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Damp Garage Floor Advice Needed - How to Resolve Constant Damp Issue?

Postby epichouse » Mon Sep 08, 2014 7:30 pm

I'm briefly looking into how to cheaply sort out an old garage floor (for my father).

It's almost constantly damp, due to some kind of water course that seeps through the land between the houses. It has always been like this.

The garage is an old one, built on top of a tarmac driveway that runs between two semi-detached houses. The houses next door are higher up by a good five foot.

The floor is therefore tarmac, the sides are cast concrete (pebble dashed outside) and the roofing is asbestos panels - which have since been covered over with steel corrugated panelling to keep the rain out.

Seeing as there's constant moisture seeping under the tarmac and perhaps even over the tarmac at times, it tends to soak up into the garage, making the whole thing damp.

Anything stored in there just rusts and/or goes mouldy. (The thing is full of old junk in various states of rust and disrepair). It is a bit of a poor selling point for the house.

It is too big a job to pull the whole thing down, especially dealing with the asbestos, which we suspect will be a nightmare and costly to dispose of.

We therefore want to try and leave it all in place and just make the garage less damp - as easy and as cheaply as possible, preferably DIY.

I've found some kind of plastic floor covering that pours out like paint and then sets. However, I do not know if doing this would just cause more problems, giving the water nowhere to go.

I have also found some hollow decking (polyethylene and timber composite) at b&q. ( ... m-13748693).

The idea of getting some old wooden forklift pallets was also being considered to do the same kind of job of creating a "spaced-off floor", but they may be too thick and too uneven. The composite material doesn't rot and is waterproof. It is quite expensive, but it may be the easiest and quickest to lay.

The concrete walls are actually not too bad when you are above a few inches off the floor, it is mainly the floor that's the problem. There's not enough room between the houses to park a car in the garage, so weight is not a problem. At most, it needs to take a motorbike.

These are just basic ideas at the moment. Can somebody advise what may be the best way to sort such a problem out?

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Simply Build It

Postby welsh brickie » Tue Sep 09, 2014 3:57 pm

The best way is to raise the floor by concreting it, this will prevent it from flooding, then at a later date you could tile it to stop damp from seeping through.
There isn't a cheap way to avoid it really, if you want to stop it from flooding
welsh brickie
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Postby epichouse » Tue Sep 09, 2014 7:48 pm

Thanks for the quick response, Welsh Brickie.

I don't know much about concreting and how thick it may need to be etc, but I think my father might.

In my own mind, I suspected it might just leach through the concrete - but in hindsight, it is of course going to be very different to the current porous tarmac.

Seeing as the concrete could be neatly set to the shape of the wavey walls, this may be much better than having to try and fit flooring and/or having gaps all around the edges.

In addition, we could later have some luck with treating the concrete with some of that sealing paint stuff you get in tins.

I will pass on the advice to my father. We might be looking at emptying out all the stuff doing it before it gets too near winter.

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