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How to treat damp walls internally

Ever wondered what causes damp walls? Learn the different sources as well as how to treat damp walls internally. With guidance, tips, prices and more.

Frustratingly, many homes throughout the country are affected by damp internal walls. Not only do patches of damp look terrible, but they can also be hazardous to your health and affect the structural integrity of your property. If you’re struggling with these issues, learning how to treat damp walls internally can save your home and your wellbeing.

Let’s take a look further into the causes, signs and fixes for damp internal walls. We’ll also be covering condensation damp, how to repair a damp internal wall and DIY damp proofing. Let’s go!

What causes rising damp in internal walls?

stop damp coming through internal wall

Rising damp is a very common issue, that can affect flats, houses and any other structure. But what causes rising damp in internal walls?

Rising damp starts low and moves up your home’s walls, causing serious issues. Often this is due to your damp proof course failing through poor installation, age, or damage.

Water is very good at working its way into our homes through your damp proof course thanks to tiny tears or mistakes made during the installation process. What’s more, over time, structures near your home (like steps) can also cause water to penetrate your damp proof course. Moisture then begins to seep into your walls, spreading through the materials and causing issues.

If you’d like to learn more about rising damp, visit Richard & Starling’s rising damp guide.

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internal wall with dampWhat causes condensation damp on internal walls?

Condensation refers to patches of moisture that can form on the walls of your home, which can lead to health issues and structural damage. If you’re unsure, you can check whether your walls are damp using your hand or a damp meter.

This frustrating problem can be caused by:

  • Issues with your gutters
  • Damage to your roof
  • Breaks or cracks in your wall’s mortar
  • Damage from fixings in your home usually by screwing or bolting things to your walls

Do internal walls need damp proofing?

If you’re struggling with damp in your home, you may be wondering “how do you stop damp coming through internal walls?” The best remedy here is damp proofing. This can prevent the health, structural and aesthetic issues associated with excess moisture in your home.

Depending on the cause of your moisture issue, you can protect your home and family by using damp proof paint, damp proofing treatments or cavity trays.

How to treat rising damp on internal walls

Rising damp is particularly irritating as it can be quite tricky to remedy. Damp walls, degrading skirting boards, staining and fluffy substances in your plaster are all signs of rising damp and it’s important you act ASAP. Learning how to treat rising damp on internal walls is done by identifying the cause and fixing the issue.

It’s inadvisable to simply get rid of the signs of rising damp, as unless you fix the root cause, it will come back again and again.

Generally, repairing any tears in your damp proof course is the best way of eliminating rising damp. What’s more, if your damp proof course is being bridged by structures next to your home, removing these can also eradicate the cause of rising damp.

Alternatively, if your rising damp is caused by significant damage to your damp proof course, you may need to replace the entire course. We would recommend you hire a professional to install a new damp proof course as this is a difficult, time-consuming job.

If you’d like to try DIY damp proofing internal walls yourself using chemicals, follow the below steps:

  1. Use a drill to make holes that are around 11mm wide in your walls.
  2. Make sure you drill through the external and internal walls (you may need to do this separately).
  3. Always drill using the method and pattern recommended in your damp proof course instructions.
  4. Use a pump that has a good pressure to push the liquid into your walls. This will create a damp proof layer in your walls to stop any moisture coming into your home from below.
  5. Use mortar to fill in the holes you made when damp proofing to prevent rainwater entering your home.
  6. Let the mortar dry before making any further repairs to your walls.
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treating internal wall dampHow to repair a damp internal wall

Once you’ve added a waterproof layer to your walls, preventing any more water from entering your home, you’ll need to know how to repair a damp internal wall. Firstly, you’ll need to completely remove any damaged plaster before beginning your repairs.

Wondering how to repair a damp internal wall? Use the following tips:

  • Locate the cause of your damp walls and fix this before continuing.
  • Buy or hire a dehumidifier to completely dry out the room. If you’re considering hiring a dehumidifier, check out our dehumidifier hire cost guide for prices and information.
  • Use a stain blocker to prevent future staining.
  • Replaster your walls.
  • Redecorate using paint, tiles or wallpaper.
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How to treat damp walls before painting

It’s essential that you tackle the cause of damp before painting or redecorating. If you skip this step, in no time at all, your walls will be damp and stained.

Our full how to treat damp walls before painting guide is the perfect source of useful information and guidance if you find yourself in this situation.

Dealing with damp internal walls professionally

If you’re unlucky enough to have issues with damp internal walls, your best option is to contact an expert. They’ll be able to quickly locate the source of your problem and suggest the best treatment options. This will save you many headaches plus time and energy that could be better spent elsewhere.

To quickly contact a number of highly qualified professionals in your area, enter your postcode below and browse through damp proofers near you.

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How much does it cost to damp proof an internal wall?

If you’d like to have the assurance your damp problem is being dealt with once and for all, working with a tradesperson is a great choice.

So, how much does it cost to damp proof an internal wall? Our damp proofing cost guide is designed to answer this question as well as teach you everything you need to know about damp proofing. The average cost of a damp proofing course is £850, and for more prices, please see our guide.

For further information about this issue, our damp proofing guide is another great resource.

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