Floors in art deco house should be checked for borer and other damage, and will benefit from underfloor insulation.
Another problem is that repeated sanding over time may have exposed the tongue and groove joint. Damaged boards should be cut out and replaced with new timber.
To repair damaged boards:
- lift individual boards and replace with matching boards sourced from a demolition yard
- a whole floor in poor condition can be lifted and replaced with a new floor
- install a flooring overlay over the existing floor.
If repiling is to be done through holes cut in the floor, the boards can be preserved intact by removing four or five rows of boards for their full length and replacing them on completion.
If a timber floor is in good condition, it can be sanded and polyurethaned to give a durable finish.
Corrosion of nails
Rust may chemically attack timber around corroded fastener – referred to as ‘nail sickness’. It presents as, for example, the dark staining around nails in old floorboards, and although it is unsightly and indicates a slightly weakened part of the timber, it does not generally pose a structural risk in floors (Figure 1).
If the floor is uninsulated, it will be beneficial to install polystyrene or bulk insulation suitable for use in subfloor spaces. Where foil has been installed, it is beneficial to remove the foil and replace it with insulation. Be extremely careful with existing foil insulation because it may be electrically live if a steel fixing has gone through a live electrical cable. Several people have died from electrocution by contacting live foil. Look at NZECP 55 (NZ Electrical Code of Practice 55) for guidance on removing or working around existing foil insulation. Installing and repairing foil underfloor insulation was banned on 1 July 2016.
Reducing subfloor moisture can also make the house feel a little warmer by keeping the air dryer.