I was describing to a friend yesterday how I was going to put a couple layers of 1" foam board to the outside of my sheathing, then put 1X4 furring strips over the foam to attach my Hardi Plank to. He asked what I was going to do at the corners, and I figured Hardi Trim or whatever it's called to imitate corner boards. The question then came up about how to fasten them. I drew it up to scale today, and with 2" of foam plus the furring strip, that doesn't leave anything solid behind it to attach the corner boards to, unless they are pretty wide. The only thing I could see would be to use 1X6 furring at the corners, so they would be fastened solid, and the the corner boards attach to them. That would also leave a nailing surface for the clapboards adjacent to the corner boards. Is this a workable plan? What do they do on the outside corners of houses with 2 or more inches of external foam? While we're at it- don't the furring strips have a lot of 'bounce' when you nail siding to them with only foam behind them? Or does a nail gun take care of that?
IIRC Hardie calls for solid sheathing behind their product, have you checked their install sheets?
Edit... found the sheet on da computer, never mind, it is not required to be over solid sheathing. You will need wider nailers in corners and around windows and doors for trim. We used Miratek 5/4 trim on a hardi job last winter and were pleased with it, its another low maintenance product. A little easier to deal with than cement boards.
Make an L-shaped plywood piece for your corner furring strip that extends far enough on either with of the corner to be you last furring strip for the siding and a solid nailing surface for the corner boards. Since I love my pocket screw jig, I would use that and exterior grade glue and make them in the workshop. Just make sure you thickness matches that of you furring strips.
Mike
That's a great idea, mike- thanks! I'll be building the barn first, so I'll have shelter for things like that.
What is a pocket screw jig? Sounds neat.
Bruce
Warning- You'll wonder how you ever got by without one! http://www.kregtool.com/
So far I've only used mine for small/furniture type projects, but yeah, it'll immediately become the tool you can't live without. [cool]
Thanks a bunch!
Bruce