There are plenty of exterior coatings available. Sadolin Superdec has a combination of features that makes it particularly useful for exterior timber as well as other substrates. It’s self-priming and undercoating on timber, so in many situations there is no need to work through separate primer, undercoat and finishing products. One of the best examples we’ve seen is this striking blue house. An experienced trade customer used it extensively across the exterior.
Rather than looking at a sample board, this project gives a better idea of what can be achieved on a real property. It shows how dramatically exterior timber can be transformed with colour.
But appearance is only part of the story.
Exterior timber naturally expands and contracts as temperatures and moisture levels change. Superdec is designed to remain flexible, helping the coating resist cracking, peeling and flaking as the timber moves.
It is also vapour permeable, allowing moisture vapour within the timber to escape rather than becoming trapped beneath the coating.
Then there is drying time.
The latest Superdec formulation is touch dry in approximately 1–2 hours and recoatable after around 6 hours at 20°C and 65% relative humidity. Sadolin gives a spreading rate of up to 14m² per litre on smooth planed timber.
Real-world drying times will naturally vary depending on temperature, humidity and the surface being coated, but the relatively quick recoat time can make Superdec particularly convenient for exterior maintenance and renovation projects.
Don’t Forget the Prep…
Sadolin Superdec may be straightforward to use, but straightforward does not mean preparation can be skipped.
If an existing coating is sound, preparation may simply involve cleaning the surface thoroughly and lightly abrading it before re-coating.
Loose, flaking or failing coatings should be removed, while grey or weathered timber needs to be sanded back to clean, sound wood. Any mould, algae or other organic growth should also be properly treated and removed rather than simply painted over.
Sadolin recommends that timber is suitably dry before coating, with a moisture content of no more than 18%. Untreated exterior softwood may also require a suitable wood preservative before the decorative finish is applied.
There is another useful point to bear in mind if you are working with white or pale colours. Resinous knots and some timbers can cause extractive staining to show through the finish, so a suitable blocking primer may be required in these areas even though Superdec itself is normally self-priming.
Ultimately, Superdec is designed to make the finishing stage straightforward — but the condition of the surface underneath will always determine how much preparation is needed first.
How Does Sadolin Superdec Perform?
If you would like to see how Superdec stands up to the seasons three years on, we did go back and
re-visit this house. Head over and see what we found.
Our Woodcare experts are always on hand for help and advice. Give them a call today – 01303 477555
