What is Damp Proofing?
Damp Proofing is a general term used to describe methods and treatments of controlling moisture that has built up within walls and floors into the interior of the property. It is important to have damp proofing specialists to tackle your damp problem, from the failure of a damp proof course (DPC) to high levels of water ingress and every other type of dampness in between.
Damp can occur for a number of reasons, but it is typically as a result of a failing damp proof course (DPC), poor ventilation or poor property maintenance. Compared to modern buildings, older housing was not specifically designed to stop damp problems by preventing the excess build-up of moisture. The reason for this is that older properties were built entirely from permeable materials with no attempt at damp proofing, unlike the construction of modern buildings.
Historically, most dampness was caused by the lack of maintenance which then led to leaks. However, the most common causes of damp are usually developed by inappropriate building work that stops moisture from escaping.
What Exactly Is a Damp Proof Course?
With new structures, the wall will include a physical barrier in the form of a damp-proof-course (DPC). However, installing a new physical DPC into an existing structure is expensive and impractical in most situations. An alternative solution is therefore required.
Injected damp-proof-courses are the most practical and cost-effective method of inserting a DPC into an existing wall. Injected into the mortar bed, the chemical diffuses into the mortar to form an effective barrier to rising moisture.
Should a Damp Proof Course Be Re-Rendered?
Although the new DPC is almost immediately effective, hygroscopic salts may still reside within the wall fabric, and as discussed above, they attract humidity held within the air and the wall will still be damp. Protecting the wall finishes will require removal of the contaminated plaster or render and a new Specialist 2 coat render installed. This can then have a plaster set coat and redecorated as required.