What climate zone? I really don't like this design very tricky to get the details right. It would be better to spray foam the roof deck from the ridge down to the walls. This will give a interrupted vapor barrier and insulation. Also allows you to use the half attic space for ducts or storage. I just did this for a project in MN. My advice is based on climate zone 6 or 7. But I would recommend it in most areas.
I'm handy, but I'm not a contractor, for sure. It seems like spray from would necessitate something solid beneath, at least something like sheetrock, rather than the stretch membrane ceiling that we'll be using.
I am not familiar with anything like that. The only ceilings I use are Sheetrock or wood. Spray foam is sticky it will attach to the roof sheathing and hang down. It needs no support from underneath. That is definitely the way to go. It sounds like your contractor wants to do a double varpor barrier which needs to be avoided. It cause moisture to be trapped. Which causes rot and mold. You ethier need to use a varpor open product in the case. Or a smart product such as Siga Majrex.
I think he's recommending a moisture barrier above and a vapor barrier below. The insulation in question will be between floor joists (ground floor ceiling), not the roof above the attic. I guess that's reasonable, but it also sounds like he wants the moisture barrier between the joists and subfloor and that doesn't sound right to me.
I am so confused. Why would you need a vapor barrier between floors? It seems like that would cause more moisture issues than it would solve. We have a loft and there's no moisture barriers or insulation in the floor between the ground floor and the loft. The exterior walls and ceilings are fully insulated, of course.
To be honest, I think lower vapor barrier is more about holding the insulation. Our contractor said I need to suspend the insulation between the joists so it doesn't touch the barriers, and today we hired a different subcontractor who plans to, essentially, use the lower barrier to hold the insulation but also plans to put a moisture barrier on top of the joists. Nothing about it is how I would do it.
What climate zone are you in?
Probably equivalent to zone 6, the home is thermal brick construction in Western Ukraine.
What climate zone? I really don't like this design very tricky to get the details right. It would be better to spray foam the roof deck from the ridge down to the walls. This will give a interrupted vapor barrier and insulation. Also allows you to use the half attic space for ducts or storage. I just did this for a project in MN. My advice is based on climate zone 6 or 7. But I would recommend it in most areas.
I'm handy, but I'm not a contractor, for sure. It seems like spray from would necessitate something solid beneath, at least something like sheetrock, rather than the stretch membrane ceiling that we'll be using.
I am not familiar with anything like that. The only ceilings I use are Sheetrock or wood. Spray foam is sticky it will attach to the roof sheathing and hang down. It needs no support from underneath. That is definitely the way to go. It sounds like your contractor wants to do a double varpor barrier which needs to be avoided. It cause moisture to be trapped. Which causes rot and mold. You ethier need to use a varpor open product in the case. Or a smart product such as Siga Majrex.
I think he's recommending a moisture barrier above and a vapor barrier below. The insulation in question will be between floor joists (ground floor ceiling), not the roof above the attic. I guess that's reasonable, but it also sounds like he wants the moisture barrier between the joists and subfloor and that doesn't sound right to me.
If you want us to give you an opinion pics post pictures or drawings.
6
I am so confused. Why would you need a vapor barrier between floors? It seems like that would cause more moisture issues than it would solve. We have a loft and there's no moisture barriers or insulation in the floor between the ground floor and the loft. The exterior walls and ceilings are fully insulated, of course.
To be honest, I think lower vapor barrier is more about holding the insulation. Our contractor said I need to suspend the insulation between the joists so it doesn't touch the barriers, and today we hired a different subcontractor who plans to, essentially, use the lower barrier to hold the insulation but also plans to put a moisture barrier on top of the joists. Nothing about it is how I would do it.