External Waterproofing

External masonry waterproofing of new build cellars, basements or earth retaining walls has always been a difficult task. Conventional barrier tanking that is subjected to water pressure from the surrounding ground will fail unless the barrier is 100% defect free.  Even a land drain cannot effectively deal with perched or trapped water higher up against the retaining wall. With the rise of local water tables, more and more basements and earth retaining foundation walls are being subjected to hydrostatic water pressure leading to water ingress into the building.

External below ground masonry waterproofing can be achieved using a combination of high quality masonry waterproofing products to create a free draining masonry waterproofing barrier.

Priming:
A spray application of Aida Kiesol silification spray causes the masonry pores to narrow making the surface water repellent. This also chemically binds the bitumen waterproofing product to the substrate.

Primary waterproofing:
Two coat application of one of the plastic modified bitumen coatings to create an flexible high build waterproof coating.

Secondary waterproofing:
Cover the surface with Geodrain cavity drainage membrane that allows water from the surrounding media to freely drain through the filter fabric into the cavity created by the 6mm studs. The water then drops down to the land or to a French drain situated below floor level, which in turn takes the water away to a suitable drainage point. This cavity drainage membrane immediately elevates the hydrostatic water pressure from the building.

The advantage of this external masonry waterproofing system is that a primary and secondary waterproofing barrier is created, thus absolutely minimising the risk of defects. Also the system is highly flexible so if the building settles or moves in the future you can be safe in the knowledge that the external masonry waterproofing will move with the building and remain water tight.