is provided for general inspections and specific repair techniques are described.

TSD 217

Fire Brick, Refractory Mortar and Castable Refractories

The purpose of this digest is to explain which mortar is appropriate for use with firebrick for building fireplace liners, pizza ovens, and other masonry exposed to fire. Acme Brick Company manufactures Everset refractory mortar. It has been used successfully for many years to build brick kilns and other high temperature refractory structures. Fire brick with Everset refractory mortar can be used successfully to build fire-exposed masonry, but only if the mortar joints can be kept very thin. Joint thickness should not exceed 0.125 inch (3 mm). Everset refractory mortar will not dry properly if it is used to fill thicker joints. To build refractory domes in pizza ovens and similar curved surfaces, either fire brick must be cut to precise shapes to maintain thin joints throughout the dome, or castable refractory cement can be used to fill gaps where fire brick to not match perfectly. Everset is not a castable refractory.

TSD 218

Summary of Clay Brick Standards

ASTM standards for clay brick contain the requirements for the physical properties, dimension tolerances, and allowable defects, such as chips and cracks. These requirements cover a broad range of requirements that regulate the durability and appearance of clay brick in each of these categories.This summary lists some of those properties for interested parties who do not need the complete standard. The standards covered in this digest are:

  • ASTM C216 Standard Specification for Facing Brick (Solid Masonry Units Made from Clay or Shale)
  • ASTM C652 Standard Specification for Hollow Brick (Hollow Masonry Units Made From Clay or Shale)
  • ASTM C1088 Standard Specification for Thin Veneer Brick Units Made From Clay or Shale

TSD 219

Summary of Standards for Clay Pavers

ASTM standards for clay pavers contain the requirements for the physical properties, dimension tolerances, and allowable defects, such as chips and cracks. These requirements cover a broad range of requirements that regulate the durability and appearance of clay pavers in each of these categories. This summary lists some of those properties for interested parties who do not need the complete standard. The standards covered in this digest are:

  • ASTM C902 Standard Specification for Pedestrian and Light Traffic Paving Brick
  • ASTM C1272 Standard Specification for Heavy Vehicular Paving Brick

TSD 220

Rain Screen Masonry Veneers and Drainage Walls

Rain screen claddings have gained popularity in recent years. The concept is to provide drainage and air circulation behind the cladding to isolate it from the exterior supporting wall and help prevent moisture migration. They work well for many wall systems, but there may be some unintended consequences that architects should consider.

TSD 222

Storm Debris Resistance of Face Brick

Testing at Texas Tech University has shown that 4” modular face brick veneer can absorb the impact and prevent penetration of the large windborne debris missile specified by FEMA and in the Florida Building Code for Broward and Dade counties. The intent of the code is to prevent windborne debris from hurricane force winds from penetrating the building enclosure.

TSD 224

Control Joints vs. Expansion Joints

Control joints are placed in concrete masonry to help limit cracking due to shrinkage. They also help control cracks from movements other than shrinkage. Control joints get larger as concrete shrinks away from the joints, opening the gap. That is why mortar is allowed, but not required in concrete masonry control joints. Fired clay brick and other ceramic masonry units have a one-time moisture expansion that causes them to grow slightly over several years. Fired clay products do not shrink upon drying as concrete products do.

Expansion joints are placed in clay masonry walls to allow room for the wall to expand. The amount of expansion depends on firing characteristics of the masonry units, but is typically not more than 0.10 inches in 25 ft. Expansion joints will get smaller as clay products expand, closing the gap. For that reason, mortar should never be allowed in brick expansion joints.