Section R607 Unit Masonry
MORTAR PROPORTIONSa, b
|PROPORTIONS BY VOLUME (cementitious materials)|
|MORTAR||TYPE||Portland cement or blended cement||Mortar cement||Masonry cement||Hydrated limec or lime putty||Aggregate ratio (measured in damp, loose conditions)|
|Cement-lime||M||1||—||—||—||—||1/4||Not less than 21/4 and not |
more than 3 times the sum
of separate volumes of lime,
if used, and cement
|S||1||—||—||—||—||over 1/2 to 1/4|
|over 11/4 to 21/2|
- For the purpose of these specifications, the weight of 1 cubic foot of the respective materials shall be considered to be as follows:
Portland cement94 poundsMasonry cementWeight printed on bagMortar cementWeight printed on bagHydrated lime40 poundsLime putty (Quicklime)80 poundsSand, damp and loose80 pounds of dry sand
- Two air-entraining materials shall not be combined in mortar.
- Hydrated lime conforming to the requirements of ASTM C 207.
Unless otherwise required or indicated on the project drawings, head and bed joints shall be 3/8 inch (10 mm) thick, except that the thickness of the bed joint of the starting course placed over foundations shall not be less than 1/4 inch (7 mm) and not more than 3/4 inch (19 mm).R607.2.1.1 Mortar joint thickness tolerance.
Mortar joint thickness for load-bearing masonry shall be within the following tolerances from the specified dimensions:
- Bed joint: + 1/8 inch (3 mm).
- Head joint: - 1/4 inch (7 mm), + 3/8 inch (10 mm).
- Collar joints: - 1/4 inch (7 mm), + 3/8 inch (10 mm).
The mortar shall be sufficiently plastic and units shall be placed with sufficient pressure to extrude mortar from the joint and produce a tight joint. Deep furrowing of bed joints that produces voids shall not be permitted. Any units disturbed to the extent that initial bond is broken after initial placement shall be removed and relaid in fresh mortar. Surfaces to be in contact with mortar shall be clean and free of deleterious materials.R607.2.2.1 Solid masonry.
Solid masonry units shall be laid with full head and bed joints and all interior vertical joints that are designed to receive mortar shall be filled. R607.2.2.2 Hollow masonry.
For hollow masonry units, head and bed joints shall be filled solidly with mortar for a distance in from the face of the unit not less than the thickness of the face shell.
The installation of wall ties shall be as follows:
- The ends of wall ties shall be embedded in mortar joints. Wall ties shall have a minimum of 5/8-inch (15.9 mm) mortar coverage from the exposed face.
- Wall ties shall not be bent after being embedded in grout or mortar.
- For solid masonry units, solid grouted hollow units, or hollow units in anchored masonry veneer, wall ties shall be embedded in mortar bed at least 11/2 inches (38 mm).
- For hollow masonry units in other than anchored masonry veneer, wall ties shall engage outer face shells by at least 1/2 inch (13 mm).