[SamT]

Agree with the above, and on the point of expansion, some external Frame sealant, between sill and brick should give you that flexible joint to allow for expansion.

[Paul B]

Yeh if that was me I’d cut a brick down and mortar it in as neat as possible to match in with the joint lines, then mastic remaining gaps between the sill and brick (presumably there’s already mastic down between the frame and brick? so can match it with that colour).

This. That corner of mortar was always going to crack off.

[nic mullin]

Thanks all, much appreciated. I’ll go with cutting brick pieces to shape and mortar to brick, sealant to sill as suggested as plan A.

While I’ve got the mortar out and everything cleaned up I think I’ll still have a good look and see if trimming the sill looks viable though - I‘m pretty poor at brickwork so there’s a reasonable chance I can do a neater job of cutting the sill and working with square brick pieces than leaving the sill as-is and cutting the bricks. I think I also stand a better chance of keeping all my fingers that way - I’m a bit of a liability with a grinder 

[SamT]

The sill should cut fairly easily, a fine hacksaw blade should do it, and a craft knife to trim the burrs. The little 'end cap' which is usually glued in, might be able to be re-used and re-inserted into the now open sill, if its not been glued in well.

[nic mullin]

Thanks Sam, I hadn't though about the end caps. They'll be crucial as as I won't have a surface to seal against the brick without them.  I'd imagine they'll be pretty brittle and it'll be hard to find replacements if when I inevitably I break them trying to get them out.

[James Malloch]

Has anyone ever had a resin floor removed? Looks like it would be a pain in the arse…

Edit - I think it’s called Pebble Epoxy and it seems to be used on driveways and garages. Here they decided to put it in the kitchen and dining room…

[webbo]

They also use it in bathrooms. How hard to remove might depend on what it’s laid on. If it’s on concrete it might be a nightmare but if it’s laid on plywood it might not be too hard get up. You would get down to plywood and rip them both up.

[James Malloch]

They also use it in bathrooms. How hard to remove might depend on what it’s laid on. If it’s on concrete it might be a nightmare but if it’s laid on plywood it might not be too hard get up. You would get down to plywood and rip them both up.

Cheers - I didn’t find any companies offering it internally. But that’s useful to know, thanks. You can get under the floorboards via a crawl space so might be able to work out what it’s laid on from underneath.

Hadn’t realised it could be put on ply - I’ve only seen concrete mentioned.

Short term we might try to lay some Lino over if it looks like a pain to take it up.

[spidermonkey09]

Why not just vinyl over it and save yourself the graft? Sounds like a pig of a job with no real payoff?

[James Malloch]

Wondering if anyone has any thoughts on a leaking retaining wall…

As per diagram below we are looking at a house which has a garage/celler built into a hillside. It’s at the bottom of the garden so not close/joined to the house and has been there for about 10 years and all seems pretty solid (had planning permission to put in after an old one burnt down).

Summerhouse/veranda is on top which keeps it mainly weather proof from above).

Front (on left of diagram) is fully exposed. The back wall (on the right) is fully underground against the garden.

The sidewalls are fully covered at the back but go to being uncovered by soil at the front (left side of image).

It’s got a leak where I’ve marked and has water coming through the wall.

I assume that sealing it from the inside is possible but would be a temporary fix.

Best option would be to excavate it and fully reproof it somehow. But the back wall is about 3.5m wide and 2.5m tall so it’s a hell of a lot of soil to move (which may impact the integrity of the wall too?).

Does anyone have any idea how big a job that might be (likely for a professional)? Or anything that we should consider?

What kind of person would we even be looking for to do the work? 

Would be great to have a board in it but there’s no way to keep it dry in there at the moment….

If anyone needs architectural diagrams then I’m happy to help..



Additional photo. Blue line shows approx location of the cellar.

[Paul B]

Does the retaining wall have any drainage? Has the drainage being rodded recently? I would start here. If someone hasn't installed any drainage then they're a pillock.

PU grouting is one method of plugging such leaks. Other options would be to accept water is very persistent and find a way of dealing with the leak/water.

I'd also be having a damn good stomp around the ground above and look for any depressions or soft areas. Water like this transports fine material, gradually at first but with increasing speed and you can end up losing material quite readily (internal erosion). It's probably not the biggest concern from what you've described.

Remember that even a 1mm slither of water at the back of a retaining wall is the same as having a lake behind it in terms of the pressure exerted on the wall. If you did seal a mid height leak and end up retaining water to ground level this would potentially be detriment against the existing condition.

Grouting will obviously push the water elsewhere.

(STD. DISCLAIMER: please don't take ANY of this as a professional recommendation/or otherwise).

[tomtom]

A drain (plastic pipe with holes in it to collect water) about 1m down (ish - +/- 30 cm) across the back of the garage then bending 90 degrees to emerge from the soil slope next to the garage might help. Easiest way would be a bloke with a minidigger (£300-500 a day).. You'd need a load of crushed rock/gravel to stick on top of the pipe before putting the soil back on top.

Or tank the garage - with a drain running out of the garage door.
Or cut a small drainage runnel around the perimeter of the garage floor and let it drain out the front.

[James Malloch]

Does the retaining wall have any drainage? Has the drainage being rodded recently? I would start here. If someone hasn't installed any drainage then they're a pillock.

PU grouting is one method of plugging such leaks. Other options would be to accept water is very persistent and find a way of dealing with the leak/water.

I'd also be having a damn good stomp around the ground above and look for any depressions or soft areas. Water like this transports fine material, gradually at first but with increasing speed and you can end up losing material quite readily (internal erosion). It's probably not the biggest concern from what you've described.

Remember that even a 1mm slither of water at the back of a retaining wall is the same as having a lake behind it in terms of the pressure exerted on the wall. If you did seal a mid height leak and end up retaining water to ground level this would potentially be detriment against the existing condition.

Grouting will obviously push the water elsewhere.

(STD. DISCLAIMER: please don't take ANY of this as a professional recommendation/or otherwise).

Thanks, Paul. I’m unsure about drainage but I’ll ask (or get someone out to check). It’s a house we are negotiating a final price on and it’s the owners children dealing with it as the owner has gone into care, so I suspect the answer will be “we’re not sure, sorry”.

Would the drainage for such a wall likely be something external (like TT has described) or something which drains through the wall (into garage/cellar). If it’s external we might be able to snoop around and look as it would drain onto the footpath at the front of the space.

PU grouting could be a good option assuming the integrity of the wall is fine. We’re not sure how it’s actually built (and to what standard). There’s a photo of the inside below. Most of the space is actually really dry (i.e. other 3 walls are spotless). The top of the wall has some leaks but that’s due to a bad design letting water in which we would change. It’s the bit at the bottom of the ladder which is the main concern for us as it was like a little river the other day.

We assume the wall is made from blocks as it looks too coursed to be poured concrete (but I don’t actually know).

A drain (plastic pipe with holes in it to collect water) about 1m down (ish - +/- 30 cm) across the back of the garage then bending 90 degrees to emerge from the soil slope next to the garage might help. Easiest way would be a bloke with a minidigger (£300-500 a day).. You'd need a load of crushed rock/gravel to stick on top of the pipe before putting the soil back on top.

Or tank the garage - with a drain running out of the garage door.
Or cut a small drainage runnel around the perimeter of the garage floor and let it drain out the front.

Is tanking basically cleaning and painting (but not with paint) to provide a new waterproof layer?
Drainage channels could work well too.

If we could get it sorted for, say, £2k then I’d be pretty happy with that. Assuming the wall is structurally sound etc. Even if it meant keeping on top of a bit of water every now and then. The floor is raised so everything is actually dry in there (just some bits have suffered from damp. But the main concern would be the foam under the board as it could get really grim really quickly.

The house has had a big extension, the guy was hugely into his gardening and maintenance. Boiler has just been replaced, the kitchen is an expensive one, there’s thousands and thousands of (ugly) fitted furniture. So, I feel like he was the kind of person who wouldn’t have skimped on getting this built which gives me some confidence that the wall was okay and it is (hopefully) just a recent issue which hasn’t been sorted as he went into care last year.

But it is all built up above a public footpath so we’re also quite cautious that we don’t want it to collapse!

[Paul B]

Yes, typically you'd lay drainage at the rear toe of the wall, as Tom describes, the construction would be half perforated pipe (perfs up), granular surround and some geotextile to stop the fines moving from the retained fill into the voids in the granular fill. If it's there it'll need to come out somewhere. As I said, have a stomp about above and see how wet things are (and if there's any evidence of the granular material near the surface).

If you're not sure how it's built (and you REALLY want to know) then a couple of trial holes behind the wall might give you a clue but it's not uncommon for people to build walls that are thinner at the top. You could also try sinking a long SDS drill through the back at various heights if you're confident there aren't any services although I'm not sure I'd let a prospective buyer loose drilling things prior to exchange! This is loosely what we do with masonry bridge abutments when assessing them with the bridge deck/beams removed but the SDS drill bit is usually an 80-100mm core instead.

[James Malloch]

Yes, typically you'd lay drainage at the rear toe of the wall, as Tom describes, the construction would be half perforated pipe (perfs up), granular surround and some geotextile to stop the fines moving from the retained fill into the voids in the granular fill. If it's there it'll need to come out somewhere. As I said, have a stomp about above and see how wet things are (and if there's any evidence of the granular material near the surface).

If you're not sure how it's built (and you REALLY want to know) then a couple of trial holes behind the wall might give you a clue but it's not uncommon for people to build walls that are thinner at the top. You could also try sinking a long SDS drill through the back at various heights if you're confident there aren't any services although I'm not sure I'd let a prospective buyer loose drilling things prior to exchange! This is loosely what we do with masonry bridge abutments when assessing them with the bridge deck/beams removed but the SDS drill bit is usually an 80-100mm core instead.

Thanks again!

So (assuming the wall is built properly) the worst case would likely be excavating, installing proper drainage at the toe of the wall, and filling it in properly. Along with perhaps PU Grouting the known weaknesses and then cleaning/repainting?

If we wanted to get a specific survey for someone to come and check this out, do you know the type of company/contractor we would need to get in contact with? I think a standard building survey wouldn’t cover this?

[Paul B]

I think your best bet, if you're concerned would be to get a one-man Civils company with a good reputation to site and ask them how they'd achieve what you want (getting rid of the leak) and the method they'd use.

If it makes you feel any better, I've got zero idea of how my garage is built and it retains fill on two sides and it doesn't lose me any sleep.

[SamT]

I'd maybe just look at tanking first.  Sure, drainage will help, and is probably a bit of a diy job, but you'll still have damp walls.

Google "tanking a cellar" for ideas.  Its lining the walls with a water proof membrane,  having a channel at the bottom to take the water way, then lining with a nice new plasterboard wall in front (you wont really need to insulate it unless you want it all gucci warm/heated).

[Paul B]

I'd maybe just look at tanking first.  Sure, drainage will help, and is probably a bit of a diy job, but you'll still have damp walls.

Fair comment, and not something I know much about.

[petejh]

I'm in the process of planning a french drain (what TT and Paul are talking about) at my new place - I'm building a timber garage in the back field and want the ground around it to drain better than currently before I lay a concrete slab. Cost involves one man plus mini-digger (could be a woman but what are the chances). My neighbor apparently knows a local farmer who'll do it for £140 per day inc. machine. 1-2 days to dig the 2 trenches I require but it's a fairly large area. Perf pipe. Aggregate. Some solid pipe for the outflow part, a few connections, maybe a point catch drain. I'll be doing it myself except the mini-digger.

Plenty of youtube vids of french drainage if you're curious to see some interesting French Drain beef - of course, this is social media-world - between the drainage contractors of Florida (sandy soil) versus North Carolina (clay soil)  on type of pipe, geofabric v non-geo fabric, and grass cover versus exposed aggregate. I like the 2nd vid below, he's like the Tiger King of drainage.

[Paul B]

Plenty of youtube vids of french drainage if you're curious to see some interesting French Drain beef

I'm not going to lie, a trigger warning would've been nice 

[tomtom]

We did an ‘on the cheap’ half tanking job on one cellar room. We were fortunate as the house is built on loose sand so free draining*. This involved ripping up the existing concrete floor. Laying a new one with a damp membrane (plastic sheet) under it  then running up the bottom 10-20cm of the wall. 10cm of kings pan was also out under the concrete (above the membrane obvs). Then for the damp walls we used a membrane (looks like bubble wrap but is harder) with special sealed plugs that you use to fix it to the walls. The membrane then goes inside (wall side) of the floor sheet so anything that drips down the wall goes into the soil/sand.

For the full buiding regs way of doing it you should have drainage channels - a sump and auto pump around the walls.

[SamT]

From what James has described though, a sump/pump wouldn't be needed as the channels could just drain freely out the front of the garage non?

[UnkArl]

The algorithm is always listening, YouTube just presented this video (although I do rate Roger Bisby and the SkillBuilder channel)

[James Malloch]

Thanks for all of the advice! I’ve learned loads from it (and getting into a YouTube hole…).

It was all for a house we were just agreeing a final price for. But another person who offered 2-3 weeks ago just came back and beat our offer (we were about 25k above them) and we weren’t given the chance to counter 🤦🏻

I hope the wall falls down now!

[ali k]

I hope the wall falls down now!

If it’s next to a footpath you could go for a daily walk past the house and slowly undermine it.