How often a deck needs refinishing in southeast Alberta sun

Deck finishes are rated on the assumption of average exposure. We do not have average exposure. Horizontal boards in this part of the province take more UV than almost any surface in the country.

Horizontal is the hard part

Vertical surfaces shed water and take glancing sun. Deck boards take it square on, hold standing water, and get walked on. The same product that lasts six years on siding will be tired on a deck in two or three.

A realistic cycle

• Clear or lightly tinted finishes: one to two years on the boards.
• Semi-transparent stains: two to three years.
• Solid stains: longer, but they fail by peeling rather than fading, which means stripping rather than recoating.
• Railings and vertical faces: often double the life of the boards.

The test

Splash water on the boards. Beading means the finish is working. Soaking straight in and darkening means it is open, and open wood in our sun greys fast.

Decks in the newer parts of Medicine Hat — Ross Glen, Southridge, Southview — sit open to the south and west with little mature shade, and they weather faster than the ones tucked into the older treed lots down in River Flats and Riverside.