plastic backing strip weatherstripping. Do not use neoprene or
polyvinyl chloride weatherstripping where they will be exposed to
direct sun light.
3.2.5
Joint Sealants
3.2.5.1
Surface Preparation
Surfaces to be primed and sealed shall be clean, dry to the touch, free
from frost, moisture, grease, oil, wax, lacquer, paint, or other foreign
matter. Enclose joints on three sides. Clean out grooves to proper depth.
Joint dimensions shall conform to approved detail drawings with a tolerance
of plus 3 mm 1/8 inch. Do not apply compound unless ambient temperature is
between 4 and 32 degrees C 40 and 90 degrees F. Clean out loose particles
and mortar just before sealing. Remove protective coatings or coverings
from surfaces in contact with sealants before applying sealants or tapes.
Solvents used to remove coatings shall be of type that leave no residue on
metals.
3.2.5.2
Applications
Match approved sample. Force compound into grooves with sufficient
pressure to fill grooves solidly. Sealing compound shall be uniformly
smooth and free of wrinkles and, unless indicated otherwise, shall be
tooled and left sufficiently convex to result in a flush joint when dry. Do
not trim edges of sealing material after joints are tooled. Mix only
amount of multi-component sealant which can be installed within four hours,
but at no time shall this amount exceed 19 liters 5 gallons.
3.2.5.3
Primer
Apply to masonry, concrete, wood, and other surfaces as recommended by
sealant manufacturer. Do not apply primer to surfaces which will be
exposed after calking is completed.
3.2.5.4
Backing
Tightly pack in bottom of joints which are over 13 mm 1/2 inch in depth
with specified backing material to depth indicated or specified. Roll
backing material of hose or rod stock into joints to prevent lengthwise
stretching.
3.2.5.5
Bond Prevention
Install bond preventive material at back or bottom of joint cavities in
which no backstop material is required, covering full width and length of
joint cavities.
3.2.5.6
Protection and Cleaning
Remove compound smears from surfaces of materials adjacent to sealed joints
as the work progresses. Use masking tape on each side of joint where
texture of adjacent material will be difficult to clean. Remove masking
tape immediately after filling joint. Scrape off fresh compound from
adjacent surfaces immediately and rub clean with approved solvent. Upon
completion of calking and sealing, remove remaining smears, stains, and
other soiling, and leave the work in clean neat condition.
SECTION 08900
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