Plywood as exterior cladding
Jayraja
| Posted in General Questions on
We are in the master planning phase of building a modern house in the PNW. We are in the Marine zone 4c. We would like a clean exterior that fades into the landscape and do not want a house that looks like it doesn’t belong on the land. Considering this, I have a question.
Why isn’t stained plywood used as exterior cladding? Will it work if we have good roof overhangs and a 1″ ventilated rain screen? We are researching this as we would like an organic looking exterior that is clean. It seems like this practice is prevalent in Australia and NZ but not here in the US.
Any thoughts would be much appreciated.
Thanks.
Jay
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Replies
Texture 111 (or T-111) plywood is pretty commonly used for siding. I believe the outer ply is cedar.
Jay,
My guess would be that ordinary plywood would not be considered to look very good, and you'd have to do something with the seams, such as a batten board, which would also not look good every 4 feet. Exterior plywood sheathing has exterior glue, but if it got wet repeatedly, it would delaminate, or at least bubble, over time. With generous overhangs it would probably hold up fine. But, as Stephen mentions, T-111 is a plywood product specifically made for exterior siding. It has grooves intended to make it look like vertical boards and to allow the seams to blend in.That might work for you.
Thanks.
I'll look into T111 plywood to see if it fits our desires.
Much appreciated.
Jay,
Of all the climates to successfully use plywood in, the PNW is probably the most difficult. Here on Vancouver Island I've used plywood for soffits and siding on outbuilding in protected locations. It's possible, but there are drawbacks. It has a tendency to allow mold to get under the surface and for discolouration to occur. Like any wood based-cladding it will eventually need refinishing and this is very difficult with plywood.
If you do decide to go ahead using plywood, rather than T-111, get a grade rated for continuous exposure, not simply exterior grade, and pay close attention to the edges where the ply's are open to absorbing water.
Would cement board meet your objectives?
Malcolm,
Your reply seems to differentiate between T111 and plywood. I was under the impression that T111 is a plywood product. Doesn't T111 have the same moisture exposure problems like plywood?
Cement board does meet some of our objectives. We will probably use some of it on the exterior.
I appreciate the discussion.
Thanks.
Raja,
T-11 is manufactured as an exterior siding and sometimes doubles as sheathing. It is usually also protected by a solid colour stain or finish.There are grades of plywood rated for continuous exterior exposure, like marine grade, but they don't generally have a finished surface you would want on a house. You may be able to find an acceptable mix of the two attributes in some specialty plywood. I'm afraid can't give you much help as to who would make it.
Jay - While T-111 or exterior grade plywood may work, to have it over a rain screen negates its value as sheathing. If you are already going to have sheathing under the rain screen, you will no doubt be one of the few to use T-111 as siding to achieve a certain look, while not taking advantage of its strengthening properties. People use T-111 as sheathing AND siding as a way to save money.I'd listen to Malcolm who knows your climate well.
Thanks for the discussion. Very informative. Much appreciated.