Advanced concept for commercial waterproofing
Thinking about larger-scale waterproofing, for example apartment basements, or exposed rooftop car park decks: in Australia, a membrane is still the most popular method of ensuring that water doesn’t penetrate the ‘dry side’.
Waterproofing will always be a significant challenge. Not only is it crucial to keep the usable space dry, it is also imperative to maintain the integrity of the structure itself.
Membranes have a couple of inherent challenges.
Firstly, they are costly. Of course, this cost is accepted in most scenarios as being a necessary long-term insurance against collateral damages should water reach the ‘inside’ of the building.
Secondly, membranes are not absolutely fail-safe. If you’re in the industry, does a ‘classic failure’ come to mind at once? And once you’ve got water on the move, capillary action and/or gravity can feed it a long distance from the original entrance point. This makes locating the failure extremely difficult, and the ultimate repair will be much more extensive than the failed section only.
Let’s turn the thought process around.
Can we do away with the membrane? Concrete as a natural untreated material is porous and allows moisture migration, especially when subjected to ground water pressure. BUT … what if we can waterproof the concrete itself?
Concrete has some innate waterproofing capability, although moisture can seep through perfectly intact concrete, given enough back pressure (e.g. forced by gravity).
Ideally concrete's porosity should be permanently sealed against moisture movement within the matrix. This provides a barrier against seepage which is not dependant on membranes or tanking.
Concrete hydrogel treatments are the key to a membrane-free solution. A hydrogel formation can be induced in concrete by means of catalytic water-borne colloidal silicates. The hydrogel completely seals the porosity of the concrete, immobilising the moisture and preventing water movement into or through the slab.
For holistic waterproofing, hydrogel admixture is included in the concrete mix, permanently sealing the porosity through the entire thickness of the concrete. This is valid whether the concrete is of precast or shotcrete construction. Following placement, as curing commences, a further treatment of catalytic hydrogel is spray-applied to the surface. This provides high-quality curing and penetrating hardening of the concrete. Joints and penetrations are sealed with hydrophilic gaskets and polyurethane sealants. The combination of these treatments, proven for over 20 years, gives a long-term high-quality waterproofing result.
It should be noted that the system does not eliminate the need for membranes in every instance. However, it is particularly suited for such projects as non-habitable basements, and exposed car park roof decks, where membranes are an overkill.
Information on this system is available from Markham 1800 693 694.