unfinished cedar, toung n groove 1/4" thick planks on a bathroom ceiling

Questions From Our VisitorsCategory: Sealersunfinished cedar, toung n groove 1/4" thick planks on a bathroom ceiling
nick lombardi asked 10 months ago

Hi William Stewart,
Small 5′ x 10′ bathroom ceiling with shower and ceiling exhaust fan. Shower is used every day.
Going to install 1/4″ tongue/groove cedar planks over painted sheet rock. Planks are unfinished and more yellow in color than the standard red/brown… I’d like to maintain the yellow color.
2 questions please:
1. Is there a low sheen water based polyurethane product that will seal these and not have an obnoxious odor?

2. And if so, can I only seal the edges and room side surfaces but keep the up side natural in order to use construction adhesive to aid in installation?
~great site,
…..nick in navarre fl

1 Answers
William Stewart Staff answered 10 months ago

Hi Nick,

A water-based satin polyurethane is ideal for your application. Water-based polys don’t change the color of the underlying timber in the way oil-based polys do.
Water-based products also have a lower VOC content than oil-based, so while you will get a smell until the poly cures, there will be no further smell once fully cured. The advantage of water-based polys is that you can use the room two to three times faster than if you’d used oil-based.

Yes, it’s better only to seal the wet-facing surfaces. It also helps the construction adhesive achieve good adhesion. I like to let the wood breathe, and given that it’s cedar, it won’t be a problem with the upper surface not being polyurethaned.

A typical poly I’d use is here: https://geni.us/h0OR
Glad you like the site and good luck!