How to fix a leaking brick garage?

[kraftburk]

Hi everyone,

I have a single skin brick garage that is built into rock at the rear. When it rains, I get water ingress through a hole where the brick meets the rock - see picture with red circle. Question number 1: How can I fill this hole to make it watertight? Note that I cannot get access via the other side of the wall as this issue is happening below ground level, and under some concrete stairs - see green circles to help orient and see what I mean. Question number 2: Is there anything I can apply to the exposed rock in the garage to 'seal it' / stop it crumbling? And unrelated Question number 3: can you recommend a low-cost way for me make the garage look more finished - right now it is exposed brick, and I'm curious what my options are to make it look a bit nicer. Thanks in advance!

Hole where water comes inRefer to other photo to see where hole is relative to this bit of paper

[EricL]

Hello @kraftburk 

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about your brick wall.

For the brick area that you can access on both sides, I suggest using Selleys 415g Brick And Concrete Sealant, it's a 100% silicone sealant with superior adhesion to concrete and fibre cement surfaces. It also provides a long lasting, flexible and waterproof seal.

However, in regards to the red circle, I'm afraid you'll need to dig the area out as patching it up with any type of material is just a waste of resources. Water coming from the other side of the wall will push any sealant or cover off and if by some chance it does succeed in patching the leak it will divert itself to weakest point in the wall and start leaking there.

If you do manage to dig out that part of the exterior wall, I suggest painting the brick wall with Gripset Betta 1L Waterproofing Membrane Bitumen Rubber. I propose holding off on any renovations until the leak is addressed and repaired.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

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

Eric

[Dave-1]

Afternoon @kraftburk 

Looking at the whiteish discolouration on the brickwork above the hole plus the crack you have between bricks tends to make me think that water has been an issue for a fair while. Since you cant get behind the brickwork to do any remedial action maybe you could work on it from this side.

Do you have a drain or low point along that sandstone wall where the waterpipe comes out?

I am thinking of having a gutter (brick/concrete) at the rear of the garage maybe 5cm off the wall to catch and channel the water elsewhere. Installing a membrane on the front as @EricL has said is a waste of resources as the build up of water pressure wanting to seep through the bricks will push it off. Or cause more settling/shifting of that crack. This would be the easier way to deal with the issue tho you would still get water into the garage.

Going back over your photos makes me to start tho think the long term solution is to remove what is behind the wall to either waterproof or have dry to air of the rear side of the brickwork. It is a huge job I admit but could very well be worth the effort. I had a similar issue with my garage and yep I dug out the rear wall, sealed the low course of brickwork but left it all dry to air. Fixing water ingress issues in garage is my project if you want to have a look.

If you stop water seeping throught /under the wall then hopefully that seperation of bricks will stop.

Dave

[kraftburk]

Thanks @EricL and @Dave-1 @that’s really helpful advice. I suspected there wasn’t much choice but to excavate, and you have convinced me. I will start planning the job and let you know how I get on!