We get called out on many occasions to investigate sources of damp any what may be causing a building to become susceptible to it. On many occasions, particularly in older houses, rising damp has indeed been the source of the problem and we have had to perform a chemical injection remedial solution, followed by associated re-plastering works.

However, damp is not always attributable to rising damp any the failure of any damp proof course that may be present. Many homeowners have been told that they have rising damp but in actual fact, it couldn’t be further from the truth.

Here at 4K Construction, as Liverpool damp proofing contractors, we don’t just see damp walls and assume that the cause can only be one thing, We will investigate the source and find exactly what it is that’s causing the problem.

Rising Damp

Rising damp usually travels approximately a metre up from the ground floor walls when present and is usually due to DPC failure. However, damp can also be caused by other methods such as bridging. This is when the existing damp proof course (usually 150 mm from ground floor level) has been bridged by something like soil or paving stones. Essentially, if the floor outside is higher than the damp proof course level then it may be possible for damp to travel past the DPC and into your property and spoil the walls. The plaster would become wet and start smelling very musky. This is a pretty good sign that something is wrong.

How Can We Check The obvious?

We should mention at this stage now that this article is not meant to preach to you and give you a whole bunch of technical goo ga that will probably not mean very much to you anyway, but instead to just simply give you a basic understanding of how damp can be caused and what to look out for.

Go outside to the property exterior and check the ground levels. How high are they? Are they within 150 mm of the DPC? Can you see the DPC? Is there a buildup of plants of soil towards the walls of your house?

If you are wondering how to recognize what the DPC looks like, then depending on the age of your property, this may either be slate, bitumen, plastic or you may even see signs of a previous chemical injection course which will be identifiable by normally 12mm drill holes running along the wall horizontally and also some going vertically towards the end of a building where it adjoins another property.

An obvious cause of damp would be if soil was packed up against the wall. This would almost certainly allow damp to bridge over the existing damp proof course causing the plaster to spoil on the inside. The simple remedy in this case would be to remove the offending soil from the exterior and ensure the DPC is obstructed in any way. This is not a guarantee that there is no other source of damp, but before splashing out on a new DPC, it makes sense to explore all avenues. 4K Construction would advise you on this accordingly in order to make sure the correct course of remedial action is taken.

Any damp above 1 metre or so will not be rising damp but more than likely attributable to something else like, cracked render, a leaking downpipe, or perhaps even a blocked cavity. This may then allow water to penetrate the brickwork and cause the dampness. Commonly known as penetrating damp.

After resolving the actual cause of damp there is then the matter of what remedial action to take. If it is rising damp will you have a physical DPC? a chemical injection? mmmm.. all of this will need to be considered. And don’t just assume that because you’ve had a new DPC, that the problem will magically go away as tomorrow, I will tell you about one of the biggest causes that can lead to a new DPC, failing in every way.

Read more tomorrow………….