Replies

1. 
   andy_engel | Sep 13, 2021 06:39am | #1

   I'd use regular old #15 felt. Ideally, I'd also add horizontal nailers to create an airspace, but that's probably belt and suspenders.

2. 
   florida | Sep 13, 2021 08:50am | #2

   As Andy said, felt is fine. Make sure the felt and siding come past the old siding by about an inch so water doesn't wick up.

3. 
   sawdust_steve | Sep 13, 2021 09:51am | #3

   You dont say what kind of board and batten you are using. Is it traditional wood material? If so I'd prefer the air gap option. If you dont use nailers at least use a drainable housewrap (like Benjamin Obdyke)

4. 
   eddo234 | Sep 13, 2021 10:10am | #4

   One problem with a rainscreen for board and batten, or any vertical siding, is simply using horizontal nailers creates rows and rows of places to trap any water that gets behind the siding. One option if you go with a rainscreen (which is a good idea) is to use Coravent’s rainscreen for vertical siding: https://www.cor-a-vent.com/sturdi-battens.cfm I’m a fan of 15# felt, or even 30#, in this situation.

5. 
   rrock | Sep 13, 2021 12:06pm | #5

   Thanks to all that have commented, the information provided is extremely helpful. I’ll be using cedar that my dad cut on his portable mill. Sounds like most are for felt and rainscreen/nailers. Thanks for providing product names and links to the cor-a-vent product. I also like the drainable house wrap option from Benjamin obdyke. Going to check with my local supplier to see what they have available. Thanks.

6. 
   tfarwell | Sep 16, 2021 08:17pm | #6

   I did this to my house - I'm looking at it now from my deck. Here is what I did:
   - #15 felt
   - Vertical 1/2" plywood battens nailed over it into the studs to make a gap for a rain screen. I bought damaged plywood for this and ripped it into 2" wide strips.
   - Bug screen at the bottom (I use cora-vent) and at the top. I hid the vent at the top behind a piece of trim, so you can't see it from ground level. Also, I have pretty good over-hangs.
   - "Board" wood nailed to the strips. I ripped rough-face plywood into 11 3/4" wide boards for this. Z-flashing between any boards that ended up being on top of each other. I chose to do this rather than just put large sheets of plywood up, since I wanted it to look authentic. Leave a 1/4" gap between them.
   - Battens nailed over the gaps. If I need to continue a strip, I cut them at 45 deg where they came together to shed water
   - PL caulked the corners between the battens and the boards to keep the water out.
   - Painted it.

   8 years later it still looks new.

   I noticed a significant improvement in the insulation after I did this, even with vents at the top and bottom. It inhibits convection against the main wall structure. Also the exterior plane gets warm in the sun, and the chimney effect keeps quite a bit of heat from transferring inwards. Also, nailing the battens over felt that's over the T-1-11 helps with air sealing.