Rain soaking through garage

HatMan92

Hi all,

I live in a recently built new build, and particularly recently I’ve noticed that one wall of the garage is particularly wet whenever it rains.

For reference, it’s a single skin garage. I’ve attempted painting the exposed brickwork with Thompsons Water Seal, but potentially it was on a day when the brickwork was still too damp, so I will give this another go at some point in the future.

I’d love to know if you have any recommendations for what I should do?

One local chap suggested I need to carve back that last row of paving slabs by about 6-7 inches, and then backfill with gravel or pebbles as it’s likely the water is sitting on the pavers and then getting sucked up by either the brickwork or the mortar. Others have suggested I need to put in channel drains around the garage perimeter. Obviously cutting the slabs back and backfilling is something I could do with the slabs in-situ, but adding a channel drain and attaching it to the existing drainage is a bigger job that I’d likely need a professional for?

We’re outside the initial builder warranty period so getting them in to sort it is not going to happen.

Any help is greatly appreciated … thanks in advance!

[Deleted User]

Hi,

maybe just the second photie, but looks as though any rainwater runs towards the door, maybe wee sandbag type thing would help.

HatMan92

frugalmacdugal said:

Hi,

maybe just the second photie, but looks as though any rainwater runs towards the door, maybe wee sandbag type thing would help.

Hi, I can also take a level to it later once it’s stopped raining, but it seems fairly flat to me so this might be part of the problem too. The second photo, the pebbles on the left are concealing a French drain because at one point all the water was just pooling on the pavers. The builders rectified this as part of snagging, but I’ll admit I never checked that the fall was away from the garage or anything.

Section62

HatMan92 said:

I’d love to know if you have any recommendations for what I should do?

On the second photo there is what looks like a gutter downpipe (RWP).  Where does that go to - i.e. is it to a drain or a soakaway?  Is the underground pipe damaged or missing?  Just because the pipe looks Ok at ground level doesn't mean it can't be horribly defective below the surface.

It appears the level of the garage floor is slightly lower than the ground level outside.  Which means unless the builders took extra care over damp proofing, damp patches on the garage floor were an inevitability.  There's little point using paint on 'cures' - if there is a path for water to get from the outside to the inside then the only really effective cure is to provide a route for the water to follow which is easier than the one that goes to the inside of the garage.  I.e. if the RWP is going into a fully functioning drain of some kind then use that, extended, to drain water away from the sub-soil adjacent to the garage as well.  Bear in mind in some areas there are rules regarding "land drainage" not going into surface water drainage, so do some research to make sure you stay on the right side of any applicable regulations.

subjecttocontract

It looks to me as though the outside ground level is to high. It should be 2 bricks below the damp proof course. If it were me id remove some of the soil around the outside corner and any other areas that are above that line.

HatMan92

Section62 said:

HatMan92 said:

I’d love to know if you have any recommendations for what I should do?

On the second photo there is what looks like a gutter downpipe (RWP).  Where does that go to - i.e. is it to a drain or a soakaway?  Is the underground pipe damaged or missing?  Just because the pipe looks Ok at ground level doesn't mean it can't be horribly defective below the surface.

It appears the level of the garage floor is slightly lower than the ground level outside.  Which means unless the builders took extra care over damp proofing, damp patches on the garage floor were an inevitability.  There's little point using paint on 'cures' - if there is a path for water to get from the outside to the inside then the only really effective cure is to provide a route for the water to follow which is easier than the one that goes to the inside of the garage.  I.e. if the RWP is going into a fully functioning drain of some kind then use that, extended, to drain water away from the sub-soil adjacent to the garage as well.  Bear in mind in some areas there are rules regarding "land drainage" not going into surface water drainage, so do some research to make sure you stay on the right side of any applicable regulations.

Hi so I believe that is actually connected to a drain, I’ve got the engineering drawings for the house and basically closer to the house (I.e. behind picture 2) is another drain that’s been cut into the pavers. Those drains meet up underground and then run across my garden and out into a water drain that a few of the properties are all plumbed into. 

What I am understanding from your comment is that if I cut back the pavers and lay aggregate in the gap, and I continue to have issues on the same scale, then the installation of further proper drainage is really the only way to go in terms of long term rectification?

I’m not necessarily looking for the garage to be watertight; it’s just been particularly bad this year and so anything I can do to mitigate it is worth considering. Long term we want the garden landscaped in the spring, so I’m going to have to expand the plan to include proper drainage around the garage now.

diystarter7

Hi
Is the outside sill very slightly sloping into the garage? And or levelish but allowing water to gather and then pour through a gap?


Thanks

EssexExile

I'm with "subjecttocontract" above, the ground outside is above the garage floor. That can't be right, surely the builder should sort it out. Otherwise just lower everything close to the garage to below floor level.

MikeJXE

Why are you asking this, if it is a new build then it's the builder to sort out. 

Section62

MikeJXE said:

Why are you asking this, if it is a new build then it's the builder to sort out. 

See the first post -

HatMan92 said:

We’re outside the initial builder warranty period so getting them in to sort it is not going to happen.

HatMan92

EssexExile said:

I'm with "subjecttocontract" above, the ground outside is above the garage floor. That can't be right, surely the builder should sort it out. Otherwise just lower everything close to the garage to below floor level.

MikeJXE said:

Why are you asking this, if it is a new build then it's the builder to sort out. 

Ordinarily yes, we've still been working through the snagging list which had some more notable & significant issues and this has only been this bad this winter; we fell out of the warranty period towards the end of last year. So basically we've missed our shot, and would have to take it up with NHBC.

NHBC will investigate it, but as it's a garage, their own technical standards hold that it's unreasonable to expect a single skin garage to be waterproof / immune from damp as it's not designed in accordance with their technical standards. Also the NHBC policy will only pay out of the cost of works exceed the threshold value which is close to £2000, so either way I'm going to have to pay a tradesman or do the work myself.

I'm fuming, but mostly I just want a dry garage.

diystarter7 said:

Hi
Is the outside sill very slightly sloping into the garage? And or levelish but allowing water to gather and then pour through a gap?


Thanks

Having just been out there, there doesn't seem to be much of a slope on the patio at all.