i built a porch over the summer, here in toronto. for one reason or another, the floor ( 1×6 t & g doug. fir laid directly on joists ) didn’t get varnished until early october. it was a very wet summer and fall, well spring also, here. now i have a pretty serious issue. the floor has buckled very substantially in one spot, and i need a solution. i covered it with plastic, hoping to keep rain and snow out, and drive the moisture down through the bottom of the floor. it’s just gotten worse. i suspect what happened is that the floor wasn’t dry when it was finished. any thoughts?
Replies
It looks (close as I can see through that plastic) like the flooring was installed a hair too tight (and too dry!), and when it absorbed some moisture it expanded in width. May be exacerbated by humidity rising up from below. (I assume it's dirt crawl below.)
First, spread plastic on the dirt below, to reduce the moisture rising up out of the ground. Then try weighting down the buckled spots to see if they will go back flat. If not you'll need to remove some boards and trim them for width a hair.
What is obvious is that the wood has swelled from moisture. Dan might have a good point about moisture from below. Is the space under this vetilated? It should be.
If not, the ground moistrue is rising, and then you trapped it in the boards when you finally sealed them.
The right way to do this job is to build with venting under the deck, and to seall all six sides of each board with at least one coat before installing them.
What to do now depends on whetehr you can dry things out or not. That plastic is just trapping the water and not helping a thing. Step back and shoot a couple photos of thed whole sheebang
It's probably a good thing you didn't varnish, you might have the finish coming up too!
Yes, as the others have mentioned the moisture expansion had caused this. Pull the plastic now so it can dry again. You shouls also pull the boards up and stack them with spacers to the side to let them acclimate to the ambient moisture level outside. Put some plywood down whil you work out the moisture issues under the porch.