Thread: Urgent!:Laying floor boards and protection from moisture

Hi Bella,

I'm no expert and just trying to help.
Maybe it would be a good idea to divert the water with some sort of drainage system to stop the water running under the house in the first place.


Regards

Adrian

Have to concur with the above, you're treating the symptom - not the disease.

Its not really that hard a problem to fix, just a lot of digging, no great $$ expense. I would also expect that you will develop many other problems from the damp, smelly rooms, maybe discolouration of walls as damp rises, mould etc etc.

My, probably unwelcome, advice is dig the drainage and airate the sub floor space - sorry.

I have to agree with julissee on this as water run off under your house cannot be good for it. The first job we under took when we bought our home was to install a stormwater run off plan to keep it from under the house. The area around the stumps have suffered from rain water errosion and I will have to throw some clean fill in around them.

To add to the already good advice, dampness under your house is a real attractor of termites as well. Neither priming the underside of the boards nor sizlation will stop those little buggers. :mad:

We have already installed slotted PVC right around the house to stop most of the water but when there is a big down pour a bit of water still seeps through somewhere.

Get aTRADESMAN to fix your house properly and you won't have any hassles

Bella,

Have had this problem, low clearence under floor, poor ventilation, moisture problem when it rained a lot. End result, after several years mind, was wood rot. Had to rip the lot out, only about 4 by 3 metres though.

My solution: re-leveled the back yard, new concrete foundations and brick walls, with lots of dampcourse, dug out the offending area under the floor, put in several ventilation points so the air could flow through under the floor area, extended roof line for more weather protection and,... got new recycled Jarrah floor boards. Laid the little fellas my self.

I am told that ventilation and about 450mm from floor to ground is what is recommended for good protection for wooden floors. So I am with the others here, fix the cause of the damp, would hate to see you have to do what I had to. I think that there is some black stuff you can paint on brickwork to waterproof it and perhaps a layer of coarse gravel against the wall to help the water drain away could help. Best consult an expert as Christopha suggests I think.

Anyway, best of luck.

Cheers
Pops

Originally Posted by Christopha

Get aTRADESMAN to fix your house properly and you won't have any hassles

My husband is a carpenter!! And we hired a plumer and a landscape gardener to look a the drainage. I think I can safely say that even tradesmen can't get it right.

Plus the house is 80 years old and the floorboards are still as solid as a rock so I don't think that we should have any issues, but we always like to take precautious to be on the safe side.

I am surprised at how narky some of these responses have been and only a few people actually had something constructive to say. Thanks Pops.

Everyone was trying to be helpful not narky.

Christopha was in telling me to fix my house properly with a TRADESMAN (in bold capital letters), inferring that we hadn't done the correct things.

G'day.

Firstly, have an Aggie drain placed around the high side of the sub-floor area.

Is the subfloor enclosed... ie: bricked in?

It is possible to cover the sub-soil with black builders plastic with all the joints tapped with good quality 200MPH tape. also tape up around the piers. This will seal off the sub-soil from the underside of the floor.

painting the bottom of the boards with a extra heavy coat of oil based paint will minimise the amount of moisture uptake by the flooring.

Also, can the new floor be laid over the old floor?
The old floor would act like a moisture barrier.

Has the moisture content of the old floor been tested ?

If so, what was the corrected moisture content?

I hope this is of help to you.
Please let me know via PM if you have any questions.

Hooroo.
Regards, Trevor
Grafton

Hi Trevor,

The whole area is surounded by slotted pvc and screenings which seems to have stopped the water running under the floor by about 96%. So I am happy about that. The floor is on concrete stumps and has pretty good air flow and the bearers are about 300mm off the ground.

The black plastic is a good idea. We had to rebuild the floor with new (higher)bearers and joists up to the same level as the rest of the house so couldn't build over existing floor.

We haven't tested the moisture content but 90% of the time it is dry under there.

Might have to give the black plastic a go I think.
Thanks Trevor.

I too was a bit taken back by the tradesman comment, and agree that it wasnt called for.
Bella do you only get water under the house when you have heavy rain or all the time?
If it happens all the time and the existing drains dont work on the perimeter maybe placing drains under the house leading outside maybe an option.
Another option Ive been looking at lately especially in my house is putting blanket insulation under the floor, you can lose up to 20% of your heating with un insulated floors, Ive been looking at this product, http://www1.aircell.com.au/ . It may be an option.

where in Melbourne are you? Is your block on a slope or flat?

Hi Dan,

It is only the heavy rain storms that we get some water dribbling under the house and only in one corner. The drains catch the rest and take out to the street.

We are in Foostcray and the block is flat.
I'll have a look at the aircell idea. Sounds like a good idea.

Cheers,
Bella