# Are smart vapor retarders (Class II/III) sufficient behind tiled showers in extreme climates?

**URL:** <https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977>\
**Category:** Trade Talk\
**Created:** [August 4, 2025, 3:18pm UTC](https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977 "2025-08-04T15:18:11Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![reno\_questions](https://home.renovation.reviews/user_avatar/home.renovation.reviews/reno_questions/32/2758_2.png) [@reno\_questions](https://home.renovation.reviews/u/reno_questions)\
**Post date:** [August 4, 2025, 3:18pm UTC](https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977/1 "2025-08-04T15:18:11Z")

</div>

Are smart vapor retarders (Class II/III) sufficient behind tiled showers in extreme climates?

---

<div class="post-metadata">

**Author:** ![Tim\_Michael1](https://home.renovation.reviews/user_avatar/home.renovation.reviews/tim_michael1/32/6294_2.png) [@Tim\_Michael1](https://home.renovation.reviews/u/Tim_Michael1)\
**Post date:** [August 13, 2025, 8:42pm UTC](https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977/2 "2025-08-13T20:42:20Z")

</div>

Smart vapor retarders help keep moisture in check, but don’t count on them to fully waterproof tiled showers, mainly if you live where the weather’s rough. Think of them as one piece of the wall, not the only thing keeping water out.

---

<div class="post-metadata">

**Author:** ![Bobby\_Michael](https://home.renovation.reviews/user_avatar/home.renovation.reviews/bobby_michael/32/2057_2.png) [@Bobby\_Michael](https://home.renovation.reviews/u/Bobby_Michael)\
**Post date:** [August 13, 2025, 8:55pm UTC](https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977/3 "2025-08-13T20:55:33Z")

</div>

Smart vapor retarders, specifically Class II or III, can be sufficient behind tiled showers in extreme climates, but their effectiveness depends on various factors.

---

<div class="post-metadata">

**Author:** ![Tim\_curtis](https://home.renovation.reviews/user_avatar/home.renovation.reviews/tim_curtis/32/2766_2.png) [@Tim\_curtis](https://home.renovation.reviews/u/Tim_curtis)\
**Post date:** [August 13, 2025, 10:14pm UTC](https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977/4 "2025-08-13T22:14:10Z")

</div>

No  
Smart vapor retarders alone aren’t enough behind tiled showers in extreme climates; you need a true waterproofing layer (membrane or board) at the shower side, with the vapor retarder placed so it won’t trap moisture between layers.

---

<div class="post-metadata">

**Author:** ![Theodore\_3456](https://home.renovation.reviews/user_avatar/home.renovation.reviews/theodore_3456/32/2821_2.png) [@Theodore\_3456](https://home.renovation.reviews/u/Theodore_3456)\
**Post date:** [August 13, 2025, 10:37pm UTC](https://home.renovation.reviews/t/are-smart-vapor-retarders-class-ii-iii-sufficient-behind-tiled-showers-in-extreme-climates/19977/6 "2025-08-13T22:37:31Z")

</div>

No

in extreme climates, a smart vapor retarder alone isn’t enough behind tiled showers. Use a waterproof/vapor-tight layer right behind the tile instead, and skip the rear vapor barrier to avoid moisture traps.