How to fill gap around downpipe and double brick wall?

[RevH]

There is a gap between the down pipe and the brickwork on the outside of my building. It is a double brick building and you can see the inner brick wall through the gap. We have big issues with moisture on the corresponding inside wall and I suspect this gap might be a contributing factor. Would expanding foam be a suitable option?

  

[EricL]

Hello @RevH 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about the gap near your downpipe.

I propose removing the downpipe and covering the gap with Crommelin 1L Exterior Grade Brushable Waterproofer - 1L to seal the gap from water. I then suggest re-installing the downpipe and using Poly 750g Expanding Foam Aerosol Can to fill the gap. Once the foam has cured you can then cut the excess off with a Craftright 18mm Snap Off Knife. 

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

If you need further assistance, please let us know.

Eric

[Dave-1]

Good Afternoon @RevH 

I would definently go the route that @EricL has suggested. With moisture issues that you mention my first thought is it leaking behind the downpipe and getting inside that way. With the solution @EricL has suggested it takes the issue away from being a concern as there will be waterproofing in that gap. I would be tempted to put a cover strip over the whole lot if you dont like the look but think it would show more so.

Dave

[RevH]

Thank you both @Dave-1  and @EricL. The building is a larger block of units with the same style of inbuilt down pipe on other exterior walls. However, no other tenants have reported having the same issue with condensation on their interior walls. I don't know for sure it is related to the down pipe, but the only spot I have condensation on an inside wall is exactly where this pipe is. 

I would love a solution that didn't involve major works through the body corporate, but maybe I am being too optimistic!

[Dave-1]

Afternoon @RevH 

I would have a very close look at behind the gutter then, especially from up the top of a ladder (while being safe) after rain. If its wet/damp then I would definently bring it up with the body corporate as its the responsibility for outside things for sure. The wetness espeially at night could cool the brickwork like a wick and then condenstaion could be able to form more rdibly on the inside is where my thoughts are trying to describe.

Dave

[EricL]

Hello @RevH 

Thanks for adding that bit of extra information. I agree with @Dave-1's suggestion and observe the downpipe carefully and see if trapped moisture is making its way through the brick. If you take photos or videos of the condensation happening, you'll have solid proof that something is occurring at the front that's causing water to pass through the brick wall. 

Eric