We are really confused. Everyone we speak to has a different opinion. We want to reside our house. We like the look of vinyl siding and will need to remove everything that currently exists on the house (soffits, siding, leaders, gutters, you name it.) 1. I would like to know if the foam back siding is more energy efficient than reg. siding with Tyvek and rigid foam.
2. If I use foam back siding, do I need to Tyvek. Rumor has it that I would be creating sick house syndrome if I did both, but two separate estimates we received included doing both.
What they are thinking is the foam back siding is created a vapor barrier. If you add the tyvek you are adding another barrier (weather barrier) And this creates what they are talking about. But you are not encompassing anything between these barriers, so nothing is wrong with "both" Only advantage of foam backed over foam and siding is one less installation step. If you want more insulating value, you need thicker insulation. So I would reccommend 1" foam board tyvek and siding.
Foam with proper installation and taping all seams is rated as a weather barrier. Foam backed siding offers the same thing. BUT... in many cases it is not installed that perfectly so I would use the tyvek as a safety net.