Cork insulation; a complete illustrated textbook on cork insulation ...

284 CORK INSULATION
must be applied to the wall at the floor, on a level line, so
that the corkboards on the entire wall area are kept in perfect
alignment and all vertical and transverse joints in the upper
rows are made to fit close and tight.
Prepare suitable Portland cement mortar in reasonable
quantity, sprinkle the wall to be insulated with clean water,
coat one side of each corkboard with a half-inch of Portland
cement mortar. 1\\ the l:()])per method. ]-nt each in prnner posi-
FIG. 127.—ERECTING FIRST LAYER CORXBOARD AGAIXST iMASOXRY
WALL IN PORTLAND CEMENT MORTAR.
tion against the wall, slightly press into place and hold for a
few moments until the mortar begins to set. Keep cement
backing oflf edges of corkboards. Do not "vacuum cup" the
backing before setting the corkboards, by hollowing out the
mortar with the point of a trowel, because it is impossible
to spread out the mortar again in setting the corkboards, and
air pockets behind <strong>insulation</strong>, with disastrous results, will be
inevitable.
Cut a corkboard half-length and with it start setting the
second row on top of the first, thus breaking vertical joints.
As each corkboard is set, butt it tightly at all points of con-
tact against the adjoining boards, but do not loosen boards
already in position. Join the wall <strong>insulation</strong> tightly with the
ceiling, cutting pieces of corkboard neatly to fit and never
using Portland cement mortar to fill in openings between
corkboards or pieces of corkboard.
Give the cement backing ample time to set, say 48 hours.