damp above window

Damp Proofing

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Damp Proofing

Have you spotted damp patches, mould and rotting timber in your property? If so, you will likely need professional damp proofing treatment to solve the problem.

Damp proofing is an umbrella term that refers to any method used to treat or prevent problems caused by moisture ingress or excess humidity. The key to providing the correct form of damp treatment is correctly identifying the cause of your damp problems.

Whether it is rising damp, penetrating damp, or even condensation that is causing problems in your property, our fully trained and qualified specialists will diagnose the issue and create a custom treatment plan to leave your home fresh, safe, and dry.

What Causes Damp Problems on Internal and External Walls?

More often than not, damp walls are caused by penetrating damp, rising damp or condensation. These damp problems result from water ingress from an external source, ground water rising up through capillary action or inadequate ventilation.

Rising Damp

Rising damp only ever affects the ground floor. You can read more about the signs and symptoms of rising damp on our dedicated page, however the two main problems associated with this type of damp areare tide marks on the wall that extend to around 1 metre from the ground and white salt deposits on walls.

Rising damp normally occurs when an existing damp proof course (DPC) has been bridged or damaged in some way.

Penetrating Damp

Water leaking in from outside the property is the main cause of penetrating damp. This will usually manifest as localised damp patches on a wall or ceiling.

Broken downpipes and gutters, cracks, faulty joints and corroded seals can all contribute to penetrating damp in a property. Leaks from inside can cause problems too, and wet rot can often accompany damp from faulty plumbing or leaking washing machines and showers.


Condensation is caused by excess humidity and poor ventilation. It also creates the ideal conditions for black mould to grow. The key to solving condensation is achieving consistent relative humidity. This can often be remedied with DIY or lifestyle changes, but in serious cases treatment will require the installation of mechanical ventilation units.

Types of Damp Treatment

Just as there are several causes of damp, there are several treatments and it is important to choose the correct one.

Damp Proof Course

A common treatment for rising damp is a Damp Proof Course (DPC). Most properties should have evidence of a DPC about 150mm (6inch) above ground level. This may be seen as a slightly thicker mortar course with evidence of a slate or bitumen sheet. These materials are fairly resilient, however they can degrade, become damaged or bridged by modifications, leaving your home vulnerable to rising damp.

To solve rising damp we usually inject a silicon remedial damp proof course which creates a barrier, effectively preventing moisture from seeping into, and damaging, affected walls. DPC injection is fast acting and permanent. It also allows affected  walls to be redecorated shortly after installation.

Mechanical Ventilation

Improving ventilation in your property can be as simple as opening windows more often, adjusting the vents in your windows or removing debris from air bricks. However, some condensation and black mould problems will simply not go away until mechanical ventilation is introduced. Positive Input Ventilation units actively optoimise the relative humidity of the air in your property reducing the chance of condensation and black mould.

How Much Does Damp Proofing Cost?

We are often asked “how much does damp proofing cost?”, unfortunately due to the number of variables that have a direct impact on pricing, we cannot provide an estimate without visiting the property.

To give you an accurate quotation, one of our CSRT and CSSW qualified surveyors will conduct an extensive survey of your property.

The list of factors which will contribute to the overall cost of damp proofing are:

  • Size of Damp Problem - The size and extent of the damp problem within your property contributes to the overall pricing of the remediation.
  • Type of Treatment - The type of treatment will determine the overall costs of our services. For example, our rising damp treatment costs will differ from our basement waterproofing costs.
  • Plaster Removal and Replacement - Removal of plaster and subsequent replastering will also add to the cost of any damp proofing work.

Our Damp Proofing Surveyors

Rentokil have been treating damp, wet rot, dry rot and woodworm across the UK for over 60 years, providing every customer with high quality, reliable solutions to their problems. Our damp proofing specialists are known for providing outstanding service, guaranteed to protect your home for many years to come.

All of our surveyors are highly trained professionals in remedial damp proofing for residential and commercial buildings. We are accredited by a number of trade associations, certifying us as one of the most reliable and effective property care experts in the UK. Our damp proofing specialists are not only able to provide an expert service; they also keep you in the loop throughout the whole restorative process – explaining the procedures to make sure you’re both completely on the same page.

Contact our Damp Proofing Specialists

Our local branches of Rentokil Property Care are waiting to take your calls and online enquiries to provide all the guidance, advice and help you need to treat your damp problems.

Quite simply our long and distinguished record of success, long lasting guarantees, and outstanding customer reviews mean that there is no better damp proofing company out there for you to entrust the health of your home too. Contact your local branch today on 0800 0121 437 or click the button below to get a quote for a damp proofing survey.

1. Contact

Get in touch with us and we will arrange for your local team to contact you. 

  • Local surveyors 
  • Calls returned within 24 hours (Mon - Fri)

2. Survey

Our surveyors will discuss your damp problem with you & provide you with a quote and recommendations. 

  • Damp proofing survey appointments at a time convenient to you 
  • Tailored damp proofing solutions  
  • PCA certified

3. Treatment

Our PCA certified technicians will provide your damp proofing treatment. 

  • Damp proofing appointments at a time convenient to you 
  • Environmentally sensitive approach. 
  • Child & pet friendly treatments.

4. Aftercare

Following any guarantee treatment, you can be reassured of our long-term care

  • Guaranteed solutions for up to 30 years 
  • Prevention advice
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