Whitewood vs. #2 Pine Furring Strips
Theminesweeper
| Posted in General Questions on
If I’m building a rainscreen behind my reverse board and batten cypress siding using 1 x 4 furring strips vertically and then horizontally on top of those, which type of wood would be best? #2 pine or whitewood?
And what type of fastener would be best and will not split the strips? It will have to go through the furring strip(s) and OSB, then into the stud. Ring shank nails? Or screws? I’ve also, come across Passlode Tetra Grip nails which look gnarly (and expensive) but I worry that the gun, even at the lowest setting, would split the furring strips.
**Photo is not mine. Just using it to show an example of what I want to do.
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By "whitewood," I believe you mean poplar, or more accurately, wood from the tulip poplar tree, Liriodendron tulipifera. It is commonly used in the northeast US on higher-end projects as interior trim and sometimes for other elements. In my experience it has little to no resistance to decay.
"Pine" includes many different species and varieties, but if you're in the northeast US, it means eastern white pine. The #2 grade has a few tight knots. It has modest decay resistance. It's also softer than poplar and less prone to splitting when fastening than poplar if holes are not pre-drilled.
Fasteners should penetrate the framing by at least 1 1/4". Regular framing nails might be ok but I would use ring-shank trim nails. The right type of screw would be even better but I don't think it's worth the extra time involved. I don't have experience with the Paslode nail you mentioned.
Thank you. Do you have a recommendation for a wood with more decay resistance that typically comes in furring strips? I've seen people rip plywood but I'm trying to avoid that amount of work and I don't have a table saw. It also seems like plywood wouldn't hold up that well when exposed to water and humidity but I don't know a lot about woods!
Unless you're doing open-joint cladding, which I don't recommend, your battens shouldn't see enough moisture to worry about the species. If you want to be extra cautious, though, you could consider anything with "cedar" in the name, or cypress, or pressure-treated southern yellow pine, or douglas fir. If you use pressure-treated pine, just be sure to use fasteners rated for use with pressure treated lumber; regular fasteners will corrode.
While cross-strapping is best, even with wide boards I would be comfortable with a drainable housewrap (Obdyke's Hydrogap or Slicker Classic) instead. You'll get good airflow behind the face boards and enough open space behind the rear boards that they will be able to dry to the sides.
"White wood" in my neck of the woods (NW Montana) is spruce. FYI
Interesting, around here we call it, "spruce."
Googling "white wood" is interesting. Apparently it's a blanket term for secondary wood, often poplar, but it can be basswood, cottonwood, or pretty much any softwood. I'll stick with more specific terms.
But without cross-strapping the siding would have to be fastened into the OSB where there isn't a stud. Is 1/2" OSB "structural" enough to fasten cypress siding to it?
It might be enough, but you're right--it would be better to fasten to something solid. You could add blocking between the studs; I've done that several times on board-and-batten projects. Or, a clever solution I saw recently--fasten strips of Obdyke Hydrogap or Slicker Classic to the back of each piece of horizontal furring before installation. That allows enough drainage, with airflow coming from the gaps between siding boards.
I think the blocking is what I'm going to do along with Keenes Easy Furr strips run horizontally on the outside. I believe someone at MTI Dry suggested to me to run their corrugated strips behind horizontal wood furring strips, too. Very clever.
Theminesweeper,
Are you sure you need both layers of furring? Reverse board and batten siding creates its own rain-screen. I'd be inclined to leave out the vertical layer, or depending on your climate not fur out the wall at all.
We're in central Arkansas. The batten in this case would be a 1 x 8 and the boards are 1 x 6 that sit over the battens by 1 inch on each side so that it looks like 1 x 6 boards going all the way across. I thought you shouldn't use only horizontal boards because water and air need to get through?
Theminesweeper,
Yes, you are quite right. With that setup, both layers are preferable. I was assuming the battens behind would be much smaller than the boards that sit on them. That's usually the way it is done, to give you the benefit of a cavity, and also save materials.
That sounds like board and batten with fat battens-- nothing reverse about it.
It's reverse because the battens are on the backside.
What makes them battens? To me, you have 1x8 boards and 1x6 battens. You've just changed the names then called it reverse. That's like a double negative. Maybe I'm still missing something.
I don't know if there is an "official" definition of B+B vs. reverse B+B but I think of it as the wider board is the "board" and the narrower piece is the "batten." So in this case, I agree with maine_tyler that this is just board-and-batten with wide battens. But if you prefer to think of it as reverse board-and-batten, that's ok too.
At the boxstore, whitewood can generally mean just about anything. Likely an SPF, unless your in the finish section and, like Michael says, it could be tulip poplar. Not likely for strapping grade though.
I've never understood folks' concern with battens/strapping splitting. Things really only split near the end grain. Short of the most brittle hardwoods, fat fasteners near the ends of board is about the only time I've had issues.
While you're right that the ends are most prone to splitting, there are a lot of ends when wrapping a house. The best results seem to be when the lumber pile has been sitting in the rain so the pieces are wet and moldy. The worst is when they have been inside and are bone-dry. I worked at a prefab plant where we cross-strapped many projects and everything was stored inside and dry. Spruce (what we usually get with SPF) is brittle when dry. Not as bad as hemlock, which splits if you look at it too hard, and better than white pine, which rarely splits.
Good points. Perhaps I was being a bit dismissive. I guess my point is that proximity to the ends and fastener size (assuming no pre-drilling) are likely to be the biggest factors. I often see the width of the board discussed (1x3 vs 1x4) and I really don't think that's much of a factor. Species to some degree but still less so unless using something unusual. But i suppose a dry brittle wood may indeed necessitate staying farther from the ends or pre drilling near ends.