We are having a new garage/workshop/cave built. Fairly simple, but solid, so we went with single skin brick and block, with piers and tied across the top. It looks great, but we’ve noticed that with the heavy rain, Water is pissing through below the dpc. The bricks are laid on a wider concrete raft, rather than pouring the slab in a substructure and lapping in.a dpc. below the dpc are engineering class b bricks but now we’ve looked,Some of the mortar is v sandy. We suspect the “lad” they had mixing mortar hadn’t been given proper instruction and the bricky was either didn’t notice or didn’t care. Its probably 5:1 rather than 3:1 as I believe it should be below the dpc.

So the building is up, roof is on, basically finished. Wondering about a solution, potentially a diy one as the builders do seem to make a meal out of everything. My initial thought is raked bit of the mortar out of the bottom course and repoint with sikadur 33, an epoxy concrete repair mortar. It should be totally water proof, and stronger than a dodgy pointing jobi could manage with traditional cement and sand as its like applying bathroom sealent out of a gun.

Then perhaps, once it’s repaired, tanking it with a waterproof slurry compound, just the bottom course,  where the water sits in bad weather

Any thoughts?

Get the shoddy b******* to rebuild it, or was it a cash job?

Is the water not just tracking across the dpc?

Is it rendered ? Blocks brick and mortar are not inherently waterproof you know this ?

mortar is v sandy.

In other news, chips are v potatoey and kippers are v fishy.

If it’s leaking to that extent then I’d be looking for a gap

Am I right in thinking it’s built off a raft? This raft then projects past the external leaf of the garage. Is the raft also the same level as the internal floor?

That’s correct wrightyson. There are aco drains up against the wall on three sides, but on this damp side, the wall has been built maybe 2 inches off the aco, leaving a little lip (with no fall on it either way)

I reckon the moisture will be tracking across or under the dpc then, its a common problem. Even with waterproof pointing it may still occur. Any chance of running a saw down the overhang, chopping off then relaying the aco?  If not, a possible solution is wait till it’s bone dry (good luck with that) rake out a good 10/20 mm depth of the mortar joint, cut back the dpc, remove all traces of dust and liberally fill and tool that joint with clear silicone. Then form a smal 45 degreel mortar fillet over that joint with perhaps a sika or sovereign additive, not ideal but maybe an option. Whatever happens you must cut back the dpc so that it recieves a good covering of whatever method you use as id say that is what’s causing the issue.

Wall to floor joints are always a big weak point where water ingress is concerned

Silicone brick seal.

Though i think it’ll be tracking over the dpc.

Single skin of brick, if the bricks get saturated from constant wind and rain you will get the pleasure of watching the water running down the inside of your garage, summer and spring will be fine but wet this weekend

I had a similar problem, which was my own fault but luckily it was sorted by using this stuff https://www.wickes.co.uk/Ka-Tanking-Slurry—Grey-12-5kg/p/139057 May be cheaper elsewhere, I just selected the first link.

I tried to lay 2 courses of bricks myself (I’m not a bricky) and sit a shed on top. The brickwork leaked terribly when it rained so thought I would give the tanking slurry a shot and it worked. 2 years down the line and we are still leak free. Downsides are its a one shot deal as far as I’m aware. If it doesn’t stop the leaking, I don’t think you can paint more on top.