Staining pressure treated wood

Pressure treated wood is kiln-dried wood (usually spruce or yellow pine) that is pressure-treated with chemical preservatives dispersed in water. The wood cells become saturated with water in the process that can take up to six months to dry out. When the wood is dry, it can be painted or stained like any other wood surface.
Pressure treated wood that is not painted or stained will weather, crack, and check as badly as untreated wood over time.

How to prepare your pressure treated wood

Allow the wood to dry throughly before staining or painting. You can test dryness by sprinkling water on the surface. If the water soaks into the wood, then it’s dry and ready to be coated.

Proper surface preparation is very important. Clean and sand before applying any exterior coatings. Sand along the grain and use proper sandpaper grid: coarser to strip off old coats and medium for smooth surface. Stain can be applied with a brush, roller or sprayer. Check manufacturers label for more information on application.

Paint or stain

From wood enhancing clears to deep colours, there’s a wide variety of finishes for your pressure treated weathered wood on the market.
Transparent finishes range from a clear finish that allows the wood to gray naturally, to a slightly tinted finish with a hint of colour that accentuates wood grain and its natural appearance while offering some UV protection.

Select a semi-transparent/ semi-opaque stain to add more colour and UV protection while still showing the natural grain variation and wood colour.
And finally, solid colour stains provide an opaque finish that showcase the texture of the wood while completely hides the grain and its natural colour.

You can use a semi-transparent exterior stain if you want to keep more of the natural look of the wood or a solid stain if you want more of a painted, solid look in a variety of colours.
Ensure you choose premium quality products like Flood stains (recently re-branded by PPG into Dulux Wood Stains), Olympic and Sikkens.
Good quality exterior paint can be used for vertical pressure treated wood surfaces but for decks, it is recommended to use solid stain for a bolder, painted look rather than exterior paint.

Exterior colours and how to choose your stain

Semi-transparent stains come in a wide variety of colours from pine and natural to teak and charcoal. Most of the semi-transparent coatings will “borrow” the wood tone reason why it’s not a very good idea to try achieving a light colour on dark wood. Please check labels carefully for more specific applications.

Transparent stains come in fewer colour choices mostly natural and will slightly tone your wood. Choose same colour as your existing or a tone darker for a fresh, natural look.

Solid stains can be any colour either custom or catalogue colour: off white, beige, blue, green, chocolate or rustic red just to name a few. Not all colourants are made equal so when choosing solid colours it’s best if you pick through the exterior brochures from the manufacturer rather than going for a random colour that might be prone for fading over time.

When to re-coat

The re-coating interval depends on product recommendations, on average 3-5 years on decks and 5-10 on fence for a good brand. Surface preparation is the key to long lasting results. Other coatings are recommended for maintenance only and will only last for a year or two (Messmers brand for example). Check with the manufacturer before you decide on a specific product.

Safety tips

Wear gloves while handling treated wood and applying stains.

Always wear safety goggles and dust mask when cutting, drilling or sanding.

Happy painting!