Wood preservative

Wood that lives outdoors, in pergolasPergolaAn open shade structure in a garden, on a terrace or a roof, made of posts and beams with slats, reeds, fabric or plants on top. It is often made of wood., shutters, doors, railings and planters, gets wet, dries out and bakes in the sun. Left unprotected, it turns grey, cracksCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention. and, wherever it stays damp, starts to rotWood rotDecay of wood caused by fungi when it stays damp for a long time. Rotten wood goes soft, gives when pressed or crumbles, and can't be saved with paint. or gets woodworm. A wood preservative penetrates deep into the fibres and protects it from within.

It is brushed on, or the wood is dipped, while the wood is clean, dry and bare, before primerPrimerThe thin first coat that goes on before the main material. It binds dust, seals the pores and helps paint or waterproofing stick firmly., paint or varnishVarnishA clear or semi-transparent finish for wood that lets the grain show through and protects it from sun, rain and wear.. The places that soak up the most water, such as cut ends, the feet of posts and joints, need particular care. There are clear preservatives and tinted ones that add colour at the same time.

A wood preservative does not replace the final finish, and it cannot save wood that has already rotted; rotten wood is cut out or replaced. Most preservatives contain active chemicals, so they call for gloves, good ventilation and care around plants and pets.