Over time, timber collects the patina of age on its surface and may show the marks of the craftsmen who originally worked it. This adds character, atmosphere and style, not to mention a sense of history to a home, so it’s important to think before rushing to treat, strip, coat or repair old timber.
Dealing with Decay
- What causes timber decay? Dampness. This leads to rot or beetle infestation or a combination of the two and, in structural timbers, this can be disastrous.
- How should decay be dealt with? Investigate and understand the cause of the dampness, then rectify the problem. This may simply be a blocked gutter, leaking pipe, or because the timber is in contact with a damp surface. Once the timber has dried out, further rot or insect attack will be limited.
- Is beetle infestation always a worry? Virtually every old building has evidence of beetle attack – usually the common furniture beetle (woodworm) or deathwatch beetle – but much of this is likely to be historic so of little concern. Active beetle infestation is revealed by fine dust or ‘frass’ left behind by the beetles as they eat their way to the timber’s surface and create holes.
- Are chemical treatments needed? Randomly sprayed chemicals tend to deal with the symptoms of the problem rather than the cause, are expensive and unpleasant to use. For active woodworm, localised and targeted application of insecticides to the affected areas may be justified.
- How can I test the condition of timber? Prod with a penknife to determine what’s going on below the surface: if there’s resistance to the blade, the timber may be sound even if the first few millimetres have been affected. If in doubt about structural timbers, consult a structural engineer.
- What was the traditional way of finishing the oak beams of timber frame buildings? Often both the internal and external timbers, along with the surrounding infill panels, were given a coat of limewash. This is the ultimate breathable and traditional paint.
- Where repairs are made, should new timbers be stained to match the old? At first new timber will look very raw, but oak, in particular, will take on an attractive colour and becomes darker with age, so it’s generally best to avoid using wood stains.
- How can weatherboarding be protected? Flexible vapour-permeable finishes, available in a variety of colours, are ideal as they allow for movement and the escape of moisture. Where new timber is being used it’s worth giving it at least one coat before it’s fixed, to prevent the problem of uncoated areas being revealed should the timber move. Without treatment, sweet chestnut and oak will mellow to an attractive silvery-grey.
- Should linseed oil be used to enhance the appearance of timber? No, linseed oil used on wood tends to stay sticky so attracts dust and dirt and discolours over time. Beams tend not to need treatment but you could apply a beeswax polish.
- How can dark beams be lightened? Try using a proprietary liming wax or, for an opaque finish, a casein-based paint.
- What finish is best for old floorboards? Homemade beeswax polish was traditionally used. Where a floor is taking a lot of traffic it may be better to use a proprietary blended beeswax which contains a hardener, such as carnauba wax, for greater durability.
- How should I finish unpainted joinery? Varnishes, oils or waxes can be used depending on the finish required. Some come in a range of shades.
Stripping Old Finishes
Stripping off old coatings is sometimes necessary where inappropriate finishes have been used or where successive layers are obscuring the detail of mouldings. Remember, though, that the ‘stripped pine’ look is historically inaccurate because softwood was invariably painted and only expensive hardwoods like oak and mahogany were left bare. There is no magic recipe for removing finishes but ‘Removing Paint From Old Buildings’, published by The Society for the Protection of Ancient Buildings (SPAB), offers advice. Always test a small inconspicuous area first and never use blow lamps, grit blasting, grinding or other abrasive methods which will destroy the timber’s surface.
Make Your Own Beeswax Polish
Beeswax polish can be made by grating a lump of beeswax into a jam jar and covering it with pure turpentine. Leave it to stand overnight and then shake well. The turpentine will dissolve the wax to produce a good polish. If the timber has worm holes, make the wax to a thinner consistency so it can be brushed into the wood, as it will help consolidate the damaged area. For waxing, use less turps to create a stiff polish to apply with a soft cloth. Several coats may be required. Never apply thick coats of wax, as it will remain soft and look dull.