Damp proofing

Damp problems can have several different causes, and treating the visible damage without understanding where the moisture is coming from can lead to the problem returning.

At KDH Plastering & Property Care, I carry out damp remedial work alongside plastering and property repairs. I assess the condition of the wall, existing plaster and likely source of moisture before recommending an appropriate treatment.

Finding the Cause of Damp

A damp patch does not automatically mean rising damp.

Moisture can enter a building through damaged render, leaking gutters, defective pointing, high external ground levels, plumbing leaks, condensation or water penetration around windows, roofs and other vulnerable areas.

Before deciding on a treatment, it is important to consider the location and pattern of the damp, the construction of the property and any obvious external defects.

The aim is to deal with the cause of the moisture, not simply cover the symptoms.

Removing Damp & Salt-Damaged Plaster

Plaster that has been affected by prolonged damp can become contaminated with salts carried through the masonry.

Even after the source of moisture has been dealt with, these salts can continue attracting moisture from the air and may cause staining or damage to ordinary plaster finishes.

Where necessary, damaged plaster is removed back to a suitable background before the wall is prepared for the appropriate replacement plastering system.

Remedial Plaster Systems

The plaster used after damp treatment is an important part of the overall specification.

Depending on the condition of the wall, I can use different systems including Safeguard Hi-Lime Renovation Plaster and specialist sand-and-cement remedial systems incorporating Renderguard Gold.

Renovation plaster provides a breathable, salt-resistant solution for suitable damp-affected masonry, while other remedial systems can be used where a harder, more resistant specification is required.

The system is selected to suit the wall rather than automatically using the same material on every property.

Tanking & Cementitious Waterproofing

In situations where moisture is entering through masonry rather than rising from the ground, a cementitious waterproofing system may sometimes form part of the solution.

These systems are applied directly to prepared masonry to create a water-resistant barrier and can be useful in certain below-ground, chimney, fireplace or difficult masonry situations.

Tanking is not automatically suitable for every damp wall, so the construction and moisture source need to be considered before it is specified.

Penetrating Damp

Penetrating damp is caused by water entering through the building fabric from outside.

Common causes can include cracked or failed render, defective pointing, leaking gutters or downpipes, gaps around windows, damaged chimney areas and other faults that allow rainwater into the wall.

In these situations, repairing the external defect is normally the priority. Internal plaster repairs can then be carried out once the source of water has been addressed and the wall has had an opportunity to dry.

Damp in Older Properties

Older stone and solid-wall buildings require particular care because they often behave differently from modern cavity-wall construction.

Some older walls were originally designed to work with more vapour-permeable materials such as lime mortar and lime plaster. Replacing these with unsuitable dense or impermeable finishes can sometimes contribute to moisture becoming trapped within the wall.

Where appropriate, I can recommend lime or breathable plaster systems rather than conventional gypsum finishes.

Damp Repairs & Replastering

Once the moisture problem has been identified and the necessary remedial work carried out, I can complete the plaster repairs as part of the same job.

This can include removing damaged plaster, preparing masonry, installing the appropriate damp-proofing or remedial system and replastering the affected area ready for decoration.

That means the damp treatment and the finished plaster are considered as one system rather than two unrelated jobs.

Concerned About Damp in Your Property?

If you have damp patches, damaged plaster, staining, salts or recurring problems with a wall, send me some photographs and a description of what you are seeing.

For more complicated problems, a site visit allows me to inspect the wall and surrounding areas before recommending the most appropriate next step.

KDH Plastering & Property Care
Damp proofing, remedial plastering and property repairs across Cornwall and the Plymouth area.