I’ve got a problem with a second floor covered (but not screened) porch and don’t know of the correct solution. First the facts:
- Its constructed of 1″ x 4″ tongue and groove pine (not pressure treated).
- It is mounted directly to 2 x 10 pine joists with 12″ centers. (no subfloor or underlayment)
- It has had two coats of Olympic Deck paint (supposedly with water protector in it)
- The paint seems to be protecting the surface of the boards ok Its been in place for 5 years
- Its a northern exposure and is protected from driving rain most of the time (our weather in Western PA comes primarily from the southwest).
Today I had a chance to replace the first piece of tongue and groove since water has seeped through the cracks and rotted not only the flooring but is starting to effect the joists. The rot is working in thru the sides of the tongue and groove where there was no paint and is rising from underneath.. Since the porch is about 10′ x 40′, I’m not wanting the whole thing to disintegrate and I’m wondering what type of paint or other surface covering has the best chance of sealing all the cracks and keeping the water out. I’ve thought about Rustoleum’s Epoxy covering (too brittle?) and some type of polymer based coating with some flex but don’t know of a brand.
If I had built the house myself, I’d have chosen one of the new composite materials but its too late for that so I’m hoping someone can lend a hand (or a thought). Thanks
Edited 8/30/2004 8:31 pm ET by Rather
Replies
What you are up against is less than top of the line design and installation.
An exterior deck is best done with square edged stock instead of T&G brecause it will trap the water in the grooves and rot faster there.
But T&G is often used when protected by a roof over and it can be done successfully. The thing that has to be done is to use clear verticle grain fir and to seall all six sides befor installing it. your builder used pine instead and probably did not seal these edges. If the framing is not pressure treated lumber we would use narrow 2" strips of 30# felt over it and under the decking to keep the water and rot out of it.
All of that in retrospect is not to berate you for the past, but to help others who are considering such a deck.
Since you already have the situation, you could inject Minwax wood hardener into soft spots or use Abatron repair epoxy to take care of what is starting to weaken, and then do your best to keep a good coat of paint on the surface to repell water. The problem going forward is that it will try to break seal at the joints in the decking boards. Eventually, you will probably need to replace the deck. Sweep the snow ice and water off to keep it longer.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Thanks for the very quick response. I wish the original contractor had the benefit of your advice. What do you think of an epoxy paint? Think it will prevent seepage through the cracks?
I can't say. My only experience with epoxy paint is on concrete and steel. if it cracks on seams of the decking, it would only be marginally better than any other deck paint because the water would still get in at the weakest point. The plus side is that it will dfinitely weart beeter under foot traffic and be more impervious to water intrusion otherwise. Probably worth taking a chance on it though.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I hope you meant 2x10 joists, Nothing will keep the water out of the cracks.The porch should be pitched to shed water and the water should flow unimpeaded off the deck. I agree that the sides and bottom should've been primed. The top is primed with the deck paint.(its usually self priming). You dont want to see primer when the top layer wears through.Is there a finished ceiling below?
Mike--thanx for the response. Yes, there is a finished ceiling below...beaded and stained tongue and groove. l really want to protect that as well as the tongue and groove flooring on the top of the joists. (And yes, it is 2 x 10 joists. The problem with any pitch to the porch is that the numerous joints run perpendicular to any pitch so the water tends to "catch" in any slight cracks between the boards.
The finished ceiling makes the water problem worse, it has nowhere to go.You will never keep the water from migrating with paint or caulks.you can protect it You can protect it with an awning,or building out the eaves,or rebuild with another design or enclose the porch.Is there a wall that prevents the water from falling off the porch?
I think the idea of using wood hardner on the punky wood and filling lost wood with epoxy filler is a good one. I was thinking maybe using some paint that is rubbery and flexible--like is used on garage floors, basement walls, swimming pools. Don't know if there is such a paint for wood though. Depending on ceiling height, you could sort of start over and put something like EPDM down, then sleepers, then a new deck. Still wouldn't help that much if the original floor isn't pitched for drainage.
This would probably be expensive and a pain to build, but you could shim plywood over the floor to get some pitch for drainage and then paint the plywood with some rubbery, waterproof paint.
OMG, "The problem with any pitch to the porch is that the numerous joints run perpendicular to any pitch"
This builer's head was up his hidyhole or his kids were playing with his brain and left it out in the rain where it rusted
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Now that you have revealed the fact that there is a ceiling underneath this decking, I think I would seriously consider sacraficing the pine decking to save the ceiling and the framing. As Piffin noted...it's a poor design, and probably destined to fail you sooner than later.
I agree with dieselpig, sacrifice the pine. Replace it with a better material and install it appropriately.
Also, while the deck is off, repair the joists as necessary. Consider whether vents between the deck and ceiling would be appropriate. And, were it me, I would treat all the temporarily uncovered wood with borates and/or ethylene glycol.
Rather,
The traditional way this was done was to put canvas over the decking. I've never done it but Old House Journal had some articles. A newer approach to fix this would be to use something like Gacodeck.
http://www.gacodeckkit.com/
KK
I second the vote for gacodeck. I used it on a porch with old t & g over a basement office in Portland, OR. I had minimal tolerances due to a front door and this product was just the ticket. So far, 4 years, it's held up and is still keeping the office dry while not showing discernible signs of wear. It's also easy enough to install properly and doesn't take anything special to put down. I'd use it again if the situation called for it.
The only viable option for a reasonably permanent fix would appear to be some sort of membrane, either something like EPDM or a "paint on" membrane like Gacodeck.