BITUBOND and BITUFLAME CONSTRUCTION JOINT DETAILING
by John Stallard — 1/9/2020
Extended foundation footing
An extruded bitumen fillet is the best option for extended foundation footings, being soft and pliable it can follow the footing foundation undulations without bridging across the low spots, and has the ability being a hot melt application, to bond into the footing and vertical wall junction sealing all cracks, crevices and fill voids at these locations. The extruded bitumen fillet is a natural bed mate with the bituBOND and bituFLAME tanking membrane systems and there will be a natural adhesion further increasing the watertighness at this junction.
Cement plaster and timber fillets are not part of our system and cannot perform in the same way.
Flush Foundation Bandage
For bituBOND tanking, bituBOND membrane is stripped into 200mm wide lengths and applied centralised across the foundation to wall junction, applied with a heat gun and pressure roller to ensure the soft molten bitumen is penetrating into the pores of both substrates and the edges are wheeled into a feather finish.
For bituFLAME tanking, bituFLAME membrane is stripped into 200mm wide lengths and applied centralised across the foundation to wall junction, torchon applied with a pressure roller to ensure the soft molten bitumen is penetrating into the pores of both substrates and the edges are wheeled into a feather finish.
Waterproofing Systems do this because the foundation side of the tanking is often rough, could be slightly burst and has lots of voids between the stone content due to no foundation vibration. Foundations which are not straight and flush with the wall cause flutes in the membrane on the internal concave and stretch the membrane on the external concave so applying 200mm wide underflashing ensures a good seal at this junction before the general application of the membrane system.
Note: These systems will need bitumen solvent primer applied before this detailing is executed.
BITUFLAME INTERNAL & EXTERNAL PRE-FORMED CORNERS
bituFLAME pre-formed corners are very important in bituFLAME tanking systems, particularly in the 2 layer system where a low water table is expected during the winter months, and for the single layer system where a building has quite strong water flow through embankments. For example, in a schist or stoney environment.
The bituFLAME 3mm tanking membrane is polyester re-inforced and very strong, therefore quite hard to cut neatly leading to internal and external junctions mostly if not always having risky detailing. The pre-formed external corners always remove that risk. Being bitumen, they are soft, flexible and will mould any slight deviation in these 90 degree critical angles.