How to stop bricks from crumbling?

[LinN1]

Hello!

I’m renovating a 1959 fibro house, and the brickwork at the front is crumbling. Not knowing how active the crumbling was, I recently gave it a good clean and painted with lime wash. Unfortunately the brick continues to crumble and now it looks worse than before.

I know the drainage around the house is not great and will be installing French drains shortly. Although I find it interesting how the bottom bricks are showing no signs of water damage, but the ones that do are way above ground.

How do I stop the crumbling or prevent it from getting worse?

Once drainage is sorted I plan on filling in/repointing, lime wash once again, and then ultimately render in the future.

Any help would be much appreciated!

[EricL]

Hello @LinN1 

Looking at the photos it appears to be some form of plaster or mortar that was applied to the surface of the brick in order to give it a white appearance. 

However, I believe that water from behind the brick wall has been slowly contaminating this material and making it deteriorate. Upon reaching its saturation point it begins to crumble and fall off. Does the surface feel cold and wet? Do the crumbled pieces feel wet between your fingers? This would be a strong indicator that moisture has travelled from the back of the brick to the front of this material.

Unfortunately, if that is the case, I'm afraid that there is no slowing it down. Even if we applied a sealer to the front of this white material, the portion where it meets the brick face will be the point of failure.

I suggest considering removing this material in front of your brick wall and painting the brick wall instead.

Let me call on our experienced members @Adam_W, @TedBear and @JoeAzza for their recommendation.

If you have any other questions we can help with, please let us know.

Eric

[LinN1]

Hi Eric,

Thank you very much for your response.

The white is the lime wash I mentioned. I didn’t want to paint the bricks with a plastic paint in case there was a moisture problem. The brick wall looked like this before with the crumbling indents, I just cleaned it off and lime washed it white as the red brick stood out as a sore thumb against the white weatherboard. The problem is that it continues to crumble hence the lime wash comes off exposing the red brick.

The crumbling feels sort of dry and dusty, no chunks are coming off.

Over time I think the crumbling is quite slow, but because it’s lime washed white it’s very obvious when it happens.

I could probably keep lime washing it once every fortnight and it would look ok, but that’s not a long term solution and also wouldn’t allow me to render in the future.

I hope this clarifies further 🙂

[LinN1]

A couple of photos showing what the brick facade looked like before I painted it white using lime wash, and just after painting. As you can see, the crumbling bricks causing the ugly indents were already there.

[EricL]

Hello @LinN1 

Thank you for the clarification, it is very peculiar that the lime wash on your brick wall is falling off. Limewash is often an excellent cover for brick surfaces and usually last years before you need to apply another coat.

One possible product I can suggest is Crommelin 1L Natural Finish Penetrating Sealer And Water Repellent. As the name suggest it is a penetrating sealer that should bind the surface of the limewash and prevent it from falling off. 

I also propose trying it on the difficult to paint surfaces, before applying a new coat of limewash in that area.  

If it continues to degrade, the brick wall might need to be redone and properly sealed. Once it's properly sealed you can then apply the limewash.

Eric