How do I prep a wood deck that still has peeling semi-transparent stain in Ottawa?

Proper deck prep in Ottawa requires removing all loose and peeling stain before applying any new finish, as our freeze-thaw cycles will quickly destroy a coating applied over compromised surfaces. Start by power washing the deck with a fan tip nozzle to remove dirt, mildew, and loose stain, then allow 48 to 72 hours of dry weather for the wood to fully dry before proceeding with further prep work.

Ottawa's extreme temperature swings cause semi-transparent stains to fail by losing adhesion to the wood substrate, creating the peeling and flaking you're seeing. This is especially common on south and west-facing deck surfaces that take the most UV punishment and thermal cycling. The key is getting down to sound, adhered stain or bare wood before applying your new finish.

After power washing, use a stiff-bristled brush or paint scraper to remove any remaining loose stain. For stubborn areas, a deck stain stripper ($25 to $40 per gallon at Ottawa home centers) will soften the old finish for easier removal. Apply the stripper according to manufacturer directions, scrub with a stiff brush, then rinse thoroughly. Some contractors use orbital sanders with 80-grit paper for heavy prep, but be careful not to gouge the wood. Always sand with the grain direction.

Once you've removed the peeling stain, inspect the deck boards for any soft spots, splinters, or damaged areas. Replace any boards that are spongy or severely weathered. Allow the deck to dry completely — typically 2 to 3 days of sunny weather in Ottawa's climate. The wood should feel completely dry to the touch before staining.

Critical timing consideration: Plan this work for late May through September when you'll have several consecutive days without rain. Ottawa's unpredictable spring and fall weather can ruin deck prep work if moisture gets into freshly stripped wood. Never apply stain if rain is forecast within 24 hours.

For a deck showing significant peeling, expect to spend $3 to $8 per square foot on professional prep and restaining, depending on the condition and size. When the prep work becomes extensive or involves a large elevated deck, browsing painting contractors through the Ottawa Construction Network directory can help you find professionals with the right equipment and experience for safe, efficient deck restoration.