Crumbly wall and how do I fix it?

javiercarrillo

I am not quite sure how to describe it so apologies in advance if I use bad terminology.

I just noticed that there’s a crumbly area at the bottom of the external wall in my garage. The material feels like rocky like concrete but somehow softer (maybe it’s insulation?).

Does anyone know what type of material this is and what might be causing the crumbling? (Garage is about 12 years old).

Also, any advice on how to fix it? (It’s my first house so I’m new to this sort of things).

thanks!

10-10-20

That black painted section is the bottom of the external render and that small sheet of black plastic in there is the DPC (damp proof course). The render keeps the water off the concrete blocks inside the wall and the DPC stops the damp from coming up from the foundations or the lowest parts of the wall.

Render does have a habit of failing in this way, it often weakens at the lowest part of the wall from water action as the ground levels can move slightly and cause cracks which cause expansion/contraction and failure.

The fix here would be to repair that small patch, but to be honest it's a bit of a tricky job unless you're familiar with working with cement render and finishing it off. I'd be inclined to leave it as it is for the moment and look at repairing it closer to the time when you might be repainting.