Wood Treatment & Preserver

Wood treatments and preservers protect timber against rot, fungal decay and wood-boring insects, and many add colour and weather protection at the same time. This category covers clear and coloured wood preservers, shed and fence treatments, concentrated fence treatments, oil-based creosote substitutes and woodworm killers.

Types

• Clear preservers: soak into bare wood to guard against rot, decay, woodworm and blue stain, and are used as a pre-treatment before paint, stain or varnish. Leave the drying time on the tin before overcoating.
• Coloured preservers and shed and fence treatments: colour and protect rough sawn garden timber such as fences, sheds and trellis in one product.
• Creosote substitutes: oil-based treatments that give a similar look and water repellence. Traditional creosote is restricted to industrial and professional use and is not sold for use at home.
• Woodworm killers: fluids brushed or sprayed onto infested timber.

Before you treat

Cut out and replace any rotten wood and let damp timber dry first. Small round flight holes do not always mean live woodworm: the attack may have died out long ago. Fresh bore dust around or below the holes, or dead beetles, point to a live attack. Keeping timber dry is the main defence, and where structural timbers such as joists or roof timbers are affected, have them checked by a qualified surveyor before you treat.

Safety

Read the label before use, and never pour leftover product down a drain or into a watercourse; dispose of it as your local authority advises. Follow the manufacturer's instructions and safety data.

For other exterior finishes, see wood care; for clear protective coats, see varnish.