Dealing with damp What's the best way to deal with damp?

Damp wall

Damp can cause serious damage to your house so it's vital to deal with it.

How to treat damp depends on the type of damp that's affecting your home. You may also find that you have more than one kind of damp, making the solution more complicated. In most cases of damp, you'll need to consult a builder, surveyor or specialist damp company. 

You can find recommended builders, surveyors and damp-treatment companies in your area on our Which? Local website. If you're not already a member, sign up for a £1 trial to get instant access to all of Which.co.uk, Which? Local and receive Which? magazine.

Before you call out a damp specialist, take a look at How much does it cost to repair damp? to see the results of our undercover damp-proofing investigation, which found that households could be paying for unnecessary treatment. 

How to deal with condensation

  • You can improve a condensation problem with better ventilation. If you do not have a bathroom or kitchen fan you should consider installing them as these two rooms are responsible for most moisture in a house. Dehumidifiers can also help - read our Best Buy dehumidifiers reviews  and what to look for in our guide to buying a dehumidifier.
  • You may also find that having you heating on constantly at a lower heat is better than having it switching from high to off. For recommendations of the most energy efficient models see our reviews of Best Buy boilers and portable heaters.
  • As cold spots on walls increase condensation, better insulation may improve it. So having cavity wall insulation or specialist insulation materials fixed to the outside of your house can help. For information about improving your insulation see our guides to how to buy loft insulation and how to buy wall insulation.

How to deal with rising damp

To deal with rising damp you have to make sure that your damp-proof coursing is working. If you have a perfectly good damp-proof course (you will need an expert to confirm this), you can solve the problem simply by digging away the soil on the exterior side to the damp wall to below the level of the damp-proof course.

If your damp-proof course isn't working effectively you may need a new one. The most common remedy is for a builder or damp specialist to drill holes in your wall and inject damp-proof cream, but there may be alternative solutions. 

How to deal with penetrating damp

You'll need to work out the cause of penetrating damp before you can treat it. Start by examining your gutters and downpipes for leaks or cracks. Check the roof – including the pointing (gaps between tiles) and flashing (where a roof meets the wall of a chimney). Check window frames and doors to see if there are any gaps.

Once you've found where water may be leaking through to your walls, you'll probably need to ask a builder to repair the fault. The solution depends on how water is entering walls, so could include installing new guttering or repointing your roof.

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