We recently moved house. I noticed some damp soil between downpipe (pictured above) and bricks, which had some spalling (also pictured below). On investigating, it seems like the small space between my garage wall and the neighbour's garage was remaining damp and possibly draining/seeping toward that corner. It was filled with all kinds of builder's rubble and mortar that was staying damp.
Having cut out degraded mortar and repaired the spalling with Dunlop Ardit Rapidset Repair Mortar, I am wondering what to do with the void.
There is some water damage (salts) up first course of bricks inside the gap, but it looks minor.
I have removed rubble to about 5cm below first course of bricks, exposing the tope of the slab slightly.
The plastic waterproof membrane sitting at this level is torn (I think it is coming from under the slab). Because of the concrete in front of the area, there is a step up and so no easy path for water out of the area, except around the front of the bricks and behind the downpipe. Mind you, being so small it doesn't get that much water.
A few options come to mind.
- Add a small roof - would require neighbours agreement to bridge to their house, and plumbing.
- An easier option for DIY woudl be to leave the area open (for airflow) but add some new waterproof membrane, in a slight u shape coming up the first course of bricks, and fill with drainage gravel. Given the low volumes of water, this would collect on the membrane but stay off the away from the sides of concrete/bricks and hopefully evaporate.
- If options 2 seems to retain to too much water and the area really needs draining, to install a french drain and plumb into stormwater. This seems overkill for expense.
On the backside of this area, the width of this gap opens and there is a larger storage area under the back pergola. (Last picture)
Once dampness is solved, I will silicone the expansion gap between wall and concrete.
Any ideas welcome!
