A wooden balcony or deck is the hardest-working surface of your home: direct sun, rain, snow and foot traffic. Stain protects wood against water and UV, but it wears off. How long it lasts depends mostly on the type of stain and on exposure.
Types of stain and how long they last
Transparent. It shows all the wood grain but contains few pigments to block UV. Expect roughly 1 to 2 years before the next coat.
Semi-transparent. A good compromise: you still see the grain, with more protection. Often 2 to 3 years on a balcony.
Solid. It covers like paint and lasts the longest, especially on vertical surfaces like fences and railings. On a floor people walk on, it wears faster and can peel in places.
Whatever the type, horizontal surfaces wear faster than vertical ones: a balcony floor will need attention before the spindles do.
The water drop test
Pour a few drops of water on the floor. If the water beads, the stain is still protecting. If it soaks in and the wood darkens, the wood is drinking water: it is time to restain.
Preparation is half the job
Stain applied on dirty or greyed wood does not penetrate well. We clean the wood, remove the grey surface fibres and sand as needed. The wood must be dry before application. New pressure-treated wood often needs time to dry before it accepts stain: the water drop test helps here too.
A trap to avoid
You can go from a transparent stain to a more opaque one without trouble. The reverse, however, requires fully stripping the old stain. Better to choose well from the start.
When to do it?
Ideally in late spring or summer, in dry weather, once the wood has had time to dry after the snow melts. Your balcony is then ready for the whole season.
