Florida bathroom reno - tub/shower against concrete wall and vapor barrier questions - GreenBuildingAdvisor
Summary
A Florida homeowner seeks advice on renovating a bathroom with a tub against a concrete wall, focusing on mold prevention and vapor barrier considerations.
Why It Matters
This article addresses common concerns in humid climates like Florida, where improper bathroom renovations can lead to mold growth. Understanding how to effectively manage vapor barriers and insulation is crucial for homeowners and builders to ensure longevity and safety in bathroom constructions.
Key Takeaways
- Consider the impact of humidity on vapor barriers in bathroom renovations.
- Evaluate whether existing insulation and poly sheeting are appropriate for the climate.
- Understand the importance of preventing mold growth in bathroom designs.
Florida bathroom reno – tub/shower against concrete wall and vapor barrier questions Magnumpl | Posted in General Questions on February 27, 2026 11:37pm Hi. I’m renovating a bathroom in Florida and I’m trying to make sure I’m not building a mold trap which is a common case down here. One wall of the tub area is an exterior concrete wall. The old alcove tub sat right up against it. Above the tub, the wall is furred out, and has fiberglass insulation in between, with poly sheeting on the interior side (right behind the drywall) I was planning on using green/purple, Kerdi membrane over the drywall, then tile. Still not sure how to address the cavity. 1. In hot/humid Florida, does that poly make sense at all? If I’m using Kerdi on the surface, should I remove the poly so the wall can dry, or put it again the concrete blocks, or over furring strips and insulation? 2. Since the tub is basically against the exterior wall, is there any reason to try to add anything between the tub and the wall? Thank you Answer GBA Detail Library A collection of one thousand construction details organized by climate and house part Search and download construction details Join the leading community of building science experts Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field. Start free trial Related Questions Exterior wall behind tub/shower pan Switch near shower & tub Insulating Exterior Brick Wall in Bath...
