The required finishing and maintenance of a project can be hard to determine and predict. At Woodform Architectural, we are often asked questions about the preservation and re-coating of timber. We have compiled a few of these questions to assist you in realising something beautiful that will endure for the long term.
Preserving the natural look of timber and allowing natural weathering is best achieved in one of two ways. Either by using a curing oil with UV absorbers that is regularly maintained, or for a longer maintenance interval, a stain that closely resembles the original colouration of the timber species can be used.
If natural weathering is the desired outcome, great care should be taken when selecting the timber species. It is important to specify the profile and section size, and to design the building so that the “weathering” is even across individual elevations.
So, what are the best quality oils to protect the timber?
Products are available that preserve the timber with a natural un-weathered appearance. These oils cure in the surface of the timber to improve control of moisture vapour transfer. This gives an improved dimensional stability and prevents surface checking and splitting. These oils should also contain a mould inhibitor and some pigment that will remain suspended in the cured film, giving improved UV resistance on the timber surface.
It should be noted that these products need to be regularly maintained in order to retain that ‘fresh’ look. If this look is desired, the client must be made aware of the ongoing maintenance requirements of such a finish.
But what happens if the film coats starts to peel and flake. Even after 3-5 years after initial coating?
Luckily, there are a few things you can do to fix this.
Assess Suitability: We can nspect the degree of deterioration of the existing coatings and determine the presence of decayed timber. Check coating adhesion using the cross-hatch test.
Clean Surface: Clean the surface and remove all dirt, dust and all other surface contaminants. This should be done by using a suitable cleaning agent and then rinsed off with clean water. If there is mould, it should be treated with a suitable mould treatment.
Repair Surface Imperfections: Prepare all areas that have poor adhesion, are cracking, peeling and flaking. Sanding, power sanding, scraping, wire brushing or burning off can achieve this. Feather edges of the surrounding sound paint to completely remove visual ridges and wash or dust off to remove debris. (Any major design faults or decayed timber leading to structural weakness must be corrected prior to repainting.)
Sanding: Sand the entire cleaned surface to an even flat gloss level to provide a smooth, even surface and a good key for the new coating system to adhere to.
Prime: Prime any bare areas with a suitable primer.
NOTE: If you plan on staining the timber it must be sanded back to clean bare and all coatings must be removed.