All building materials offer some degree of R value or resistance to heat flow, but some are better than others. Drywall, for example, has an R value of approximately R-0.5 for its half inch thickness. This is minimal considering that filling a 4-inch thick wall cavity with insulation increases the R value to approximately R-15.Materials that stop air leaks are called air barriers and are best placed next to insulation. Because drywall is frequently installed against insulation, it can be an effective air barrier.
Regular drywall is a poor insulator. This is because half an inch of drywall only has an R value of 0.45, which is poor. And after that, it is enough to glue the boards with weatherproof adhesive tape to assemble the interior walls with the insulation they need. Seal the foam box to the strut and then place a layer of putty on the perimeter face to seal it against the back of the drywall.
Prioritizing your gutters is also something that is worth it since gutters are mainly designed to keep water away from your home roof and carry it away from the foundation through the downspouts you see on the exterior of your home instead of damaging your interior including the insulation you installed. You can hire a professional gutter cleaning service such as Gutter Cleaning Troy MI to make sure that your gutter will be maintained properly.
To create a good air barrier, the drywall must be hermetically attached to the frame and all possible air leakage points around the holes cut in the drywall must be properly sealed. For example, the image below shows a wall composed of four layers of ½ inch drywall on the inside for aesthetic purposes, actual insulation between the uprights, a ¾ inch plywood coating on the outside, and wood cladding as the final exterior finish. Drywall cannot match the beauty and warm decorative effect of the patterns that wood grain naturally gives to finished plywood boards, especially plywood. And while sanding and patching is often necessary to give drywall an attractive finish, it's not mandatory.
But it's not often that drywall is hung that isn't full of holes for electrical boxes, ducts, windows and doors. Drywall installation also requires additional steps, such as mud, sanding and taping, which makes installing plywood a relatively less cumbersome process. This is because all you need to repair existing drywall is drywall mud, an all-purpose razor, and some adhesive tape.