We first became involved in deck waterproofing by inspecting and specifying remedial solutions for existing decks which had failed, allowing water penetration. These days we offer systems for installation in new construction, and still attend to those that suffer issue.
As with the majority of barrier based tanking systems, part of the design should involve consideration of how to minimise standing water and resultant pressure upon the tanking. This is often given little thought (as is the case with many tanking systems!) and issues occur. Given our experience of what creates problems, we are accutely aware of what is necessary to avoid them in our designs.
We don’t employ single ply roofing membranes, our David Hockey who was in private practice as a Chartered Building Surveyor for six years inspected various problem properties. The same is true of adhesive (bitumen) sheet membranes, too many laps and joints which form weak points.
Our preference is to install a cementitious system which contains an acrylic resin, granting substantial flexibility. This can easily be detailed around complex shapes (as opposed to sheet membranes) and being applied in a ‘liquid’ state, has no laps and joints.
Part of the benefit of the system is it’s flexibility and in this I do not mean the physical ability of the system to bend, more specifically it is tolerant of varied temperatures and being water based there is no chemical cure to manage or substantial sensitivity to installation over damp substrates.
It can be tiled over directly, coated via systems allowing pedestrian traffic or vehicular traffic. It can even be employed in association with systems design to bond to and waterproof tarmac, something which we have put to good use on a complicated remedial scheme.
Large areas can be treated quickly and easily and the material cost is reasonable.
We have also sucessfully employed a polyurea based elastomeric system which is visible in the photo below, but this is now the exception as opposed to the norm.
This is a few example photos from a city centre apartment building where the driveway runs through the building, including an open air aitrium, to a car park at the rear. Habilable basement space resides below the driveway and these suffered water penetration from above. While these photos show a specific part of the project, the deck works were far reaching and there were a number of complicated details and problems which we sucessfully resolved.