Rainscreen Low cost durable options
sean1918
| Posted in General Questions on
Building in Maine Zone 6, using a WRB (siga swiss majvest 200) over plywood. Thinking of using either LP or hardi batten board siding. Curious, what are affordable long lasting rain screen options? Designer picked out a more expensive I believe Watairvent, however I am curious of what people are using.
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Will your siding be horizontal? If so, since 1x3 strapping is available and pretty affordable in Maine, I generally use that. If your siding will be vertical, the best rainscreen is cross-strapped 1x3s.
We were 75% of the house with Batten Board...planning on LP products, however these is a very slight chance could deviate to Hardi. The other 25% would be traditional clap board. So it sounds like with batten board the 1x3 is rainscreen should be horizontal and with clapboard the rain screen would be vertical? Is this correct? And I prefer cheaper anyway so dimensional sounds great.
Sean,
Rain-screen furring should never see enough moisture to damage either strips of CDX plywood or 1"x lumber. To me, proprietary materials are best reserved for situations like vertical cladding where those aren't an option.
Watairvent looks like a good product. It's a shame the manufacturer included such puzzling claims as:
"Meets the National Building Code of Canada capillary break requirements for high moisture index" The NBC is a model code, so that's meaningless.
"Available in black for UV resistance" In what circumstances would that be useful?
"Manufactured with fastening slots to allow for differential movement during installation." Any movement will occur seasonally, not during installation.
We are using 75% of the house with Batten Board...planning on LP products, however these is a very slight chance could deviate to Hardi. The other 25% would be traditional clap board. So it sounds like with batten board the 1x3 is rainscreen should be horizontal and with clapboard the rain screen would be vertical? Is this correct? Sounds like dimensional lumber is the best to use. thanks
Sean1918,
I am in the area and also vote for pine strapping. I have had good luck with going to the actual sawmills and buying large packs of stained pine for far less money. I just bought 2500lf of 1x4 for 6 cents a lf. That's low cost and local!
wow....are you in maine? Where did you buy it...thats great
Sean1918,
I'm in conway nh on the border. However, I got it at Limington Lumber in Maine. Most of the sawmills will sell you large packs for lower cost. It's not by the piece. Good luck.
I like to use 3/4" cdx plywood ripped down. Can get 20 out of a 4x8 $40 sheet. Which is about what 1x3 furring strips cost here. Straighter, don't split, no beavered edges. The small amount of extra labor to rip them is well worth it.
Just so you know Joe Lstiburek's option and experience with battens--regular untreated lumber/strapping is fine in a typical rainscreen application. This assumes horizontal siding and vertical battens/1x3s. If you are putting battens horizontally, you have then blocked drainage and airflow.
PA-1201: Foam Shrinks, and Other Lessons
https://buildingscience.com/documents/published-articles/pa-foam-shrinks/view
Furring strips will not rot
I can’t tell you how many times I have heard, “You’ve got to use pressure treated furring strips,” but it is absolutely untrue. When we took the walls apart, the furring strips looked brand new. Why does this detail work? Because the vent space is designed to dry. That is its whole job.
Why not use pressure-treated furring strips as an added measure of protection? One reason is that it means having to use stainless-steel siding nails, which has proven to be an unjustified extra expense.
Kohta,
We are lucky here in that Micro Processed Sienna (MCA) is supplanting ACQ treated lumber, so the problems of corrosion we saw in the past don't occur.
Thanks for replies everyone. I was wondering about the cross strapped/horozontal 1x3 lumber rainsceen...I would think that would block the drainage? Or does it not matter as vented and little water goes there so dries out?
This question made me remember a project we had to repair a few years back. The previous contractor had used hardi strips for the battens. They were installed with AQI treated screws. The issue was that the cement in the hardi battens stripped the coating and left the raw ferrous part of the screw exposed. It had oxidized and the battens and siding were starting to fall off the house. I wouldn't have ever seen that coming, but... makes sense.
In a more direct answer to the Q: just use dimensional 1x3's. Cheap, easy, effective. For the cross strapping, go vertical up against the WRB and then horizontal. The little bit of water that may land on the horizontal 'shelf' is minor and will dry out.