Pole building insulation
Hello All,
I recently had a very basic pole building completed. It’s a 24 x 40 x 14 with metal roof, metal siding, concrete floor, 4×6 laminated posts on 8′ centers, engineered trusses, 2×3 or 2×4 girts, one insulated bay door and insulated one man door. My question is with insulating the walls before I put sheathing on the interior walls. I’ve seen a lots of posts about doing spray foam or batts of different variety’s. I was curious if I could use 9′ wide Tyvek in the cavities in between the posts stapled to the girts, one of the 2×12 truss carriers, and posts then taped to make a nice air barrier. The area between the siding and the Tyvek would allow ample air flow to dry the wall cavity. The sheathing of choice would go on the inside then be painted with latex paint. After this I would fill this cavity with blown insulation of my choosing. I was also thinking at the bottom of the cavity just above the skirt board I would put a horizontal treated 2×6 with rockwool below it touching the concrete. I have poly down under the concrete but if I get some water in the building(highly unlikely) or capillary I want an easy fix. I want the building to be moderately condition so in the summer and winter time I can tinker in comfort. This pole building is located in Delaware. We’re about 50/50 in terms of days that are hot and days that are cold. The attic space has bubble insulation just below the tin with a ridge vent. I eventually plan to insulate that as well. I’ve read a lot of posts on here during the construction of my home and I’ve been appreciative of all the input from building science experts. I can go snap some pics if that helps as well but if you’ve seen one pole building you’ve seen a lot.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Are you planning on stretching the Tyvek 9 feet between vertical supports? If you try to fill that big of a cavity with insulation, the insulation is going to press against the Tyvek and most likely press most of that Tyvek layer against your outer sheathing or siding, thus closing off your air gap. You might be able to stretch some horizontal steel wires across that gap every 8” or so vertically to hold the Tyvek back, but even that is going to expand outward significantly when you fill the inner area with insulation.
I’d try using rigid foam instead, which won’t have the problem with expanding outwards against a non-rigid layer like Tyvek. Rigid foam could also double as your WRB behind your siding.
Remember that pole barns are inherently difficult to air seal and insulate well. There are many threads here discussing this.
Bill
Never even thought of that. I like the idea of foam but I heard it's not very green and also easy to mess up sealing wise. What If I do the Tyvek then sheathing on the inside almost like building a wall in reverse. I'd be curious how cost effective this is though. I should've just built a traditional stick built structure. 😑
Different types of rigid foam have different levels of “Greenness”. XPS is the worst, polyiso and EPS aren’t bad. I’d use polyiso in your application, and I’d try to get reclaimed polyiso if possible.
Martin linked an article that will provide more info and ideas. You’re not the first to want to insulate their pole barn, so there is a good amount of info out there to help you.
Bill
Philip,
You might want to read this article: "Insulating a Pole Barn."
Thank Martin, but I have to have a membership to view that article. I've read a few of the other Q&A's that are similar to my situation and my options are limited I feel. Would you recommend the reverse conventinal wall or rigid foam route?
Thanks All,
-Phil
Phil,
I recommend that you get a 10-day trial subscription the GBA. The trial subscription is free.
Here is the link.