When should I worry about damp walls?

Author: Mrs. Eryn Mraz I  |  Last update: Friday, June 19, 2026

Damp on walls can lead to wallpaper peeling, paint discolouration and plaster becoming crumbly. Look out for these signs, particularly when plaster is crumbling low down on walls, as this could be a sign of rising damp.

How do you know if damp is serious?

If it's left untreated, damp can cause black mould, which is dangerous and can lead to health issues. Fevers, coughs, and other unpleasant symptoms can all result from the presence of black mould, so dampness should be seen as a serious issue. Damp walls and surfaces can also cause significant damage to your property.

What percentage of damp is acceptable in walls?

Safe Moisture Levels in Plaster Walls

Ideally, moisture levels in plaster walls should remain between 12% and 15%. Higher levels can cause: Bubbling or peeling paint.

How do you fix dampness in walls?

If groundwater rises up the inner walls of the property this can cause damage to skirting boards, plaster peeling off walls as well as black mould growth. Treatment for rising damp is usually done by one of two methods: Either by having a chemical damp proof course or by having a damp proof membrane fitted.

Can you live with damp walls?

The respiratory effects of damp and mould can cause serious illness and, in the most severe cases, death. The respiratory effects include: general symptoms such as cough, wheeze and shortness of breath. increased risk of airway infections, including aspergillosis (an infection of the airways with the fungus Aspergillus ...

Is This Condensation or Rising Damp?

What happens if you don't treat damp walls?

If rising dampness is left untreated, it can cause serious damage to a building. The moisture that seeps into the walls can rot wood, blister paint and wallpaper, and crumbling plaster. Moreover, rising dampness can also promote the growth of mould and mildew, which may have adverse effects on one's health.

Is it safe to sleep in a room with damp walls?

Sleeping in a damp room can significantly impact respiratory health. The excessive moisture creates an ideal breeding ground for mould and mildew, which release airborne spores.

How much does it cost to repair a damp wall?

The average cost of damp proofing a wall in your house ranges from £300 to £400. However, it can go anywhere from £300 to £5000 for the whole house, depending on your walls' size, the type of damp proofing, and the damage.

Is rising damp covered by insurance?

Does home insurance cover rising damp? In most cases, home insurance does not cover damp for internal or external walls. Buildings insurance policies do not pay out for problems that are seen as the result of gradual deterioration (in other words, wear and tear on the building). Most insurers class rising damp as this.

Will a dehumidifier get rid of damp?

Dehumidifiers seem to be the obvious way of reducing humidity, removing condensation, stopping walls becoming damp and preventing mould. But a more effective solution is to give your home a small but consistent background movement of fresh air. This will help keep your home feeling fresher, healthier and mould free.

What happens if you leave in damp walls?

First thing's first, rising damp will ruin your interior décor, causing the paint to blister and flake off the walls and resulting in peeling wallpaper. In addition to this, damp issues may lead to internal woodwork damage, such as rotten skirting boards and the warping or swelling of doors and door casings.

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.

How do you test for damp walls?

Tape a square of aluminium foil to the wall and leave it there for a day. On inspection, if the side facing away from the wall is wet, you have an issue with condensation. If the inside of the foil is wet, you have penetrating or rising damp.

How do I find out where my damp is coming from?

Signs of damp symptoms will simply keep recurring if the cause of the dampness is not treated. Here's some of most common source of entry: Check for gaps or cracks in gutters and downpipes. Check for signs of water ingress on your roof space such as wet timber.

How much does it cost to damp proof a house?

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.

Can you have damp without mold?

Rising Damp

Therefore it usually only affects basements and ground floor rooms. With the trademark of a “tide mark” low down on the wall, rising damp often leaves a white mark. This is a result of the salt contained within the water. Mould does not usually accompany rising damp as the salt prevents it from growing.

How to fix damp in a house?

Easy ways to ventilate and reduce damp
  1. Air your home regularly. Open doors and windows for 10-15 minutes each morning, or use a ventilation system. ...
  2. Use energy efficient, low emissions heaters. Heat every room being used by someone to at least 18°C. ...
  3. Dry washing outside. ...
  4. Use extractor fans and rangehoods.

Do all old houses have rising damp?

Rising damp is commoner in old (pre-c1919) buildings than new ones but rarer than often supposed. Modern buildings keep water out with a system of barriers: damp-proof courses (DPCs) have been required in walls since 1875 and damp-proof membranes (DPMs) in floors from the 1960's.

Does homeowners insurance cover moisture damage?

Source of damage

If the source of the damage comes from inside your home, such as a water leak from plumbing , a broken pipe or overflowing appliance, you'll likely be covered by your homeowners insurance.

How do you permanently get rid of damp walls?

To resolve rising damp, either a chemical or osmotic damp proofing course (DPC), or a new damp membrane must be installed. A DPC is often used and is injected via holes in the masonry, the DPC repels water whilst a damp membrane acts as a physical barrier to stop damp.

Who treats damp walls?

A damp surveyor will specialise in every damp issue there is, from rising damp, to wet rot and dry rot. 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.

How to remove dampness from a room?

Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don't become sources of biological pollutants. Raise the temperature of cold surfaces where moisture condenses. Use insulation or storm windows.

How to get rid of mold on walls permanently?

The only effective way to permanently get rid of mould problems is by reducing the build-up of moisture in your home. This can only be achieved through better ventilation.

Does damp walls make a room cold?

Damp Could be Making Your Home Cold

Since water has a considerably higher heat conductivity than air, the wall will lose heat more rapidly when it's covered in water. When a wall is wet, the property will lose heat more rapidly than when it is dry.

Previous article
What is the labor cost to replace a water pump?
Next article
What to mop floors with to keep roaches away?