B&B siding, furring, and the drainage plane
Gene_Davis
| Posted in Construction Techniques on
How is this best done? We don’t want to mess up the insulation cavities of the studwall by doing between-stud blocking, thus we need outside-the-sheathing horizontal furring. How ya gonna get a drainage plane thing going with those furring strips providing dams at regular intervals? Kerfing the furring strips sounds like a nutty and expensive thing to do. Is there a solution?
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I would buy PT or WRC 1x4, rip it down the middle with a 30 degree bevel so's you end up with two identical pieces, and nail those over the felt across the wall with the bevel up and sloping away from the wall. I would install them 24" O.C. If there is water flowing down the back of the siding (which is pre-primed or oiled) it will accumulate on the furring and eventually drip down the gaps between the boards, behind the battens. There are plastic battens like El Dorado and others that might work well also. I have done a lot of B&B and IMO solid 2x blocking in the wall is best for siding attachment, but the value of a rainscreen probably trumps that. I don't know that 1x furring will hold nails like 2x will, so I'd be prepared to use screws in the battens if need be. The nails in the boards themselves are inconsequential.
Either cut weep grooves (vertical) on the back side of your horizontal nailers, or use one of those plastic sheet "waffle" screeds cut into strips underneath your horizontal nailers.
Check out this article
http://www.coastalcontractor.net/article/135.html
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I'm specifying smartframed
I'm specifying smartframed walls, meaning 2x6 studs on 24 centers, yadda yadda yadda, all to maximize thermal performance.
We'll definitely want furring run horizontally for fixing the boards and battens, which will be 1x10s and 1x3s respectively.
Having done some studying of product specs, it seems that I would be best off if using a wrap like Greenguard Raindrop or Tyvek Drainwrap. Both these are ribbed with ribs rigid enough to resist crushing. I'll not need to kerf or bevel the furring.
If you can put one of these two expensive rainscreen wraps on sheathing, then nail up FC or wood claps, and the rainscreen permits drainage, why wouldn't it do the same when furring is fastened on?
Window and door sizing and placement, all carefully done when doing plans, then careful layout before nailing up verticals, all this to have batten placement as regards opening trim all work out well, takes more time on these things that plain old claps or shingles ever did.
Has anyone done B&B with a random arrangement of, say, 10 and 12 inch modules, so that this is a little easier to do in the field?
Just curious, do you have exterior sheathing with these smartframe walls? If yes, then why not use one of the rainscreen wraps w/o the furring? Is it to get a thermal break?
>>10 and 12 inch modules, so that this is a little easier to do in the field?
There's a house near mine that's done that way. They milled all the siding from trees onsite, the sawyer made all the boards he could regardless of size, the owner used 'em all. Super rustic looking, they did a corrugated metal roof too. Looks good to me. Not so hard to get battens to all fall under the windows etc. if you do a little layout first on a piece of blue tape running across the wall. Cheat a little here and there and it all fits...
re: 10 and 12 inch random modules...
it will work - cheating an inch or two will not show/detract - just stand a board up either side of each opening and then fill in the field - if you need to spread the boards an inch or rip the boards an inch it will be fine - I make sure to use the same spacing above and below any window -
a couple other details to be aware of -
1) I cut the bottom of the boards @ 45* to form a drip edge - also the battens -
2) carefully plan the nailers - use robust material/fasteners or the boards will pop the battens when they try to cup in the sun - also plan for the trim - I have dealt with situations where the top nailer would catch the board, but was not broad enough to catch the top end of the batten after the horizontal trim was nailed up under the eves - likewise above and below windows -
Gene, I have used the Tyvek "wrinkle wrap" with horizontal furring strips. It works fine.
What detail are you using at the bottom of the B&B? That is area I have seen the most problems with, both on the siding and beneath it.