Can penetrating damp be fixed?

Author: Dr. Charity Carter Jr.  |  Last update: Tuesday, May 26, 2026

Damp patches on interior walls increase in size during periods of heavy rain. The best way to treat penetrating damp is to apply a water-repellent treatment like Stormdry Masonry Protection Cream to halt further dampness and allow walls to dry out.

How do you repair penetrating damp?

For penetrating damp, the repairs may involve sealing any cracks or defects in the walls, windows, or roof. Waterproof paint or render can provide an additional layer of protection.

Is penetrating damp expensive to fix?

Penetrating Damp Internal Wall Treatment

Costs vary significantly between areas and suppliers, but a rough average is around £70 per metre of the treated wall or around £280 per wall. The costs could easily reach several thousand pounds if you need to treat every wall.

Is penetrating damp serious?

What is penetrating damp? Penetrating damp, otherwise known as lateral damp, is the development of moisture through the walls and roof or below ground area of a building. Like most cases of damp, if left untreated it can cause problems for the structure and significant damage to the fabric of your home.

How do you dry out penetrating damp?

Open windows and doors to allow air to circulate freely, and use fans to speed up the drying process. If possible, use a dehumidifier to remove excess moisture from the air. A dehumidifier absorb moisture from the air, which helps to reduce dampness and prevent mould growth.

How to Stop Damp Penetrating Brickwork

Do you have to Replaster after penetrating damp?

Standard plasters, such as Carlite, should not be used after a damp treatment as they cannot prevent the migration of hygroscopic salts. Failure to apply a salt retardant plaster after treatment is the most common cause of continuing damp problems after a remedial damp proof course has been installed.

Will a dehumidifier help with penetrating damp?

Other problems related to damp such as rising damp and penetrating damp are something that a dehumidifier cannot deal with. Having structural defects at your property will need a professional to provide an inspection at the property and identify what remedial action needs to be taken to resolve the problem.

Does homeowners insurance cover penetrating damp?

Most buildings and contents home insurance policies won't cover you for damage caused by damp and condensation. When you apply for home insurance, you need to agree to a list of assumptions, and one of them is that your home is in a 'good condition'.

How much does a damp specialist cost?

Damp specialists offer solutions such as damp proofing, waterproofing, and moisture control, ensuring your property remains safe and healthy. Hiring a damp specialist typically costs between £300 and £5,000, though this can increase for larger or more complex projects.

Will tanking stop penetrating damp?

Tanking is a reliable way of dealing with the effects of penetrating damp once the root cause has been fixed.

Who is responsible for penetrating damp?

Structural problems in your property that cause damp, penetrating damp or plumbing / construction damp will usually be the responsibility of the landlord, however this is not necessarily the case when it comes to condensation.

Can you paint over penetrating damp?

Unfortunately, you can't just paint over damp or mould in the hope it will disappear. Even if you use waterproof paint, it can still seep through over time. Depending on how bad the problem is, you may be able to remove the mould by cleaning the area without repainting.

How do you cover penetrating damp?

Treating bricks with a breathable masonry protection cream is the best way to protect your property from penetrating damp when property maintenance is not the root cause. Masonry Protection Cream provides protection from rain penetration by lining the pores of the masonry to form a water-repellent silicone matrix.

What is the best product for penetrating damp?

Microshield. Permagard's Microshield is an effective high-performing water repellent suitable for external use on masonry materials such as brick, concrete and stone. In one single coat, this microporous water repellent will protect masonry materials against penetrating damp.

How do you find the source of penetrating damp?

How to Identify Penetrating Damp?
  1. Damaged Internal Decoration - deterioration and staining internal wall.
  2. Damaged Plaster - blistering, salting and disintegration.
  3. Rotting Skirting Boards or Floor Timbers – wet rot decay can develop as a result of moisture saturating timber.

Why is water seeping through my wall when it rains but no leak?

Over time, bricks can crack, and mortar can erode, creating pathways for water to enter. Pay special attention to any visible cracks, gaps, or crumbling mortar. Gutter and Downspout Inspection: Faulty gutters and downspouts can direct water towards the wall instead of away from the property.

How to fix penetrating damp?

Damp patches on interior walls increase in size during periods of heavy rain. The best way to treat penetrating damp is to apply a water-repellent treatment like Stormdry Masonry Protection Cream to halt further dampness and allow walls to dry out.

How do I find a reputable damp specialist?

Top tips on finding reliable damp experts

Find out how long they've been in the business and what they specialise in. Contact at least three damp surveyors. Contact multiple damp surveyors to get like-for-like quotes on your damp problems. Check their qualifications and training.

Can you live in a house with rising damp?

Rising damp can be a serious problem, as if left untreated it can lead to structural issues. The damage it can cause to your plaster, flooring and decorative finishes as well as the smell also makes it very unpleasant to live with.

How much does damp proofing cost?

The average cost to damp proof an average-sized property is around £250-£2000. However, there may be some additional costs that you may also need to think about, such as re-plastering or re-rendering. These additional jobs could increase the overall cost of the work by a substantial amount.

Does homeowners insurance cover water leaks under foundation?

Homeowners insurance generally does not cover maintenance issues or wear and tear. So, if a slab leak results when tree roots damage your plumbing, or from plumbing lines that are simply past their prime, a typical homeowners insurance will not pay for repairs.

How to dry out penetrating damp?

Place one or more fans in front of the damp spot and turn them to their highest setting. This helps dry the wall and also gets moisture out of the air. If the fan has an oscillation feature, you can use this to clear more than one damp spot that is within its reach.

What machine gets rid of damp?

Dehumidifiers work by getting rid of excess moisture that's in the air. And that can help to stop mildew and mould from growing, as well as reducing any musty smells. It does this by drawing in air from the room it's in, which is then passed over a cooled coil.

Can penetrating damp spread?

It is possible that penetrating damp can come from defects in a neighbouring property especially if you live in a terraced or semi detached home. Once damp has been absorbed by a properties brickwork and pointing, it will spread through any other absorbent material it can reach.

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