New bath addition with tile walls inside: What is most foolproof wall assembly?
Will use rain screen approach outside. Will use a layer of 3/4" plywood behind Durock or similar on inside of wall to attach grab bars anywhere in future. Plywood behind wall finish is suggested by various websites for handicap bathroom. Closed-cell spray foam is in budget. Using all pressure-treated lumber. Will use sealants in all appropriate locations to prevent air leaks.
Will install bathroom fan with humidistat.
My concern is the limited drying potential of this wall. I will allow all wood to dry before completing wall finishes using a dehumidifier if necessary. The choices seem to be stud wall with closed cell foam sprayed from inside or 2" EPS outside of sheathing and some cavity insulation. it seems to me that the simple stud wall with rain screen approach might provide some limited drying to the outside through the wood frame. The outside foam might impede the little drying potential that exists.
Floor is suspended concrete slab on an ICF foundation. Roof will be vented, conventional rafters with adequate amount of closed-cell spray foam,
Posted Jun 23, 2014 7:13 AM ET
Edited Jun 23, 2014 9:08 AM ET
Other Questions in Energy efficiency and durability
Detailing flashing, waterproofing, and the various layers of exterior roof insulation and at the valleys and sidewalls