Water coming in New Wooden Garage - Help!!

[Cluffstarr]

Good Morning All,

I bought a new wooden garage (effectively a big shed!) before Christmas and it was fitted in late December.

In order to have it fitted, I did a lot of digging out at the back of my house and had a concrete base poured. The work was done while I was away and unfortunately was not as I had ask for. I wanted a base, a gap of earth and then a retaining wall for my lawn. What I got was a base poured and the wall build on it at the edges. My builder and I had clearly had a misunderstanding but he knocked a few quid off as I wasn't happy. To be fair, the work that has been done is good quality and I have used him again (just with triple clarification of everything asked of him!)

Anyway, this leads to the cause of my issue. The garage was fitted and bolted to the concrete. There is a 1-2 inch gap on each side between the outer wall of the garage and the retaining wall. Rain water can get down there and then seep between the garage and concrete base. The wooden construction is such that there is effectively a 2 inch / 5cm lip / step all the way around inside the garage. This is all hopefully shown on the diagram below:

Garage Layout

• Cluffstarr
• 14 Jan 2014
• 1

I have tried remedying the issue as much as possible with guttering either side and attaching / gluing thick wooden battoning between the retaining wall and garage to cover the gap. Finally I put down a 'join' of Wickes Liquid Damp Proof Membrane (as shown in the diagram) between the concrete and the wood panel base.

I was hopeful that the combination would help to abate the water coming in. It has helped a bit but after rain for most of yesterday, water is still coming in under the DPM and diluting it. I'm sure the DPM is not the ideal solution but I was hopeful it would work for this application. Perhaps in this temperature it will take a lot longer than 16 hours to dry/cure?? It was put down on Saturday and it didn't rain again until Sunday p.m.... Does anyone have any thoughts?

Hopefully someone has some suggestions / ideas how I can cheaply remedy this? I don’t really want to go down the route of pouring a concrete screed inside the garage up to the 5cm lip height (assuming even that would work as the water would hopefully not climb the lip!). The only other thought I had was to lay an edging of concrete mortar around the base to plug it....?

Sorry for the novel above! Hopefully someone out there might have an idea (starting to wish I'd just gone fore a brick built one now!)

Kieran

 

[Burnerman]

Well no one else has commented so here goes......this design will give damp issues to the end of time so if it was mine I'd consider backfilling the gap between garage and retaining wall with concrete.
What do you think?
John

 

[wrathkeg]

Another option: fix something like 100mm DPM or even roofing felt to the side wall of the garage, diverting water over the top of the wall. So a bit like your idea with the wooden battens, but waterproof. Maybe not ideal looks-wise, but might be okay if you do it neatly.

 

[Static]

Photos would help

 

[Cluffstarr]

Thanks to the response guys.
Yes I did think about the felt idea but myself (and my wife!) thought it might not look great at all! I might try and mock it up, pin it down and see how it looks...
I'll try and get a couple of photos over the weekend. I agree that it is not ideal and I am pretty frustrated with it given the quality of the base work and the quality of the garage unit. I don't really want to have to lift the garage out to resolve the issue if I can help it (can imagine it would take several guys to do so...)

 

[wrathkeg]

expanding foam? not sure if it's fully waterproof though, but it is weatherproof. if it isn't waterproof, fill the void at the top with the foam, trim back, then apply sealant at the top.

a bit more thought might suggest this is nuts, but you never know.

 

[Burnerman]

Don't try to move the garage now....there's not enough space around it and the damage could be considerable. Even when using rollers the weight is enormous.
I too had thought about a method of casting rainwater clear, but that would always leave a void which would be damp and a trap for leaves etc.
If my method was deemed suitable, I guess the void could be backfilled with stone, and a thinner layer of compo spread on the top - maybe a bit less drastic than a complete fill.
John

 

[wrathkeg]

my final (?) suggestion. what's on top of the wall? are there coping stones etc.? if not, maybe add some so they are as close as possible to the garage, and fill any remaining gap with frame sealant. might look less like an addition to the wall than a flashing-type solution. and maybe the builder would come back and lay it for you?

 

[r896neo]

A lead flashing is probably the best workable but effective solution.

It could be tucked neatly into cladding if that is the finish of the building.

 

[Cluffstarr]

Hi Guys, thanks for the posts over the weekend. I think I am going to mock up the flashing / felt once the garden dries a little (whenever that may be...) and see if that helps and I am hoping to put down more of the Damp Proof Barrier when the garage is clear of my car and we have a few dry days and it is dry to put down...

Wish me luck - I'll report back!