Retaining wall frost damage to bricks All manner of questions and solutions to problems and issues surrounding the subject of brickwork, blockwork and stonework

[Diysalad]

Hi Everyone,

First post here. I have a garden retaining wall which holds back a lawn and some flower beds. The soil is very heavy clay and saturates through most of the winter. The retaining wall is about 4 bricks high and experiencing rapid frost damage in winter. My first thought was likely improper drainage behind the retaining wall. So i decided to investigate what was there. It was loosely backfilled with shingle, but clay has migrated into the shingle mix and just blocked the drainage holes. So i dug out the back of the retaining wall and installed a french drain. Geotex fabric material encapsulating the shingle to prevent migration of the clay. This seems to be working in that the drainage is much improved and the soil directly behind the retaining wall is much drier. However the bricks continue to degrade and i think now they are already frost damaged, water entering from top is just saturating the brick and you can see them darken in winter.

I guess the problem is likely the bricks are just poor quality porus bricks combined with poor drainage and heavy clay soil. My question is, can i do anything with this? My thoughts were to seal the brickwork with a sealant, and then see if it arrests the damage. Then maybe render and paint it, but then is a render going to stick to the brickwork? If i just render it, my concerns is the brickwork will continue to deteriorate and my effort would be wasted. Is there a way i can seal it and then render if after? Am i wasting my time and the wall is just screwed? Or is there something else i should be doing.

https://youtu.be/myf2H1mKqdY

Here is a video i made so you can see what I’m talking about.

Cheers

Richard

[stoneyboy]

Hi diysalad,
Great video clearly demonstrates the problem.
Cap the wall with concrete capping stones
OR knock off the soldier course and replace with solid engineering bricks.
Regards S.

[George441]

Thanks for your video. I agree with you mainly it happens for poor quality bricks. This can also happen if the walls are built long ago. You may try a plaster or you may follow as stoneyboy said.

[George441]

Thanks for your video. I agree with you mainly it happens for poor quality bricks. This can also happen if the walls are built long ago. You may try a plaster or you may follow as stoneyboy said.

[Diysalad]

Thanks All.

So what about render or do you think that approach is not a good idea?

Like the idea of capping with stones and replacing not bricks with engineering.

When you say ‘plaster’ what sort of plaster would be appropriate. I dont know much about this stuff.

Thanks very much

[stoneyboy]

Hi diysalad,
Rendering a retaining wall is a waste of time and money, in a few years the render will blow off in patches.
Stick with capping the wall.
Regards S.