Overcoming 2 by 4 walls

[Deleted member 45]

The shed i will finish out has 2x4 walls. Going with 2x6 would raise price quite a bit. And really 6 inch walls are not much better for insulation......
To remedy the lack of room for insulation, i plan on using polyiso foam board over studs, and r13 to beef up the R numbers on walls
For ceiling i will stick Radient Barrier against roof rafters. Foam board on top of ceiling rafters, more r13 inbetween and possibly more foam board instead if paneling or drywall. The foam board is paper or foil faced, so painting is the cheap option
Everything goes back and forth on my plans, determing Cost-to-Benefit. More insulation is a upfront cost vs. a life cost of heating and cooling over years

 

[Deleted member 45]

Expanding foam in a can, is not my friend. There is a fine art to applying that stuff. Go too fast and you dont get enough, cross the fine line of not too fast/ not fast enough and you get this

 

[markedbrav0]

The shed i will finish out has 2x4 walls. Going with 2x6 would raise price quite a bit. And really 6 inch walls are not much better for insulation......
To remedy the lack of room for insulation, i plan on using polyiso foam board over studs, and r13 to beef up the R numbers on walls
For ceiling i will stick Radient Barrier against roof rafters. Foam board on top of ceiling rafters, more r13 inbetween and possibly more foam board instead if paneling or drywall. The foam board is paper or foil faced, so painting is the cheap option
Everything goes back and forth on my plans, determing Cost-to-Benefit. More insulation is a upfront cost vs. a life cost of heating and cooling over years

Smart approach! I've been learning a lot from this forum! Have you considered sealing all seams with foil tape? I heard it makes a noticeable difference in keeping drafts out.

 

[m4ri0o_th]

The shed i will finish out has 2x4 walls. Going with 2x6 would raise price quite a bit. And really 6 inch walls are not much better for insulation......
To remedy the lack of room for insulation, i plan on using polyiso foam board over studs, and r13 to beef up the R numbers on walls
For ceiling i will stick Radient Barrier against roof rafters. Foam board on top of ceiling rafters, more r13 inbetween and possibly more foam board instead if paneling or drywall. The foam board is paper or foil faced, so painting is the cheap option
Everything goes back and forth on my plans, determing Cost-to-Benefit. More insulation is a upfront cost vs. a life cost of heating and cooling over years

Good decision with the polyiso over the studs! That continuous layer of foam board is key to reducing thermal bridging, which is where heat easily transfers through the wood. Adding that layer will make a big difference, even more so than just using 2x6 walls with no exterior foam.

For the ceiling, I'm not sure what you mean by a radiant barrier on the roof rafters and then more insulation on top of the ceiling rafters. But I think you either create an unvented roof assembly by installing all your insulation directly against the underside of the roof deck, or you can go with a traditional vented attic space where the insulation sits on top of the ceiling with a gap for airflow above it. A radiant barrier only works when it has an air gap. Then for sealing smaller gaps, consider using a high-quality tape or caulk! Hope this helps and keep us updated!

 

[sansf0rgetica]

The shed i will finish out has 2x4 walls. Going with 2x6 would raise price quite a bit. And really 6 inch walls are not much better for insulation......
To remedy the lack of room for insulation, i plan on using polyiso foam board over studs, and r13 to beef up the R numbers on walls
For ceiling i will stick Radient Barrier against roof rafters. Foam board on top of ceiling rafters, more r13 inbetween and possibly more foam board instead if paneling or drywall. The foam board is paper or foil faced, so painting is the cheap option
Everything goes back and forth on my plans, determing Cost-to-Benefit. More insulation is a upfront cost vs. a life cost of heating and cooling over years

How's the foam board holding up with paint? Any peeling or warping over time? Also, for the radiant barrier on the ceiling, did you notice a big difference in heat during the day?

 

[Titotoby]

That's a good plan actually, polyiso over the studs will kill a lot of thermal bridging, I'm here asking myself why that didn't come to mind and combining it with batts gives you good bang for the buck. Just watch your moisture management with all those foil faces so you don't trap condensation. The ceiling sounds fine too, extra foam up there will pay off more than anywhere else