How to Fix Peeling Masonry Paint

Updated Feb 16, 2024 | Posted Jun 7, 2021 | Professional insight, Product Advice | 12 comments

I’ve been a Decorator for the best part of two decades, and in that time I’ve worked on just about every type of job. Exterior paint jobs are one of my favourites, but peeling masonry paint can be a right pain. I thought I’d take the time to explain how to fix peeling masonry paint. I really hope this blog helps you out.

 

Why Does Paint Flake on Render and other Masonry Surfaces?

 

There can be a few reasons, but 9 times out of 10 times it’s down to one, or both of the following issues. Funnily enough, the problem is easily avoided by using paint which is better suited.

 

Moisture

This is an obvious one, but if there is trapped moisture in the render or stonework, it will cause problems. The water tries to escape the render, only to find itself trapped underneath the masonry paint, eventually causing it to lift. This will happen faster during the winter because the water will expand as it freezes and lift larger areas of paint. Moisture is the single most common cause of peeling masonry paint.

Advertisement

Limestone

A lot of cement contains limestone, and cement is a key ingredient of render. This is an issue because lime is slightly alkali and needs to breath. A lot of modern masonry paints such as Dulux Weathershield simply smother the render, resulting in the paint failing over time.

 

How to Fix Peeling Masonry Paint

 

The first thing you must do is remove as much of the existing paint as possible. You can either use a scraper and some elbow grease, or go at it with a power washer. Just be careful not to damage anything else in the process and be safety conscious when working at hight. If you’re using the power washing, give your render a couple of days to dry off before carrying out the next step.

The next thing you need to do is stabilise the surface. For that, I use a product called Zinsser Peel Stop.

There are other stabilising solutions on the market, but Peel Stop is perfect for what you need here. It is a water-based product and as the name suggests, it prevents paint from peeling. Just make sure you adhere to the 2-hour drying time (longer if you can). If you rush things then you’ll create even more problems.

It works by penetrating the masonry, and seeping behind the existing paint. This sticks the edges of the paint down, meaning it is less likely to peel again in the future. It also solidifies any chalky masonry, creating the perfect base.

zinsser peel stop stabilising solution

I normally do my filling at this stage. The Peel Stop helps mask the edges of the remaining paint, but you can also fill round it if you feel it’s going to show once painted. Other than that, I just fill deeper holes and cracks.

My favourite masonry filler is Toupret Murex (now called “Rock Solid Filler”) because it dries rock hard. Some masonry fillers remain porous, which means they can hold onto moisture and potentially cause the paint to fail further down the line. Murex doesn’t do this, so repairs are more likely to last.

Toupret Murex is easy to use and great to mould as you need to. It doesn’t slump either and you can use it on holes of any depth. Just be conscious that it’s difficult to sand once it has cured, so try not to fill proud.

The best filler to fix peeling paint

The Best Paint to Use to Avoid Peeling Masonry Paint in Future

 

It is essential you use a breathable paint product to finish. By using something that allows your render or stonework to breathe, you avoid failure which may otherwise occur due to both moisture or lime.

There are two different masonry paint products I can wholeheartedly recommend. One is probably the best standard masonry paint for this type of job. The other is more expensive, but is probably the best masonry paint on the market. Using either of them means there is less chance of your masonry paint peeling in future.

Advertisement

Wethertex AP77

This is the trade option, but unlike most other trade masonry paints on the market, it is silicone-based. This means the paint film is very breathable and self-cleaning. Wethertex also sticks hard and fast to just about anything and is exceptionally durable once dry. It also remains flexible.

Being a trade product, you’ll also find Wethertex reasonably priced.

A long-lasting masonry paint

Emperor Paint Masonry Paint

This is another silicone-based masonry paint, but it is manufactured to a higher quality than any trade product. It’s very breathable, hydrophobic, self-cleaning, and the paint on any surface is likely to last around 25 years. This is because of the quality of resins within the paint. It is also proven to help with heat retention in your home.

Emperor Paint is expensive though. If you do buy this product, you can use code ‘forum5’ for a discount.

The best breathable masonry paint.

A recent Job we Completed

 

I thought I’d share details of a job we completed recently and explain how we fixed the peeling masonry paint.

how to paint a house and avoid flaking paint

This house was only painted previously a year ago. The homeowner had cleaned everything properly before she painted. She’d also used proper trade products to achieve her desired finish. She was very happy with the way it looked when it was completed, but the paint started peeling within months.

It took two of us a full day to carry out the prep. We scraped all the peeling masonry paint from the render, applied anti-fungal wash, allowed it to dry, then coated Zinsser Peel Stop over the whole lot.

We didn’t need to do any filling because apart from the failing paint, the walls were in good nick. Peel Stop was enough to hide the edges of the failed paint. We then applied two coats of Wethertex AP77 (which is a fantastic paint).

The house looks like new now, and I gave the client a 2-year guarantee. However, I’m confident that the paint will last a lot longer.

Advertisement

Tools you Need to Fix Peeling Masonry Paint

 

Very quickly, I thought I’d mention the tools you will need to fix flaky masonry paint. I’ll link to the products where I can make things nice and easy.

Access equipment – There’s no point in me linking for this one. If your flaky masonry paint is high up, you will need a ladder, scaffolding, or a cherry picker to reach it. You can buy any of these items, but unless you’re going to use it on a regular basis, you’re probably better hiring it. Just have a quick Google search and phone your local hire shop. They’ll even drop it off and pick it up for you.

Scraper – This is an obvious one, but you will need a scraper to remove flaking masonry paint. Click here to see online prices.

Paint roller – Any long-pile 9-inch roller on a pole is perfect for applying both Zinsser Peel Stop and masonry paint. The best roller for this type of job is the Purdy Colossus. You’ll find it holds and distributes loads of material, which makes working at hight a lot easier because you don’t need to load it every 2 seconds. It’ll also coat the surface of rough textured masonry. Click here to see online prices.

Paintbrush – There are a couple of different paintbrushes I could recommend for applying masonry paint. Stay away from those big floppy “masonry brushes” in DIY shops because they’re very difficult to use. If you want a cheap brush that’s up to the task, then go for Hamilton Prestige. Click here for online prices.

If you want the best brush available for applying masonry paint, and you want something you can wash out and carry on using it for years to come, then go for the Purdy Monarch Elite XL. You pay more, but it’s a brilliant brush. Click here to see online prices.

Advertisement

FAQs

 

Can I paint over peeling exterior paint?

The issue with painting over peeling paint is that no matter what paint system you use, if the existing paint carries on peeling, then both will fail. We recommend removing as much of the peeling paint as possible, applying a coat of Zinsser Peel Stop, and then repainting with a breathable product.

 

Can I paint over old masonry paint?

Providing your existing paint is sound, then painting over it is not an issue. Just ensure it’s clean before you start painting and use a fungicidal wash if required. Prepping exterior walls is important.

 

What is the lifespan of masonry paint?

Cheap masonry paint doesn’t tend to last very long at all. Even some of the ones that claim to have a “15-year lifespan” can start to lose their colour, go mouldy, or start to peel. We recommend using Emperor Paints if budget allows, or Wethertex if you need a cheaper alternative.

 

Final Thoughts

 

I hope that helps. Fixing peeling masonry paint is nothing complicated. You just need to understand what’s causing the problem, get your preparation right, then use the correct products to avoid issues in the future.

The best advice I can give you is use breathable paint products to avoid trapping moisture.

How to Fix Peeling Masonry Paint – by Mike Gregory

Updated Feb 16, 2024 | Posted Jun 7, 2021 | 12 comments

Related articles

12 Comments

  1. Dan lynch

    Peel stop for interior not exterior it says it on the tin iv been painting for 30 years bulls eye I use

    Reply
    • Mark

      Peelstop is for both interior and exterior, it’s clearly stated on the tin and Zinsser website.

      Reply
    • Richard KIlle

      Peel Stop® is a clear, flexible bridging sealer for surfaces where peeling, flaking, dusting or chalking is a problem. Interior and exterior. Forms a breathable membrane over faulted substrates.

      Reply
  2. Richard KIlle

    Peel Stop® is a clear, flexible bridging sealer for surfaces where peeling, flaking, dusting or chalking is a problem. Interior and exterior. Forms a breathable membrane over faulted substrates.

    Reply
  3. Chris

    Great article, clear and concise. Cheers Mike!

    Reply
  4. stuart mayo

    Hi, many thanks for this, very useful. Any advise on how to overcome the difference in texture /depth where the peeling paint has been removed vs the area that still has pain on it? An extra coat of new pain on the bare area?

    Reply
    • graham Colvin

      Stuart mayo..
      after removing an area of paint, peel stop as sated will help glue down edges of transitional areas.. then feather the edges with Toupret murex (rock hard filler) with a finishing trowel or similar for an invisable smoothing repair, an extra coat of peel stop if bare patches are not as shiny as surrounding wall will help overall finish and prevent flashing through paint

      Reply
  5. Gill Skelton

    Thank you. I painted mine 5 years ago and it’s bubbling where water is getting trapped but only on the part where it gets all the weather. I’m going to try what you say about the sealer but will probably repaint with sandtex so it marches the colour of the rest as I will only need to do the west facing wall, the corner going round to the south face for about 7 foot in. I am hoping this works as I am on a budget. 🤞

    Reply
  6. Ghulam

    Hi,I’m in the process of painting my rendering wall in the allyway as I’m getting a lot of paint peeling from inside the house allyway side even though I just had my internal walls freshly plastered.

    Reply
  7. dave goodwin

    The owner did everything right according to you. She cleaned and prepped and used the correct products. Therefore you shhould not repeat the process she did without all both of you analising the cause of why hers failed so fast. You say “Fixing peeling masonry paint is nothing complicated. You just need to understand what’s causing the problem”
    but you do not practise what you preached.
    By repeating all that work without diagnosing the problem you risk wasring a lot of money for your client.
    Possible overlooked causes:
    underlying chemicals in masonry impeding good bonding, effects from environment, temperature differentials, etc. All these should be analised instead of re-doing it without knowing.

    Reply
  8. Larry Ryan

    So you apply the Peel Stop BEFORE repairing cracks etc? Then the top coat?

    Reply
    • Mike Cupit

      Yes. You need the Peel Stop to penetrate the surface and stick the edges of the paint down. If you make repairs and your filler is powdery, then you might prime the filler also, but you generally don’t need to.

      Reply

Submit a Comment

Your email address will not be published. Required fields are marked *