In construction, a building or structure is waterproofed with the use of membranes and coatings to protect contents and structural integrity.
Waterproofing is a fundamental aspect of creating a building envelope, which is a controlled environment. The roof covering materials, siding/walling, foundations and all of the various penetrations through these surfaces, must be water-resistant and sometimes waterproof.
Roofing materials are generally designed to be water-resistant and shed water from a sloping roof, but in some conditions, such as flat roofs, the roofing must be waterproof. Many types of waterproof membrane systems are available, including felt paper or tar paper with asphalt or tar to make a built-up roof, other bituminous waterproofing, ethylene propylene diene monomer EPDM rubber, Hypalon, polyvinyl chloride, liquid roofing, and more.
Waterproofing is also used in tanking. Tanking is waterproofing used where there is a below-ground structure and will be sitting in the water table continuously or periodically (This may include basements, split levels in houses, sunken rooms etc.) This causes hydrostatic pressure on both the membrane and structure, and requires full encapsulation of the below ground structure.
Damp proofing – this is waterproofing used where the water table is lower than the structure. The membrane deals with shedding of water and the ingress of water vapor only, with no hydrostatic pressure. Generally, this incorporates a damp proof membrane (DPM) to the walls with a polythene DPM under slab.
Another specialized area of waterproofing is roof-top decks and balconies. Where major problems occur in the construction industry is when improper products are used for the wrong application. However, in Kenya, most problems occur because of taking shortcuts or not doing water proofing at all. While the term waterproof is used for many products, each of them has a very specific area of application, and when manufacturer specifications and installation procedures are not followed, the consequences can be severe.
Areas to waterproof;
- All balconies
- All flat roofs
- All bathrooms/toilets/wet areas on suspended slabs
- Any structure that is below the ground.
Due to waterproofing being a highly specialized field, we always strongly recommend that you sub-contract ALL waterproofing works to a specialist who will give a guarantee, failure to which you know what you will be served in your leaking house… tears sauté.