I asked a version of this question once before but didn’t seem to get any answers, so I thought I would try again.
I need to replace my front porch floor. The porch is covered, not enclosed. It sits atop two basement rooms. The porch takes on alot of snow in the winter and some rain when it storms. Gets lots of afternoon sun due to western exposure.
I want to waterproof the rooms below as much as possible. Therefore it seems to me that putting down a subfloor with a water barrier before installing the new porch floor would be in order. However I am concerned that in the process I will trap moisture between the subfloor and porch floor, thereby promoting warping, rotting, etc.
I intend to use 5/4 Cambara of Doug Fir T&G flooring and apply an exterior tung oil product.
Any advice would be deeply appreciated.
Replies
pino.. the gold standard for your situation would be a rubber membrane deck with PT sleepers on it and a draiable deck over....
drainable meaning spaced decking so the rain can go thru and drain off of the membrane.. the sleepers have to provide drainage and the membrane deck has to be pitched to drain...
Mike Smith Rhode Island : Design / Build / Repair / Restore
The problem is the drainable factor.
The current floor is T&G doug fir. A more modern style deck that leaves spaces in the decking just wouldn't look right. To add to my list of challenges, the porch is surrounded by the house on one side (of course) and then two courses of rock face block on the other three sides. Very typical bungalow style. The only space to drain is at the 7' wide steps.
I may try and drill drainage holes in the block and insert a decorative copper tube to allow some water to escape.
Am I creating more problems than its worth by placing a subfloor and membrane under the T&G flooring?
Also, any opinion on vertical doug fir vs. cambara?
Edited 8/26/2003 8:11:10 PM ET by pino
someplace between the elements and the basement rooms you need a waterproof system..
the only problem with teh fir T&G is there will be SOME water get thru.. maybe not much.. but it will sit there and promote rot
prime teh fir decking on all 6 sides before layingMike Smith Rhode Island : Design / Build / Repair / Restore
Thanks! I appreciate your input.
Just a thought for you. I think T&G is usually installed so that the board length runs with the slope. That way, any water that wants to lay in the grooves will drain along them and eventually off the wood. I was thinking of how that would work with sleepers. I'm assuming that the sleepers would be installed perpendicular to the direction of the T&G. This would cause a problem then because any water that made it to the membrane couldn't drain off (each sleeper would act like a dam), right? Is the answer that you need to use two layers of sleepers- the lowermost installed parallel to the slope (to allow drainage off the membrane) and the uppermost installed perpendicular to the lower ones. That way, the T&G could be installed parallel to the slope as well. Not sure if this is really an issue but I think it might be.
Thanks! Your idea is definetely worthy of more thought.
I don't remember If I mentioned it before or not but look at Duradek. http://WWW.duradek.com