Type A Barrier Protection – External and Internal Waterproofing
Damptec has recently completed the external and internal tanking of a garden studio in Greater Manchester. We recommended a combined waterproofing system including walls and floor:
- Type A: Barrier Protection – external waterproofing
- Type A: Barrier Protection – internal waterproofing
This design solution applies where external ground levels are above the internal slab level.
It is worth noting that major third part warranty providers such as NHBC, Premier Guarantees and LABC have insisted for some time on the installation of combined protection as a fundamental condition of their warranty. They also require that a CSSW qualified waterproofing design specialist be involved at the design stage.
Specification
WATER PROOFING Type A: Barrier Protection – external waterproofing
We applied a primer to all surfaces in a spray coat application. We then applied Hydrobond 2K-Flex to the earth retaining walls. The membrane comprises two coats, with the first cost reinforced with mesh membrane to achieve a 4mm cured film.
We then installed Newton 410 Geo-Drain Quattro with geo-textile filter sheet over the primary external waterproofing membrane (see photo).
The GeoDrain is a drainage membrane not a waterproofing membrane. Primary waterproofing of the structure should be achieved with HydroBond 2K-Flex liquid applied membrane.
This tanking system required a serviceable drain positioned below the slab level to run around the perimeter of the retaining walls.
WATER PROOFING Type A: Barrier Protection – internal waterproofing
We applied a primer to all surfaces in a spray coat application followed by:
Newton 107F – a highly flexible cement based waterproofing slurry and
Newton 912-RT reinforcement tape used to reinforce Newton 103-S and Newton 107F across construction joints and any changes in direction.
We worked closely with John Newton Waterproofing in drawing up the specification to meet our client’s requirements. Each project is different and requires bespoke detailing without compromising the waterproofing element of the design.