Rainscreen – 1×4 strapping or 3/4″ plywood
Hi,
It is worth the extra working of cutting up 3/4″ plywood in 3-1/2″ strips or simply buy the 1×4 strapping?
Pricing
1x4x8′ strapping: $4.58/ea
3/4″ plywood give 13 strip @ $5.61/ea
Thanks,
Arnold
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Replies
Arnold, the performance will be pretty equivalent, though plywood will be less prone to splitting and 1x4s might hold up better over the decades. That aside, including setup and cleanup, it might take about one minute per strip. If your time is worth $60/hr, that's $1 per strip, which makes the cost difference closer to $2 per strip.
Hi Michael,
Since I'm building my own house, time isn't the most important factor. I was originally leaning towards 3/4" plywood but I'm not sure it's wroth the cost and extra time if there isn't enough benefits.
Arnold
There's nothing wrong with either, though it's fairly quick to load up a bed up 1x4's ready to go, and get along with other tasks.
1x4 are pretty solid, unless you are driving in some larger fasteners, you shouldn't have any problems.
I would use ripped CDX for corners and around windows. Make sure to rip them wider around corners so they can reach past to the corner studs.
P.S. Lot of 1x4 nowadays is closer 5/8, so check what you get and match the CDX to it.
3/4"-1" seems a pretty generous gap. 3/8" or even 1/4" ply strips could work?
I believe 3/4" is pretty standard gap due to it being the thickness of 1x3 and 1x4 strapping that's commonly used. but other gap thickness can also be used.
Arnold
woogagoobaa,
There are a few disadvantages to going too thin. The main one is that if you are using building paper, or a synthetic WRB like Tyvek, they don't lie entirely flat and can bridge the gap between the sheathing and cladding. That both defeats the function of the cavity as a capillary break and impedes air flow.
We specify 1/4" when the furring strips are going directly over the sheathing, and the siding is fastened through the strips into the sheathing. 1/4" is plenty for the rain screen itself, although Malcom's point about uneven WRBs bridging the gap seems like a fair caution.
We specify 3/4" furring when the furring strips are going over continuous insulation, and the siding is fastened to the strips themselves (per R703.15.2).
I went the plywood route largely because 1x4 stock in my area is horrid - 9 out of 10 will be warped or twisted in some way. Cutting the strips from plywood at least gives me a flat and straight basis to work from, even though it is more work.
I would absolutely have gone with 1x4's if they were more reasonable, though, if for no other reason then that's that many fewer sheets of very heavy plywood that I would have to haul around.
Hi Kurt,
I have to pickup a few things to complete the electrical service installation so I'll check out their inventory of 1x4 strapping and see what they look like. Maybe that will help make up my mind as to what option to go with.
Thanks,
Arnold