Masonry Magazine July 1969 Page. 21
NCMA TEK 13
An information series from National Concrete Masonry Association.
© 1969, National Concrete Masonry Association
Details for Building
Dry Concrete Masonry Walls
BACK STOP MATERIAL
METAL
WINDOW
SEALANT
L
DRIP NOTCH
SILL
FLASHING
FLOOR
1/2" EXPANSION
JOINT
FILL
H₂O-PROOF
FILM
DRAIN TILE
LAID IN POROUS
BED; JOINTS COVERED
WITH ROOFING FELT.
FOR BELOW GRADE
Two coats of hot bituminous material over
Two coats of portland cement plaster
May, 1969
Concrete Units
The function of an exterior wall is to provide a barrier between indoor and outdoor environments, so the indoor environment can be adjusted and maintained within desirable limits. This definition includes control of water vapor flow and rain penetration. Control can be achieved at acceptable initial and maintenance costs, using concrete masonry and giving some modest attention to the details of construction.
Flashing
Wall flashing is installed to collect moisture that may penetrate a masonry wall and divert it out, generally through weep holes. The required flashing will vary for areas of different rainfall and wind pressures. The following recommendations apply to areas of severe exposure, such as the Gulf Coast, Atlantic Seaboard, and the Great Lakes. Where exposure is slight, internal flashing, such as lintel or sill flash-flashing, may be eliminated or reduced to a minimum.
Installation
Masonry should be free of projections that might puncture the flashing and reduce its effectiveness. Through-wall flashing should be placed on a thin bed of mortar with another thin bed laid on top of it to bond to the next masonry course. Seams in the flashing must be completely bonded to prevent