Under-house mush

[snedwardq]

I've recemtly rendered the interior walls of my garage in preperation of turning it into a party room. What i have found, though, is that there is damp rising up the inner-most wall. I have had a look under the house and found that there is alot of moisture. i can easily dig into the ground about a foot and find water. The clay is pretty soft.

So, is there any tips on what i can do or do i need to get someone out to take a look?

My backyard is on a slight hill, running down towards the house so I am expecting the water to be from runoff and not any broken pipe.

If i get someone to look at it, what should i be asking them? I don't want to give them a blank cheque and say "go for it".

TIA,
Paul

[Bloss]

This is pretty good DIY territory usually. You need to get the water from behind that wall to flow away from it and to the outside. Sometime it would be enough to simply clear trench all the way along down to below the damp course (if there s one!) or down to just below the top of the foundation/footing. Since anything you have to do next will need that trench anyway then do that first. Then just wait and see for a bit - it might be that exposed to air with no soil directly against the wall it will start to dry out. If it does dry out you can help by applying a bituminous sealer such as Bondall - Water Based Bituminous Membrane (http://www.bondall.com/titerange/waterbased_bitumen.html) to the side of the wall facing the underfloor area you have excavated.

You should also have water drained well off the yard at the top most section of the house facing up hill - that too would need trenching on the outside and rubble and socked ag pipe installed - running the water to the lowest side and into storm water system. Any surface drainage must be held on your land or go into the stormwater system - the pipes your house is connected to or the gutters etc in the road.

You should also make sure that their is plenty of underfloor ventilation in that space behind the wall - no vents blocked etc. Also ensure there are no garden beds adjacent to the house walls - if they are then make suer they are blow the damp curse at least and use plants that need little water so you don't make things worse by watering. If you think there is not enough ventilation you can get double size vents which with a little bit of effort replace the existing single vents.