WOOD SURFACES
SURFACE CHARACTERISTICS
- Wood is a common building material and is used extensively in house building including doors, window frames, cupboards, flooring, and ceilings.
- Moisture content of wood should be around 10-12% when painting.
- Painting moist wood will result in blistering and flaking.
- Wood moisture can be tested using an electrical conductivity metre.
- Surfaces should be cleared of all contaminants including oil, grease mortar.
- Loose fibre should be sanded off too.
Knotting
- Exuded resin should be removed and the area covered with Knotting Sealer.
Priming
- Priming of Hardwood or Softwoods should be with Sparcolux Paints Wood Primer.
- On site priming should be done by brush and a second coat applied to open grained wood.
- New joinery should be treated with a second coat of primer before fixing, especially in-accessible areas or areas in contact with masonry.
Filling
- After priming, all cracks, holes and open joints must be made good.
- On exterior wood, be sure to use exterior grade stopper or filler.
WHAT TO LOOK OUT FOR:
New joinery
New joinery are usually primed at works, but lengthy delays between delivery and erection can result in moisture uptake, as the primer alone does not provide sufficient protection
Preservative treatment
- Factories typically apply preservatives to protect against timber rot.
- It can be assumed that these treatments can be painted over, unless advised to the contrary.
- Moisture levels need to be checked, before painting.
New unprimed wood
Wood that has not been primed or knotted
Treatment
- Softwoods and Hardwoods: Follow steps above – knotting, priming and filling using Pink Wood Primer.
New primed wood
Wood that has been knotted and primed
Treatment
- Check that primer is in good condition. If not, remove and primer again.
- Follow General Preparation guideline.
Fire retardant wood
Retardants may cause paints to slow dry and guidance should come with the wood as to how best prepare the surface. Follow these guidelines.
Treatment
- For un-primed wood, follow General Guidelines.
Where surface deposits, primer with Sparcolux Paints Bonding Liquid.
Painted or varnished wood
- Old wood that has previously been painted or varnished and currently resides in situ.
- Doors and window frames may need to be removed from fixings for thorough repainting.
Treatment
- Where existing coat is in poor condition, remove completely and apply General Guidelines above
- Where existing coat is satisfactory, clean surfaces and then follow General Guidelines
Creosoted wood
Creosote is a wood preservative that renders the wood a very dark brown or black in colour.
Treatment
- Creosoted wood should NOT be painted, till the creosote is very well aged.
- Some wood preservatives are not to be painted over – check the product guidelines
- Where permissible, prime the wood with Sparcolux Paints Bituminous Aluminium Paint with two coats, before following general guideline above