Rain Screen material options
MarkM3
| Posted in Green Products and Materials on
I see a lot of different products commercially available to create a rain screen – basically a gap between the external sheathing and the siding. But why would I not do something simple/cheap like ripping 1/4″-1/2″ pressure-treated plywood into ~2″ wide strips, and nailing those up in line with my studs for my rain screen spacers? What benefits do I gain from buying a more complicated product? Separately, I still need to think through the correct kind of “bug filter” at the bottom – this is where a commercial product makes sense to me – I appreciate any recommendations on that. Thanks much, Mark
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Replies
Mark,
Lots of people rip plywood into furring strips to create a rainscreen gap. That option is listed in my 2013 article, All About Rainscreens.
In that article, I wrote, "For thin furring strips, you can use 1/4-inch lath board or rips of 1/4-inch plywood. If you want a deeper gap, just use thicker plywood."
I also wrote, "Furring strips don’t have to be pressure-treated, because a rainscreen is designed to stay dry." So save yourself some money by using ordinary CDX plywood instead of pressure-treated plywood.
If you read the article, you'll find more useful tips.
Thanks very much, Martin.
Mark,
Reasons to use a manufactured product include
• time (faster to install)
• more even surface for install (better finished appearance, prevents waviness that you can see with furring strips)
• in cementitious veneers (stucco, thin stone) there is an attached fabric to keep mortar from blocking the air gap
Very much appreciate your input, Tyler
I'm looking for tips with using 1/4" thick plywood furring strips to create a rain screen gap with SIPs. I'd be attaching these strips to the OSB layer on the outside of existing SIPs. What screws are recommended for such an application? We will be attaching cedar clapboard siding to these strips. Also, with only a 1/4" thick gap, neither of the Cor-A-Vent products seem to be a good match (thicknesswise) to go at the bottom of each "bay". Do you think it would be reasonable to use about 4" high of copper mesh (such as https://www.amazon.com/Stuf-Fit-Copper-Mesh-Birds-Control/dp/B0001IMLTY), or similar height of Benjamin Obdyke 6mm Slicker, at the bottom of each bay, between the furring strips, to keep out ants/bugs/grass? Would I use screening in addition to that material?
Happy New Year everybody! Thank you for all your good input/work/support!
William,
You can use 1-inch long screws to attach the 1/4-inch furring strips to the OSB.
I'm not aware of any specific product to use for screening at the bottom of a 1/4-inch-deep rainscreen gap. But ordinary insect screening will work.
William,
The problem with a 1/4" rain-screen gap is that the house-wrap or building-paper on your SIPs will never be entirely smooth, The wrinkles both impede the air-flow and end up touching the siding creating a bridge in what is intended as a capillary break. If you can I would recommend a thicker furring.
We generally use 3/4" material. This allows you to use a U-shaped perforated flashing at the base into which you slide the furring, making the installation go easier.
Happy New Year to you too!
Mark,
For a thorough discussion of some of the issues raised here, see this article: All About Rainscreens.
For retrofit, where thickness can't be added, how about using heavy landscape fabric? That should allow some slow airflow, and it's cheap and easy to get. Your thoughts?
Keen now has an .013 inch thick rainscreen premade.
Bryce,
I would stick with products designed for use on walls. There is no reason to experiment with landscape fabric when so many housewrap products -- everything from wrinkled wrap to dimpled wrap to plastic mesh products -- are available.