Burke Flooring Rubber Tile and Stair Tread Installation - Manual (Page 6)

Page 6
Burke Flooring Products, a Division of Burke Industries
2250 South Tenth Street, San Jose CA 95112
(408) 297-3500
2. BR 725™ Urethane – Solvent Free. This adhesive will operate at
temperatures to 50ºF (7ºC). It can be used where some traces of old asphalt
or "cut back" adhesive remain in the pores of the slab after most of the "cut
back" has been scraped off.
B. Two Part Adhesive Mixing Instructions
1. Two Part Adhesive – The packaged units of epoxy or urethane (BR 721 Epoxy
and BR 725) are marked A or B. The A & B unit should be mixed together
thoroughly and with a rotary motion while at the same time lifting from the
bottom. Use an electric drill and paddle for thorough mixing. After
mixing, the color of the adhesive must be uniform (i.e., no streaking). Never
mix Parts A and B on the sub-floor itself. Once the adhesive is mixed it must
be removed from the container to slow its curing time – pot life is less than 10
minutes for BR 721. The pot life for BR 725 is 40 minutes.
2. Temperature – The sub-floor temperature affects the curing rate of two part
adhesives. Curing will take place between 59ºF (14ºC) and 85ºF (29ºC). The
ideal temperature for the adhesive cure is 72ºF (24ºC). This will normally
take 8-12 hours. At 59ºF (14ºC) cure will take approximately three times
longer for epoxy and about twice as long with urethane. At 85ºF (29ºC) cure
will take approximately half the time. The chart below shows approximate
temperature and appropriate cure times of epoxy and urethane adhesives:
BR 721
ACTUAL FLOOR TEMPERATURE
MINIMUM REQUIRED CURE TIME 59ºF (14ºC) 72ºF (24ºC) 85ºF (29ºC)
Heavy Rolling Stock 4 Days 4 Days 3 Days
Foot Traffic 12 Hrs. 7 Hrs. 6 Hrs.
BR 725 ACTUAL FLOOR TEMPERATURE
MINIMUM REQUIRED CURE TIME 59ºF (14ºC) 72ºF (24ºC) 85ºF (29ºC)
Heavy Rolling Stock 5 Days 4 Days 4 Days
Foot Traffic 16 Hrs. 7 Hrs. 6 Hrs.