Replies

1. 
   iLikeDirt | Oct 26, 2015 08:39pm | #1

   I live in a house with fiberboard sheathing from the early 1970s. Termites won't touch it. They will eat the studs it's nailed to instead. If it gets wet it won't rot or grow mold. Again, the studs around it will deteriorate instead. It is mildly insulating, too: about R-2.5/inch. The stuff is basically sawdust glued together and impregnated with so many chemicals that it's barely a wood product anymore. It won't hold a nail or a screw and damages easily--it's much less durable than plywood or OSB. More modern stuff may be slightly better on that front but it will still never match plywood or OSB for physical durability.

2. 
   BillDietze | Oct 26, 2015 09:45pm | #2

   Search with Google (or whatever) for "structural fiberboard sheathing".

3. Expert Member
   MALCOLM TAYLOR | Oct 26, 2015 09:47pm | #3

   Nate,
   That's the only type I'm familiar with. We used to use Tentest in party walls in the '90s. Hard to nail, crumbles in your hands, won't even hold staples. I just wondered if there were some types that, while not structural, could work as a legitimate alternative to OSB or plywood. If it's all like Tentest, I don't see the point of using it at all.

4. Expert Member
   MALCOLM TAYLOR | Oct 26, 2015 09:58pm | #4

   Thanks Bill, I see Georgia Pacific makes one that with some intensive nailing meets code for structural bracing, but at the same time isn't rated to have anything mechanically fastened to it. Just wondering if anyone had any experience using fibre board in their builds.

5. 
   BillDietze | Oct 26, 2015 10:49pm | #5

   Malcolm, here is some mention of some builds using fiberboard sheathing - not sure if they are structural.
   https://www.greenbuildingadvisor.com/blogs/dept/musings/visiting-passivhaus-job-sites-washington-state
   http://zehnderamerica.com/wp-content/uploads/2014/01/pr_2012_06.pdf
   You're right about the intensive fiberboard nailing pattern.

6. Expert Member
   MALCOLM TAYLOR | Oct 26, 2015 11:55pm | #6

   Bill,
   There was an interesting quote in the last link you posted:

   "I’ll be looking at other sheathing materials for my next Passive House project."

7. GBA Editor
   Martin Holladay | Oct 27, 2015 07:21am | #7

   Malcolm,
   Here is a link to a GBA article (you should also read the comments posted below it) with lots of information on fiberboard sheathing: The Klingenberg Wall.

   Several builders have had problems with fiberboard sheathing, and GBA has reported on these problems.

   In an article I wrote in 2011, I reported, "According to Mark Dixon, one of the builders on site when we visited, the fiberboard wall sheathing was unable to resist the pressure of the dense-packed blown-in fiberglass insulation. After the insulation contractor finished insulating the walls, the fiberboard had bellied out and was bulging as much as 3/4 inch in some stud bays. The workers eventually managed to force the bellies back, at least partially, but the experience revealed one potential drawback of fiberboard sheathing."

   In an article I wrote in 2012, I quoted Chris Corson, who said, “On some projects we’ve used high-perm fiberboard for exterior sheathing. It’s made in Canada, and it’s expensive. It worked; it did its job. But it’s difficult to work with. It’s hard to install. It’s dirty. It smells like asphalt. When we started installing the cellulose insulation, it really bellied out. Fortunately we caught the bellying before it became a big problem. We finished the job by watching it closely and babysitting the insulation contractor.”

8. Expert Member
   MALCOLM TAYLOR | Oct 27, 2015 11:25am | #8

   Thanks Martin. It was being mentioned here so often, I thought that perhaps we were talking about some other new iteration of what up to now I've found a very annoying product.
   Edit: My God I'm getting old. I must have read that article. I have posts in the comments section!