UNIFORM BUILDING CODE STANDARD NO. 24-40 IN-PLACE MASONRY SHEAR TESTS

The bed joints of the outer wythe of the masonry shall be tested in shear by laterally displacing a single brick relative to the adjacent bricks in the same wythe. The head joint opposite the loaded end of the test brick shall be carefully excavated and cleared. The brick adjacent to the loaded end of the test brick shall be carefully removed by sawing or drilling and excavating to provide space for a hydraulic ram and steel loading blocks. Steel blocks, the size of the end of the brick, shall be used on each end of the ram to distribute the load to the brick. The blocks shall not contact the mortar joints. The load shall be applied horizontally, in the plane of the wythe, until either a crack can be seen or slip occurs. The strength of the mortar shall be calculated by dividing the load at the first crack or movement of the test brick by the nominal gross area of the sum of the two bed joints.

UNIFORM BUILDING CODE STANDARD NO. 24-42 POINTING OF UNREINFORCED MASONRY WALLS

POINTING

The old mortar should be cut out, by means of a toothing chisel or a special painter’s grinder, to a uniform depth of 3/4", or until sound mortar is reached. Care must be taken not to damage the brick edges. All dust and debris must be removed from the joint by brushing, blowing air or rinsing with water.

Mortar mix shall be Type "S" or "N" proportions as called for in the construction specification, The tuck-pointing mortar should be pre-hydrated to reduce excessive shrinkage. The proper pre-hydration process is as follows:

All dry ingredients should be thoroughly mixed. Only enough clean water should be added to the dry mix to produce a damp, workable consistency which will retain its shape when formed into a ball. The mortar should stand in this dampened condition for one to one and one-half hours.

The joints to be tuck-pointed should be dampened, but to ensure a good bond, the brickwork must absorb all surface water. Add water to the pre-hydrated mortar to bring it to a workable consistency which is somewhat drier than conventional mortar. The mortar should be packed tightly into the joints in thin layers not to exceed 1/4 inch. Each layer should become "thumbprint hard" before applying the next layer. The joints should be tooled to match the original profile after the last layer of mortar is "thumbprint hard".

RELAYING OF BRICK

Replacement bricks must match the originals with respect to size, color, and texture where exposed. A tuck-pointing tooling chisel should be used to cut out of the mortar which surrounds the affected units. Power driven impact tools are not allowed. Once the units are removed, all of the old mortar shall be carefully chiseled out and all dust and debris shall be swept out with a brush.

If used brick is to be relayed, it shall be cleaned of all old mortar. The brick surfaces in the wall shall be dampened before new units are placed, but the masonry should absorb all surface moisture to ensure a good bond. The appropriate surfaces of the surrounding brickwork and the replacement brick should be buttered with mortar. The replacement brick should be centered in the opening and pressed into position. The excess mortar should be removed with a trowel. Pointing around the replacement brick will help to ensure full head and bed joints. When the mortar becomes "thumbprint hard", the joints shall be tooled to match the original profile.