Field Observer's/Inspector's Guide And Checklist

1) Observing/Inspecting Masonry Work
2) Products And Samples
3) Masonry Construction
4) Field Testing
5) Workmanship, Protection, Cleaning
6) Field Observer's/Inspector's Checklist

1. Observing/Inspecting Masonry Work

The objective of field inspection is to ensure that quality control is maintained throughout the duration of the construction. By observing the work of the contractor and materials used, the inspector ensures that the intent of the designer and owner, as expressed by the plans and specifications, is satisfied. The inspector should use good judgment to allow the contractor reasonable freedom in techniques, so long as the required results are obtained. He should become thoroughly familiar with the plans and specifications. Since all items are not of equal concern, the inspector should meet with the engineer and architect to establish priorities concerning important parts of the construction.

Generally, the drawings are used to indicate the size and shape of the building, and give graphic illustrations of unit types, sizes, patterns, and configurations. Large-scale details for joints, intersections, reinforcement, anchorage, and flashing should accompany the plans as further guidelines. The specifications supplement the drawings, and establish a quality standard for both materials and workmanship. By the use of reference standards, performance criteria, and prescriptive requirements, the specifier outlines the required products and their method of installation.

Without field inspection, the architect or engineer has no control over the execution of the design. With the increasing complexity of structural designs used in masonry buildings, the need for inspection to assure design integrity extends beyond aesthetics to concern for the public safety.

Responsibility for construction of a building project lies ultimately with the contractor. The architect or engineer is not a party to the construction contract, but acts solely as the owner's representative in the field. As part of the team, the architect can guide the contractor and offer advice and expertise in solving or avoiding potential problems. The architect must also act as interpreter of design intent, and safeguard the project quality by assuring proper execution of the work according to the requirements of the drawings and specifications. The inspector's authority does not extend to supervision of the work, or to revision of details or methods without the written approval of the parties concerned.

Establish priorities concerning
important parts of the construction.

2. Products And Samples

2. 1. Brick Brick should conform to their appropriate ASTM specification, usually either C-62 or C-216. Brick should be clean when they are laid. Dirty brick will not bond well with the mortar or grout

The absorption rate of a brick has an important effect on the bond between brick and mortar. Maximum bond strength and minimum water penetration through masonry occur when the suction of the brick at the time of laying is between 5 and 20 gm. per minute per 30 sq. in. of brick surface immersed in 1/8" of water. Brick having a higher suction should be wetted to reduce the suction. A rough field test is to draws 1" diameter circle on a brick with a wax crayon, using a 25 cents piece as a guide. Place 20 drops of water inside this circle; if the water is absorbed within 90 seconds, wetting is recommended.

Draw 1" diameter circle on brick, place
20 drops of water inside this ...

To check the moisture of high suction brick, the inspector should occasionally break a brick and observe the interior.

Figure 1 (below) shows a saturated condition where the brick has so low a suction that it will float unless the bricklaying proceeds very slowly. Figure 2 shows a dry brick. Figure 3 shows a wet surface but dry core condition which is not recommended unless the moisture extends at least 3/4" into the brick. The reason is that, in warm weather, the brick can too rapidly dry out to condition 2. Figure 4 shows the ideal condition where the core is wet and the surface is damp. One method to achieve this condition is to saturate the brick the day before use.

2.2. CMU Products and Samples. Concrete masonry units on the job site should be protected against wetting prior to use. Preferably they should be stored off the ground as moisture can be absorbed from the ground as well as from rain or snow. Once wetted, units at the job site can be dried, but it may be difficult and time consuming, depending upon weather conditions.

Field inspection of masonry units includes determining that units are sound and free of cracks or other defects that would interfere with the proper placing of the unit or impair the strength or permanence of the construction. Minor chipping is not grounds for rejection unless clearly stated in the specification. Units selected at the job site for laboratory testing should be picked at random so that the sample is representative. An indication of the moisture content of the units can be obtained by breaking a unit and looking for moisture on the newly fractured face which may indicate that a test should be made.

If the manufacturer does not supply test certificates, random samples should be selected and sent to the testing agency for laboratory verification of minimum standards.

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The NW Masonry Guide Table of Contents

Masonry Institute of Washington
Washington State Conference of Mason Contractors