What is the recommended or code requirement for finishing the bottom edge of exterior rigid insulation?
Ron Lay| Posted inBuilding Code Questionson
On the exterior of my home I plan on using 1/2″ OSB, 1″ rigid insulation, with 1×4 furring strips (and insect screen) creating a drainage plain, covered by fiber cement siding. I wonder if the fire code deals with this specifically or not? (Leaving the bottom edge and the drainage plain open to the bottom side.)
You have really the best articles dealing with exterior insulation and drainage plains, but I don’t recall seeing if leaving the bottom edge exposed is OK or if it is better to put a drip rail under it, or what some other solution might be?
Thanks
rlayhouse
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Check out theslideshow.net search OSB rot.
Then think about using Zip R-sheathing, with 1" of foam safely tucked inside your wall. Seal the rest of your frame properly, flash your windows and doors properly and you will have a great build IMO.
Much less to deal with than your posted specs. IMO.
Try it, Mikey likes it, and now aj does too
Ron,
Here is a link to a video that shows you how to trim the exposed bottom edge of the rigid foam with metal flashing:How to Install Rigid Foam Insulation Outside a House.
If not sheathed choose Zip R-sheathing. You will eliminate many labor steps along with whatever mistakes the trades will build in.