Making furring strip assembly coplanar over Roxul Comfortboard and irregular sheathing boards
Hi all,
I am looking for a technique to help create a coplanar 1×4 furring strip assembly over 1.5″ Roxul Comfortboard. We have a 120 year old home with 1×12 rough hewn diagonal oak boards patched with 3/4″ plywood where we discovered rotten wood. There is up to 3/8″ variation in the plane from one board to another. We plan to side with 8″ LP Smartside lap siding.
We have ordered 4.7″ Heco Topix Therm screws from Small Planet Supply and are going to loosely follow the following poster’s recommendations but I would love additional comments on anyone who has any experience or thoughts on how to make this job successful.
Thanks in advance,
Bridgette
See below for poster’s rec:
How to not compress the furring strips into the roxul comfortboard and keep it in the same plane
Over drive the screws and then ‘back them off’ so that a ‘straight-edge’ held against each 1×4 strap is perfect from top to bottom. Fashion the straight-edge from a perfectly straight 10 foot 2×4. Drive a 4” nail at one end using it to hook the straight-edge to the top plate or a higher mounted reference. This system proved to be ‘the way to go’ – simple, accurate & fast.
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Replies
Bridgette,
It's a trial-and-error process. Use the straightedge every which way -- vertically, horizontally, and diagonally -- and correct problems as you find them. Tighten the humps and loosen the valleys.
Good luck.
Bridgette, although I have not installed exterior mineral wool myself, I have done a lot of remodeling that included making large, uneven surfaces flat. My approach is to start by getting each end of the area perfectly straight and parallel. Then stretch a mason's stringline very tightly from end to end, with spacers made of 3/4" wood scraps, to get the stringline above the plane that you're trying to flatten. As you adjust each nailer, use a 3/4" scrap to gauge progress. The gauge block is important so you don't get accumulated errors.
MIcheal,
'Preciate it. Will give it a try.
Just a quick update that the Mason's stringline was the most effective approach.
Here's a picture of the finished siding.
2nd try...