I’m doing some work on a three-season (i.e., unheated) porch, approx. 9′ x 12′, located just outside Boston. The current flooring consists of vinyl tile on top of a plywood subfloor which is fastened to what appears to be 5/4″ x 6″ planking spaced approx. 1/8″ apart. Below the planking are the floor joists (pressure treated) which are approximately 3′ off the ground (i.e., open to the elements). The homeowner is thinking about hardwood flooring, but given the fact that the room is unheated, I’m trying to come up with another alternative. The homeowner also nixed vinyl flooring (thinks it looks cheap). I also thought of something like Pergo, but not sure how well that holds up in an unheated space with temperature and humidity extremes. Any suggestions?
Thanks,
Ron
Replies
Ron: Does the room have weather-tight walls? Have you cosidered indoor/outdoor carpet?
Al Mollitor, Sharon MA
Yes Al, the walls are weathertight. Indoor/outdoor carpeting is a good idea, but am not sure the homeowner will go for it. The house itself was built in 1910 and she's trying to stay reasonably true to the materials available at the time the house was made. BTW, the ceiling is beadboard. Her initial thought was actually painted planks (kind of like what's underneath the subfloor), but the idea of being able to see the subfloor in the gaps shot that down... ;-)
FYI, the house is in Medford, MA, not too far from Sharon...
Ron
I don't know that laminate is a good idea. The top surface is durable, but the base material is like particle board. It will swell if it gets damp. Maybe if you put a good vapor barrier underneath. Same issues with hardwood. You may get more seasonal movement than usual, so you may want to install it with higher than normal moisture content or deliberatey gap it. Then it will shrink and you get seasonal gaps, but should not over expand and buckle the floor. Maybe a layer of poly and then rosin paper on top. I've seen porches like that with T&G floors so it it possible. I probably wouldn't want to guarantee something like that.
3/4" t&g vertical sawn fir. 3" width.
Ditch
What about sealing the under side of the hardwood before you put it down. We do that for the cedar t&g that we put on for indoor pools. works great. Don't forget if the ply that is on the floor is exterior grade it should be a good barrier with a coat of paint and proper venting of the crawl space below. I would present the customer with all the potential hazards of hardwood but not embelish. Dry is the most critical so I would predict the appearance of only a few gaps that could be a seasonal high of 1/16 to mabey a small 1/8. This is based on the size of the room. Is this within the tolerance of the customer? I have some that want the floor to appear rustic with larger gaps and beat with a chain.
Scott T.
Tile an option? Scape off the vinyl, screw down CBU, set tile. It would be consistent with the period, no? Don't know about your floor planes, though. FWIW, my 3 season sunroom has tile set just on the 3/4" plywood subfloor (PT joists are 12" oc for a jacuzzi that never got installed) and I have yet to see any cracking of tile or grout. Wouldn't recommend it though, without beefing up the subfloor some.
Just a thought.
Bamboo...
Thanks for all the great suggestions. I'll pass it by the homeowner this weekend and see what she thinks. Will also try to post some photos of the finished job...
Bob: Never would have thought you could get away with tile in that kind of environment. I think the floor is stable enough for CBU, but would have thought the grout would crack from the extreme temperature and humidity changes. I wonder what kind of climate your porch sees?
Ditch: I like the T&G fir idea. Stupid question: would you finish the boards and then fasten them because of the amount of movement the floor will see due to temp and humidity?
Cloud: Bamboo is something else I would never have thought of. Have to look into that.
Ron
I don't know what why there is any question about using "hardwood" floor on a porch.
It is used all the time on exposed porches and decks.
Just depends on the choice of the hardwood.
Ipe and maghony are too common ones.
Bill: On all the outdoor installations I've seen, the boards are gapped (allowing water to run off and maybe for seasonal expansion). The problem I have is that if I gap the boards on the porch to allow for expansion, you can see the subfloor between the gaps. Using T&G may get around that limitation.
Ron