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johnm126
Buckling porch floor

I replaced my porch floor in summer of 2010,with tongue and grooved.There is a basement directly underneath porch and there is a subfloor underneath the tongue and grooved boards.I dont remember how long after replacing them that I painted floor .I did use oil base porch floor paint.Today is first time I really went out of porch since winter about week and half ago we were still in to 20s for temp it has now warmed up to 50 and 60s.When I went out there were several that were buckling up .It was nailed properly. So whats causing problem and will I have to rip it all back out to correct it. thanks for an info on this.

HoustonRemodeler
Re: Buckling porch floor

John,

Did you lay these boards all nice and snug together thinking they were supposed to be that way? If so, you may have nailed them too close to each other. They need room to expand and contract with the changes in humidity. Painting / sealing the boards exaggerates this effect as the paint will act as a lid keeping the moisture in the boards longer. Aside from a re-do, I am not sure what can be done now. Perhaps another Pro will have some ideas.

Sombreuil_mongrel
Re: Buckling porch floor

Is this an exterior porch or one that has been enclosed? You never lay exterior porch flooring over a subfloor, unless it's on sleepers and ventilated. You would be creating a wood on wood sandwich which is a water trap. No wonder it buckled.
A porch deck over heated space has to be treated as a roof. The waterproofing and walking deck functions have to be divided; you first build a waterproof flat roof, then install a floating walking deck on top of it, without penetrating the roofing.
If it was an enclosed porch, you probably just needed to backprime the t&g material, then set the boards with a small space between each for expansion; a dime thickness is about right for 1x4's.
Casey

Timothy Miller
Re: Buckling porch floor

Howdy did you leave clearance around the perimeter to allow for expansion of the T&G flooring? If not buckeling is common. Got a leak in the roof or wall again causing the floor to swell?

Timothy Miller
Re: Buckling porch floor

lastly check the humidity level in basement if real high the moisture transfering threw the floor can buckle it too.

johnm126
Re: Buckling porch floor
Sombreuil2oo wrote:

Is this an exterior porch or one that has been enclosed? You never lay exterior porch flooring over a subfloor, unless it's on sleepers and ventilated. You would be creating a wood on wood sandwich which is a water trap. No wonder it buckled.
A porch deck over heated space has to be treated as a roof. The waterproofing and walking deck functions have to be divided; you first build a waterproof flat roof, then install a floating walking deck on top of it, without penetrating the roofing.
If it was an enclosed porch, you probably just needed to backprime the t&g material, then set the boards with a small space between each for expansion; a dime thickness is about right for 1x4's.
Casey

this is a older home probably close to 100 years old, this is way it was built the subfloor then the porch decking.it does have a roof over porch but not enclosed.Ive owned home for app. 11 years now and its never buckled till I replaced it.I cant do any building up to get air flow between subfloor and porch floor because of doors going into house.any other suggestion. thanks

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