Fixing & treating penetrating damp

Help, Information & Guidance for Homeowners

Treating Penetrating Damp

Penetrating damp can happen when structures are exposed to wind driven rain or where building defects allow water to get into the fabrics of the building.

Lack of repairs and maintenance coupled with poor building practice, design and the inappropriate use of building materials can make some buildings susceptible to rainwater penetration.

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Firstly: Prevention is better than cure

Maintenance, good housekeeping and the use of the right products and building materials when undertaking repairs, renovations and extensions is the best way to prevent water ingress.

Keeping roofs, gutters, gullies, hoppers, downpipes and parapets clear of obstruction and able to discharge water efficiently is of paramount importance. Keeping brickwork, pointing and rendering in good condition can be equally important.

Autumn leaves, wayward tennis balls and moss from the roof are often the precursors to water getting into the building. Other less maintainable things such as weathering and the processes of structural movement can also lead to water ingress.

Dealing with the effects of rainwater penetration is seldom quick, cheap or easy. Not only will the cause of the penetrating damp need to be found and rectified, but the full extent and implication of the water ingress will also need to be explored and understood before the building can be dried out and repaired.

Key to the successful treatment of penetrating damp

As with any damage caused by water in buildings, the key to a successful long term repair is a detailed understanding and investigation of the cause of the water ingress.

With so many factors affecting the building's ability to manage rainwater, the possibilities and combinations of defects are limitless. It is essential that the causes of the penetrating damp are fully appreciated, explored and remedied before any reinstatement works are undertaken. This investigation should be undertaken by a specialist surveyor.

Checking the roof, walls and internal areas are all important. Sometimes using a hose pipe or a watering can may help to establish the point of water ingress and guide yourself (or a professional surveyor) to establish the severity and extent of a problem.

There is often a need to open up and look behind wall finishes and ceilings and gain access to voids and concealed structures before the full cause and full extent of any damage caused by rainwater ingress can be fully appreciated.

Treating & repairing a property affected by penetrating damp

Rectifying the initial cause of the water penetration is essential if the repairs that follow are to be successful.

The repair and the renovation of the building envelope, pipework, rainwater goods, roof and building fabrics, etc. may prevent water ingress however it may also be necessary to consider design alterations, changes in materials or the adoption of new systems coupled with a programme of planned maintenance in order to permanently control or eliminate rain water penetration.

The introduction of new barriers, waterproofing products or materials that keep water out as well as techniques that will accelerate drying if water gets in, can also be highly effective where simple building repairs, maintenance and redesign prove inadequate.

Wet plaster will often have to be removed, the condition of building timbers will need to be assessed and any decay seen in timbers (such as wet rot or dry rot) treated and repaired. The building fabric should be allowed to dry properly before the building is repaired and made good.

The materials, processes and techniques adopted to rectify the effects of water penetration will be influenced by the existing building, its use, the ability to maintain it and the needs of the individual(s) working or living there.

A specialist who provides a successful remediation strategy will take account of these factors before rectification works are carried out.

Find local penetrating damp specialists

If you are looking to find a damp related specialist to investigate or treat your potential penetrating damp issue, then you can use the search tool below to find local & qualified damp specialists near you. Simply put in your postcode and run a search.

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Professional Damp Guidance

For professional tradesmen or contractors looking to find out more technical detail about penetrating damp and other forms of dampness, visit our professional guidance section.

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