Advice on spalling

[huwy123]

Hi there,
I've noticed some spalling on the corner of my 1950s house and was hoping for some advice - namely should I just patch this up (and seal?), or could there be an issue here that needs investigating?
This is the corner of my integrated garage. The block paving was done about 4.5 years ago.
Happy to provide more info/pictures if needed.
Thanks in advice for any advice, it really is appreciated
Huw

 

[DiyNutJob]

Probably caused by surface water. Having a slope on the paving to move water away from wall might help. Only guessing here.

 

[DAZB]

Water bouncing back onto the wall is very likely the main cause and ideally you would have a drainage channel such as an Aco drain or you could cut a channel by marking a 100mm border, removing the blocks and cutting them and replace them while filling the newly made channel with chippings or decorative gravel etc which will help.

 

[^woody^]

Coat it generously with a silicone water repellant - eg Thompsons, and see how you go. If it arrests further spalling, remember to re-coat every five years or so.

Treat the lichen first with a fungicidal wash such as Patio Clear.

 

[huwy123]

Thanks all. I have some wet and forget so will use that. Then maybe try some brick repair and waterproofer

 

[Ivor Windybottom]

Looks like the drain may be occasionally overflowing. Might be better to directly couple the downpipe into the gully.

Also seal between the gully and wall within the drain.

At the very least fit a leaf guard.

 

[Ivor Windybottom]

By the way the gully suggestion was relevant, I was suggesting it may be wetting the ground, which is getting wicked up by the bricks then freezing, popping them.

But looking again at your photos... as suggested by DiyNutJob, is there a gradient on the paving away from the bricks? If not then there's no easy solution, they need pulling up and re-laying. I'd put a 100mm boundary of 20mm gravel between the building and paving as also suggested above, at least 3 courses deep. Gravel is almost as good as fresh air, and it doesn't splash anything like as much as paving.

I'd also leave it a while before tipping the gravel in, check it's not filling with water when it rains. If it is there's more work to do.

 

[huwy123]

Thanks. I'd think the gradient is ok, I've taken a picture from behind the drain as you can see the slope against the wall.

I'm thinking water splashing (made worse by dropped leaves blocking the drain) is the likely cause. Will look at a cover.

 

[Ivor Windybottom]

Definitely looks like a decent gradient. When we next get some decent weather and it gets dry, probably next year, it's worth squirting some sealant around where the drain meets the surroundings. I found ours were overshooting the drain in heavy rain and vanishing down the side of it. I really don't like the idea of the shoe on the end of the pipe, it's well worth grabbing an umbrella and going for a walk the next time it rains heavily, see what's actually going on.

I got a bit mad inventor and bought plastic grids that have a pipe cutout, got rid of the old shoes off the ends then used a couple of couplers to pipe directly in. Now the leaves don't make the slightest difference.

See attached photo showing one of my downpipes and sealant. Belt and braces!

Edit: Just saw yours doesn't even have a shoe, so it's basically pointing at the gap between the drain and wall. Change this!

 

[huwy123]

I see what you mean - the right angle of the shoe is going to reduce splashing. Will look into. Guess I will need to shorten the drain pipe. Thanks for the excellent advice

 

[Ivor Windybottom]

Yes, but they only create a different problem - that if it rains heavily they fire right across the drain to the other side. Mine (shown above) has a concrete surround but it's freestanding, so the overshoot could run straight under it.

Mine now work perfectly, light or heavy rain and however many leaves are blowing around.

Most of the plastic grids have an optional cutout marked on them, I just cut it out then popped the coupler through, it even holds it up. Another coupler, then the chopped off shoe above that (could have used a third coupler).