Garage newbie

[DJ Parker]

Hi all, we’re building a new 2 car slant roof style garage in Tulsa, OK which does have decently cold winters and hot summers. Contracted to leave it unfinished but with moisture barrier and electrical in conduit. Looking for advice on best type of insulation to put in before dry wall and for the roof to avoid moisture problems. Plan to add a wall/window type AC Unit and a separate heater just to use while working in it. So won’t be full time climate controlled, just while working in there to save on energy bills.

 

[u2slow]

I did rockwool and poly VB. Plywood; no drywall.

Drywall can mold. The rockwool cannot harbour mold, which I felt was important as I knew heat would be a ways off, and sporadic. Still no heating or hvac yet (10yrs gone by).

 

[FrancisJ]

As an old "okie" myself (lived in OK City and Choctaw) I'd say it's really important to insulate your garage and I'd spend most of the money at the roof level since that's where the insulation problem is the biggest challenge (windows and doors are next). You have three options generally insulating at the roof per the building science folks: https://www.greenbuildingadvisor.com/article/three-ways-to-insulate-the-top-of-the-house

Another type of insulation to use in addition to the above is a radiation type barrier -- heat travels three ways: conduction, convection and radiation. Typical insulating approaches (the above from the Building Science article) are heavily focused on convection mitigation, to a lesser degree on conduction, but few if any address radiant heat losses during winter or infiltration during summer. I use the NASA developed "thin layer" insulation to tackle the radiation problem IN COMBINATION with the other approaches above: https://www.lowes.com/pd/Reflectix-...p.ds&msclkid=f47a4d862d2019db4b1e2adbb7b1b3e5