What material is best for furring strips behind Hardie Reveal panels?
espiritiv
| Posted in Green Building Techniques on
Looking for the best material to use as 1×4 furring strips behind Hardi reveal panels? I have been told Douglas Fir is best cost and rot resistant, some say Western red cedar (sounds expensive), Pressure treated wood, or Trex (plastic wood alternative), or of course there is the metal varieties.
One issue is read with PT wood is that any contact with aluminum or other metals causes corrosion so you have to paint over that (more expense)
Cost is an issue so i was going towards the route of doug fir?
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Replies
In a well done rain screen system, the strapping (furring) will be continually air dried, so it will not rot. So many species of wood will work, starting with pine. Fir and cedar will also work, but you do not need to pay a premium for a particular wood.
Our lumberyards here stock 2" plywood strips either PT or non-treated. The problem with solid wood stock I can be that all the fasteners are in the same plane so there is a good chance of splitting, especially with fir.
Hi Malcom,
Wouldnt Plywood delaminate opposed to a solid wood furring?
Has anybody seen splitting of 1x4 Fir? I can imagine it being a possibility with dry wood, but we have tons of fresh green Doug fir in Oregon
I'd say about half the builders use pt and half not. I've heard no reports of delaminations, and it's worth remembering that all residential here in BC uses rain screens. While everyone here uses the 2" strips to install the reveal panels, you might want something wider to give you some leeway in your layout placing the metal trim.
I'd imagine the problem with the fir splitting is more pronounced when the fasteners are closer, with produces like Hardi-boards, but you do see the concern being brought up. I think there was even some comment on it by the architect in the blog on the Orenco Passivehouse project posted here several weeks ago.
Seeing as you are pre-drilling for the fasteners on the reveal panels anyway, splitting probably isn't as big an issue, but anyone who has tried to toe-nail D Fir knows it can be fairly finicky stuff.
Tauran,
Bob is right. You don't need to use pressure-treated wood or rot-resistant species, because rainscreen gaps tend to be very dry. For more information on this issue, see All About Rainscreens.