Hey, I want to share different types of waterproofing solutions that are being used in most of the constructions and in repair sites that would certainly help you to avoid waterproofing failures. Besides, poor quality material and workmanship, inappropriate type of waterproofing chosen for a particular problem/site is another key reason of waterproofing failure.
There are various types of waterproofing used in the Industry but which one to use for particular kind of problem is often make an architect perplexed at design stage itself. Clients’ budget and contractors’ lack of knowledge also confuse the decision makers.
Here are brief, advantages & disadvantages, where to use which kind of waterproofing solutions:
Cementitious waterproofing is one of the most widely used type of waterproofing solutions. Mainly it is being used in sunken portions such as toilets & kitchens, terrace (on mother surface) and basement etc. Though, cementitious waterproofing is recommended for sunken areas but there are lots of failures due to below grade chemicals and poor workmanship. Most of the cementitious coatings are not flexible; in fact some are even rigid. To bear the contraction and expansion process in the structure, it is necessary to have flexible coatings. Flexibility of prepared coating depends on solid content of polymer in chemicals. In repair and maintenance sites, some of the contractor apply cementitious coatings over terraces and leave the surface open. Cementitious coatings are not UV resistance and hence it needs safety plaster over it. Vapor permeability is other necessary feature that a waterproofing coating should contain so that your structure can breathe.
Liquid waterproofing membrane
This is most effective kind of waterproofing. Unlike membrane based waterproofing, liquid applied waterproofing provides seamless layer of protection with highly flexible membrane. Durability and quality of liquid applied waterproofing membrane depend on formulation and polymer used for production by manufacturer. High elongation and UV resistance are some of the key benefits. Recommended for sunken portions at crucial sites, terraces, basements, terrace gardens, swimming pools etc.
Bituminuos based membrane
Bituminuos based waterproofing membrane is one of the traditional methods and still widely used. Though due to poor workman ship and quality of bituminuous based sheets and availability of advanced techniques, Bituminuos based waterproofing is not recommended. Like cementitious coatings, bitumen based membranes are also not UV resistant and hence need safety screed over it. We have witnessed various sites where contractors left the bitumen based sheet open (i.e. without safety screed) and hence sheet could not bear the weather changes and developed cracks in one or two year. Reasons could be lack of knowledge or to reduce the budget of the clients. Budget is one of the important criteria for any decision but a waterproofing failure is always proved to be costlier for client.
Polyurethane liquid membrane
Polyurethane can provide higher flexibility but it is expensive and can be applied on flat roofs. Polyurethane is very critical to moisture content, thus before application, one has to be very watchful evaluating the moisture content in the concrete slab.