Why is replastering necessary following damp treatment?
We are commonly asked why replastering is often necessary following the installation of a damp proof course. The reason is largely due to salt contamination in the old plaster.
It is tempting to believe once you’ve installed a new damp proof course that all your problems with damp have been dealt with and that once your wall has dried out all signs of damp will disappear. Unfortunately, this is not necessarily the case if there are already hygroscopic salts trapped within your wall and plaster.
Why can’t hygroscopic salts be left in your plaster?
Hygroscopic salts located in the ground are dissolved in water before they are transferred to your wall and plaster through the process of rising damp.
The reason that these salts are problematic even after a new damp proof course has been installed is because they absorb moisture directly from the air. This can result in damp patches appearing on your wall even if your new damp proof course is working perfectly. This is known as hygroscopic dampness and is a totally different damp problem to rising damp.
How do we deal with hygroscopic salt contamination?
Removing and replacing any salt contaminated plaster is the only certain way to eliminate hygroscopic salts from an area that has been affected by rising damp. However, whilst plaster is relatively easy for an experienced professional such as ourselves to remove and replace, there is no easy way to remove the salt contamination within the wall itself.
To combat this, out team use a salt resistant plaster mix to prevent any hygroscopic salts from transferring through to your internal wall. If specialised plaster is not used, then you risk the salt migrating to your new decorative surface and causing damp problems in future.
As experienced damp specialists we have helped numerous clients across Dorset and Hampshire resolve their problems with rising damp. We are perfectly positioned to advise you on whether your wall will require replastering and use only suitable products when carrying out our service. Contact us to book a damp survey today on 01202 737739.