Damp is a pretty common, yet serious issue that homeowners have to deal with. It may occur for a number of reasons, such as; faulty construction, use of poor quality materials, bad design, and certain human activities (condensation from cooking, showers, and dryers). When left unaddressed, damp will not only affect the structural integrity of a building but can also create unhygienic conditions (mould, mildew) that can be bad for health. The best way to solve this is by finding someone who can help in your area, for example, damp specialist London.
Thankfully, there are several ways you can prevent dampness and save your home from structural damage. Some of them are;
Surface Treatment (Coating)
This involves filling up the pores of the surfaces that are subjected to dampness. Water-repellent metallic soaps like aluminium and calcium stearates and oleates are highly effective in protecting against the ravages of heavy rain. Lime cement plaster is another very affordable material that is used for surface treatment.
When walls are plastered with cement, lime and sand (in a proportion of 1:3:6), they tend to offer good resistance to dampness caused by rain. Cement coating, transparent coatings, varnishes, paints and bituminous solutions are all materials that fall under this category.
Damp-Proof Course (D.P.C.)
D.P.C’s are membranes or layers of water-repellent materials that are placed in a building’s structure at the various locations where water entry is suspected. For buildings without basements, the ideal placement of the D.P.C should be at the plinth level (the level of the ground floor of a building).
However, with building structures that have no plinth level, the D.P.C is laid at a minimum of 15cm above ground level. The D.P.C is also provided vertically and horizontally on walls and floors. In terms of D.P.C materials, they can be either rigid (cement concrete blocks, stone slates, terra-cotta blocks, special bricks, mortar, dense cement concrete, hollow tiles, etc.) or flexible (bituminous sheets, metal sheets, PVC sheets, plastic sheets, etc.).
Integral Damp Proofing
This typically involves the addition of certain waterproofing compounds to the concrete mix in order to increase impermeability. Usually, one kg of waterproofing compound is mixed in with a bag of cement to render the concrete or mortar waterproof.
These waterproofing compounds are available on the market in either liquid or powdered forms. Some of them are made from clay, lime and sand, and they can help fill the voids in the concrete mix to make it more waterproof. These compounds also come in forms like aluminium sulphate, alkaline silicates, and calcium chlorides which chemically react with the concrete to make it waterproof.
This damp prevention method involves the application of an impervious layer of fine aggregate mix or rich cement mortar (1:3) over exposed concrete surfaces, cisterns and pipes. This technique uses an impervious layer that has a high compressive strength (600 to 700 kg/cm2), so it can also be used to repair and recondition old concrete works.
This is when two parallel walls or skins of masonry are separated by a cavity or continuous space of air. The goal here is to prevent the transmission of dampness from the outer walls to the inner walls. Cavity walls offer a host of benefits. Some of them are; good insulation against heat and sound, minimal penetration of outside moisture, better comfort and hygienic conditions for buildings, and reduced effects of efflorescence.
Pressure Grouting (Cementation)
This method of damp prevention uses pressure to push a mixture of cement, sand and water into the voids, fissures, or cracks that are present in the ground or structural component of a building. This treatment is done to prevent moisture penetration, and it can also be used to repair structures, form water cut-offs to prevent seepage, and consolidate the ground to increase its bearing capacity.
As a homeowner, one of the best ways to save your property from structural damage is damp prevention, and diagnosing the cause, and you can do this effectively by considering the methods mentioned above.