-
Immediately water- and rain resistant
-
Cold-applied
-
Flexible and crack-bridging
-
In combination with BT 26 applicable also on moist surfaces
-
Amount required: 1.08 m2/m2
CERESIT® BT 21 is used for sealing vertical and horizontal surfaces of buildings, structural components and below the ground structures, such as underground car parks and subways. It is suitable for waterproofing basement walls, garage roofs, balconies, terraces, wet rooms and patios. Also used as a sealant against capillary rise of moisture and as a water vapour barrier in floor areas under screeds.
Before installing the BT 21 waterproofing membrane, all mineral substrates must be pretreated with a BT primer. At temperatures above +5 °C, use BT 26 "AllWeather" Primer, at lower temperatures use BT 28 Special Primer (solvent-based).
Slowly and uniformly peel approx. 1 m backing paper off the strip's top edge. Align the strip and fix it to the substrate with the adhesive side down. Continue to peel off the paper and to bond the remaining part of the strip. After that, press the entire strip firmly down, e.g. with a rubber roller.
Use the BT 21 »All-Weather« Waterproofing Membrane only in dry conditions at temperatures from –5 °C to +30 °C (but not in blazing sunshine) and below 80 % relative air humidity.
CERESIT BT 21 is suitable for waterproofing basement walls, garage roofs, balconies, terraces, wet rooms and patios. Also used as a sealant against capillary rise of moisture and as a water vapour barrier in floor areas under screeds.
Ceresit BT 21 can be applied on smooth, cavity-free surfaces such as concrete, screeds, plasters, bitumen, wood, metals, ceramic tiles and thermal insulation. In combination with BT primers it can also be applied on moist and old surfaces down to -5 °C.
Use the BT 21 »All-Weather« Waterproofing Membrane only in dry conditions at temperatures from –5 °C to +30 °C (but not in blazing sunshine) and below 80 % relative air humidity.