Why Is The Stain/Paint On My Deck Bubbling Up After Application?

One common issue with deck staining is that the stain is not durable. Bubbling of new stain can occur if the deck is not prepared and stained properly. The biggest reason that bubbling occurs is that the wood of the deck has too much moisture before staining. If the wood is not dry, the moisture will try to escape when the sun hits it, creating bubbles. Even if the wood looks or feels dry, it can hold moisture for multiple days after rain. Typically, it is recommended to wait 48+ hours after a rainstorm before staining. There are also tools to test the moisture level of the wood. Anything less than 15% is okay to stain, while 11 or 12 percent is typical, and less than that is fine as well. 

A bubbling deck in Verona, Wisconsin. This board may have held more moisture than the surrounding area.

If bubbling does occur, how do you fix it?

If the wood was not properly dried out, and bubbling does occur, the bubbles will need to be scraped and sanded off. At that point, new stain can be applied in those areas until the stain is even and there is no more bubbling. The deck may take a few days of sun to reveal all of the bubbles, so wait a while before fixing the bubbling problems, or there may be more issues that arise. 

Are there other reasons that bubbling happens?

Bubbling can also happen if the stain/paint is applied in high temperatures. 90℉+ can cause the stain/paint to dry too quickly and potentially bubble. To prevent these issues, avoid staining during the hottest part of the day. Additionally, if a deck isn’t prepared properly, dirt, algae, or other grime can create bumps or bubbling. To prevent this, make sure the deck is cleaned well so that the stain or paint can properly adhere to the wood.

Summary

Bubbling usually comes down to moisture, heat, or poor prep. Give your deck plenty of time to dry, avoid staining in hot direct sun, and start with a clean, well-prepped surface. Taking these extra steps will help your stain or paint go on smoothly and last for much longer than it would otherwise.