Hello All! I’m in the process of building the porch on a new home I’m constructing for myself. The floor will be tongue and groove fir and will obviously have no drainage without a pitch. Is there a standard pitch that is used for this application? If so, what is the magic number?
Thanks in advance.
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Replies
Tony,
The rule that I've always heard is that 1/8" per foot is the minimum slope. That's what I used on our new porch (built about 10 years ago). I also used t&g fir for the floor. However, I've had some rot on boards close to the edge of the porch which needed to be replaced last year. I think it's the snow melting and then re-freezing at the edge. The problem may not be the slope. I put the last piece of flooring at the edge perpendicular to the rest of the flooring and this piece wraps the porch floor. It may also be traping moisture. Also, I did not prime the underside of the floor. Avoiding these mistakes may help prolong the life of the floor. Still, I'm not sure that fir is the best choice for a porch floor. If I were to do it again I would opt for a more decay resistant species.
Chiptam, Thanks for the reply. I also was going to butt the ends into a perpendicular strip of flooring which would frame the floor. I've also seen the effects of not back priming a fir floor and it wasn't pretty. The house that I presently live in had a fir porch floor which was recently replaced after about 80 years of service so I think the material is fairly suited to this application if care is taken to keep the material dry and sealed.
1/8" per foot sounds reasonable. Thanks again
I've heard 1/8" to 1/4" per foot. You might want to take some plywood and shims, and set up a temporary example of those slopes to see what feels OK to you.
-- J.S.
Tony,
I put a 1/4" per ft. pitch on porch floors, and definetly back prime!
Good luck!
Jay
J. D. Reynolds
Home Improvements
"DO IT RIGHT, DO IT ONCE"
Jaybird is right, 1/4" and prime all raw wood including the ends. You may need a vapor barrier if the porch is sealed in or air tight.
charlie
With a roof over 1/8" is OK but for open decking, minimum of 1/4".
I recently began using gorilla glue in the t&g joints for protection against moisture penetration also.Excellence is its own reward!
Piffin, The Gorilla glue for moisture protection sounds interesting. Is there a concern however, with eliminating the natural movement of the flooring at the joints by gluing? Just a thought...
Tony,
Could be. doesn't seem to be a problem so far after two winters on the Maine Coast.
I get architects who specify fir T&G on porch decks and expect it to act like a roof to keep things dry down below. I laugh at their assurances that it won't leak, tell the owners to expect leaks and then do my best to seal'r up snug.
In my opinion, the old proch decks with fir T&G were under a roof and were painted severely to protect them. Now we've got people expecting poorer quality fir to perform just as well right out in the wind, sun and rain as it did back then under shelter. An open deck should have square edge boards to let the water drain and the air ventilate. They should all be sealed at least every other year.
But if they don't want to follow my advice, I make good moneyu doing it over again. C'est la vive!
I just spent a week replacing a five year old wood gutter because the caretaker was too lazy to clean it or oil it every year. the downspouts werer plugged plumb full of debis so the water sat and evaporated out of the gutters. That is, except for where it soaked in and caused rot.
Now you've gone and given me an idea for another thread. Look for "Owner maintanence required" coming soon to a breaktime near you.
Excellence is its own reward!