Can damp proofing be done from outside? And can you DIY?

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In this article, we are going to be looking at methods of damp proofing your home from the outside. Most of these are damp proofing methods that are reasonably affordable. They are also options that someone with a basic amount of DIY knowledge can do. Finally, we’re going to discuss getting the right diagnosis for the damp causing your issues. Let’s jump right in and see what damp proofing methods are available for the outside of your building.

Damp proofing can be done from outside of a building. In fact, in most cases it is the easiest way to damp proof a property. Whether the property has had damp for years or you have caught it early, damp proofing the outside is a great way of keeping the damp out.

Of course, you must make sure that the interior of a building is thoroughly dried out too. Depending on how bad your damp issue is, this could include carrying out cosmetic repairs inside your property. However, this is repairing the damage caused by damp. It isn’t actually protecting your building from damp.

Some common ways of damp proofing from outside

Below are a few common ways to protect your building from damp:

  1. Chemical DPC – This is a damp proof course that is injected into the building. This can be done either internally of externally. It forms a barrier which will prevent moisture from the ground entering your building. This makes it a perfect solution for stopping rising damp. To learn more about chemical DPC click here
  2. Exterior damp proof paint – This type of paint is widely available and is a great preventative measure for damp. It is a great way to prevent penetrating damp and can offer a complete barrier from the elements. You can read more about exterior damp proof paints here
  3. Rendering – Having your house rendered or repairing defects in existing render is also a good way to stop penetrating damp. When carrying out repairs, the wall must be thoroughly dry. You must also repair the defects correctly for this to work properly.
  4. Other repairs. Simple repairs to the external wall of your building can work great. These repairs include:
  • Pointing
  • Replacing damaged bricks
  • Fixing leaks in the roof
  • Re-sealing windows and doors.
  • Repairing damaged guttering that is running water onto the exterior wall

All these methods can help to solve damp issues in a building. The correct option will depend on the type of damp you have.

Are there DIY damp proofing methods?

The good news is most of the above methods can be done with some basic DIY knowledge. A chemical DPC, for example, may sound complicated, but the method of installing it is simple. You just need to drill some holes, and then inject the DPC using a mastic gun. Of course, that is a very simple explanation. But any decent DIY kit will come with detailed instructions. You simply need to read the instructions before drilling the holes and injecting your DPC.

Most of the other damp proofing methods above can be done by the homeowner too. Sealing windows and doors, for example, is a straightforward and quick way of preventing damp.

Jobs working at height such as, repairing guttering and fixing roof leaks can be a little more challenging. It is important that you are careful whilst trying to protect your home from damp.

If any of the methods above seem well out of your comfort zone, do not do them. Get more information, ask for some help or call in the experts. There is no need to risk injury or worse to prevent damp.

Do these DIY damp proofing solutions really work?

All of these DIY damp proofing methods can work very well when applied to the right problem. That is, they work well if they are done correctly. For example, repairing cracks in your render can work well. However, if you miss any cracks or don’t fill them correctly, damp can return. Just like any DIY, if a job is worth doing, it is worth doing right, not twice. These damp proofing solutions will work if they are done correctly.

A prime example of this is the chemical DPC we mentioned earlier. The holes you need to drill, will be between 10-12mm. These will be drilled at 115mm intervals. Don’t worry, no one’s going to get angry at you for drilling holes at 114mm intervals. The chemical DPC will still work. However, if your holes are spaced a metre apart, don’t expect the DPC to work properly.

What we’re saying here, is whatever method you use to damp proof your home, follow advice. Find out how to do it properly. Follow the instructions to the letter. This is the best way of ensuring the damp proofing method you use will work.

There are plenty of detailed articles on this and other websites about each of these damp proofing methods. There are also plenty of explainer videos for most jobs on sites like YouTube.

Also, any damp proofing products you buy will come with detailed instructions. There are plenty of resources available online. The internet can be your friend when it comes to damp proofing your home.

How to ensure the correct diagnosis of damp

Just before we leave you to fix your damp issues, we want to discuss the different types of damp quickly. As you know, there are several types of damp.

The method you use to solve your damp, will depend on the type of damp you have. For example, chemical DPC is a great fix for rising damp, but it will not do anything for penetrating damp.

Likewise, repairing render, or applying exterior damp proof paint will work for penetrating damp, but it won’t for rising damp.

So, firstly you need to know what type of damp you have. From there, you can use some of the methods above to fix the issues and stop damp returning. Finding out what is causing your damp is not usually difficult. We have lots of content on here on that can help you with that. Once you find the correct diagnosis for your damp choosing the best solution is usually quite easy.


Damp proofing the outside of your building is a great way of preventing damp. Also, in many cases this is something you will be able to do yourself. For small jobs you could save a significant amount of money if you identify the problem and find a DIY solution. If you do need any advice about the damp that may be causing your issues, explore our website. Alternatively feel free to send us a message via our contact form here.

We have lots of articles that go into more detail about the various types of damp. You will find the cause to your damp problems, the best treatments and how you can perform them safely. DIY damp prevention and control can be simple if you know the type of damp you have.