Best Damp Proofing Paint For Interior Walls

The DIY Fix is reader supported. When you buy after clicking a link on our site, we may earn an affiliate commission.

Damp is a big issue for many homeowners. The good news is, when you discover it, you can rest assured that there plenty of solutions.

From damp proof tanking and membranes, to damp proof courses, and damp proof paints. There is a wide range of damp treatments out there. Some of these are easy enough to do as a DIY project and for some you will need professional help.

In a Rush?If you don’t have much time use the link below to quickly find our favourite damp proof paint and read hundreds of reviews on Amazon.Click here to view our top pick >> Ronseal One Coat Damp Seal

When any kind of damp rears its ugly head. It’s never convenient. It can also be costly – but even if the damp has developed into a bigger problem, at least you know it can be sorted. However, prevention is better than the cure and more and more people these days are thinking in a proactive way when it comes to damp.

Damp isn’t just about treatment, it’s also about prevention and protection – and this is where damp proofing paint for interior walls comes in.

So, let’s look at the pros and cons of damp proofing paint. This will include, what it can, what it can’t do – and some of the most popular damp proofing paints that are on the market. This will help you to make an informed decision about whether damp proofing paint for interior walls is an appropriate course of action for your property – and what brand might be the best to buy for you.

Damp proof paint – the pros and cons

The great news is that there really aren’t any ‘cons’ as such. However, you should fully understand that damp proof paint is not a damp cure-all. The root cause of the damp problem needs to be treated and rectified before damp proofing paint is applied.

You may use damp proof paint after a more serious damp proofing job has been completed. For example after a new damp proof course has been inserted.

Damp proof paint can be particularly useful for covering up black mould spots in rooms that suffer with minor condensation issues, such as bathrooms or kitchens. But this may only be a good solution where there are small issue with condensation.

Again in more serious cases you will still need to address the cause of the condensation in a particular room or right across the property.

So, with this in mind, you might be thinking: “Well, what does damp proof paint actually do then? Is there any point?

What damp proof paint does do, and it can do it very well, is prevent and protect against damp resurfacing. When you have suffered with more serious damp issues such as penetrating damp or rising damp, internal walls will have been affected by damp.

Damp proof paint is the logical next step once these larger issues are repaired. It works by acting as an extra level of protection for the future, as well as tidying up a damaged surface area.

Damp proof paint is also easy to maintain. It’s obviously more advanced than a conventional wall paint, but it is essentially a paint. Therefore, once it’s fully dry it can be washed, wiped and re-applied in the way that you could do with an ordinary matt or emulsion.

Damp proof paint is an effective way of making a home look more attractive. It covers up unsightly damp patches and greatly improves the cosmetic appearance. But it’s doubly effective because it damp proofs too. Finally, it’s cost-effective as well.

As with any type of home improvement product, buying a low budget range product is probably not the wisest move. It’s often a false economy to choose the cheapest option. But that doesn’t mean that you necessarily have to plump for the most expensive either.

Applied properly, in suitable conditions damp proofing paint for interior walls can really protect your home against damp. Let’s take a look at the products that are available.

Ronseal One Coat Damp Seal

Our number one choice for internal damp proof paint is One Coat Damp Seal by Ronseal. It can be used in a variety situations including as a finished coat paint. Alternatively, it is suitable to be painted or wallpapered over.

It is a very easy-to-use product and offers a nice smooth application. We found this to be better than many other products which seemed stiffer and more difficult to apply.

It can be used on both bare and previously painted surfaces and offers a good coverage of 5m² per litre.

As with all damp proofing paints for internal walls, it is important to carefully prepare surfaces before applying the paint. Any loose or flaking paint should be scraped and sanded off.

Ronseal One Coat Damp Seal works well on most wall surface as long as they are clean. It is even highly effective on quite damp surfaces, just as long as they are not dripping wet. The best advice would still always be to allow the walls to dry as much as possible though.

Ronseal One Coat Damp Seal can be applied with either a roller or a brush and is particularly good for covering up isolated patches of damp. You should always paint at least 30cm around the affected area. The product will be touch dry in about 2 hours in well ventilated space.

You can learn more about Ronseal One Coat paint and read customer reviews on Amazon by clicking here

Thompson One Coat Damp Seal

This is one of the many examples of a damp proofing paint for interior walls that is primarily used to produce a primed surface ready for final decoration.

It works as an interior seal. The result is a breathable membrane that enables trapped moisture to evaporate. This ensures that the tell-tale signs of damp, such as flaky paint and peeling wallpaper, do not occur.

It’s at the cheaper end of the price range and does a pretty good job overall. It can be used on all interior walls and ceilings and produces an impressive coverage of approximately 5m² per litre -although tins are generally 750ml in size. Full coverage can normally be achieved in one coat.

The one big word of warning with Thompson One Coat Damp Seal would be in terms of its recommended drying time. It claims just 4 hours on the tin. However, users have reported leaving a full 24 hours before applying a coat of emulsion.

With that said, it is a highly rated product, at a fair price and that is why it made the second spot on our list. Not only does it do a good job, but it is also very affordable.

You can learn more about Thompsons one coat damp seal and read customer reviews on Amazon by clicking here

Technoseal Damp Proof Paint

This is an all-purpose product. It can be used under tiling and for floors as well as being used as a standard damp proofing paint for internal walls.

It’s the multi-use versatility of Technoseal Damp Proof Paint that will appeal too many. It can be applied to a range of surfaces by roller, brush or spray.

Users report that it can be a bit tricky to apply. It can be difficult to apply evenly and achieve the necessary 0.6mm full coverage required. However, the end results are good. It works particularly well in bathrooms to cover isolated damp patches.

You can learn more about Technoseal damp proof paint and read customer reviews on Amazon by clicking here

Johnstone’s Damp Proof Paint

Johnstone’s damp proof paint range is one of the most popular on the market. It’s pricier than many but is a versatile product that works well for a variety of situations.

Whether it’s painting after re plastering or condensation in bathrooms, this stuff does the trick. It has the advantage that you can leave a coat as the final finish, if you wish – or apply matt and emulsion on top.

The gripes that some users have with this damp proof paint, is that coverage isn’t as good as the product claims. It is not uncommon that more coats are needed. Also, many people pass comment about its unpleasant smell! Other than that though, this product is reliable and should give you good results.

You can learn more about Technoseal damp proof paint and read customer reviews on Amazon by clicking here

Perma-Seal Damp Proof Paint 

This is a damp proofing paint for internal walls that claims to be able to do pretty much anything.

It can be used on walls, ceilings and even floors including timber (to provide a damp proof membrane). Often with such products you begin to wonder if it’s a ‘Jack of all trades, master of none’ but user reviews of the product are overwhelmingly positive.

It’s versatility makes Perma-Seal Damp Proof Paint highly useful in large scale renovation work as it can be used in all the following cases:

  • Waterproofing timber
  • Providing a damp proof membrane to floors
  • Offering secondary protection under tiled areas
  • For walls – both under a render as a waterproofing layer, or as a paint to cover up damp stains.

Certainly, if you do have call for various uses, this product would be a good choice. It also boasts a quick drying time too – only an hour or so for the first coat and 24 hours for the second. As it dries as a slightly different colour, it’s easier to achieve full coverage on a second coat.

You can learn more about Perma-seal damp proof paint and read customer reviews on Amazon by clicking here


Choosing a damp proofing paint for internal walls is really all about weighing up the various options with your particular needs. Of the products listed here, there certainly isn’t a stand-out winner or loser. One coat damp seal is our preferred choice. However, they all do perfectly adequate jobs when applied in the right situations.