If you are lucky enough to expose old floorboards in a house you are renovating and decide to reveal them in all their glory, you may find yourself with a bit more than a sanding job on your hands.
In our article on renovating wooden floorboards in this section we concentrated on preparing the surface and sanding back. In this article we’ll go into more detail about fixing any problems that you find with floorboards before you start sanding.
Why Gaps and Squeals Develop
When floorboards were first laid in old houses there was no intention that they should be seen. So as they would be hidden by thick underlay, carpets and rugs to provide insulation from noise and draughts, the craftsmen fitting the floorboards wouldn’t worry too much about knots and splits in the timber.
Over time the floorboards will have moved and warped leaving gaps between them. There might also be other holes from the fitting of heating, plumbing and electrical systems that will let cold air through from the cavity below the floorboards. Warping and lifting of the boards also leads to squeaks and movement underfoot.
Filling in Gaps in Floorboards
Small gaps can be filled quite easily. The traditional method is papier mache (a paper and glue mix) which is pressed into the gaps and left to dry. A more modern option is to mix sawdust with PVA glue. With both these methods the filling medium can be mixed with a wood dye of the correct tint to help it blend in.
Large gaps can be filled with fillets of wood cut from other boards. Spread wood glue over both sides before knocking them down into the gap with a wood or rubber mallet. As it would be nearly impossible to effect a perfectly sized fillet for every gap in a room you are likely to have to follow up with papier mache or PVA glue and sawdust as described above.
Dealing with Squeaking Floorboards
Squeaks develop over time when nails have lost their grip, sometimes as a result of the common (and essential) practice of being knocked below the surface of the floorboard before sanding. Squeaks can also develop in high traffic areas where the action of people’s feet over the years can loosen the grip of a nail.
Many squeaks can be fixed by adding a few more nails. Make sure that they are tapped in at a slight angle and make each angle different to its nearest neighbour. This will make it harder for floorboards to work themselves up again.
Screws for Severe Squeaks
Where a floorboard has warped too much for nails to hold it down then a screw will need to be used. Drill a pilot hole first to avoid splitting the wood and countersink the hole so that the screw head will be drawn below the surface of the floorboard when it is tightened up.
Use a proper wood screw that is tapered along its length rather than a straight screw designed for shipboard and other composite materials. You can also disguise the screw head by spreading wood filler over it. Bear in mind that this will make it difficult to find and unscrew in the future, so perhaps it’s best left uncovered if it’s in an area where it won’t be too visible.
Once you are happy with the condition of the floor it’s time to sand down and varnish or wax to enjoy the lustre of original wooden floorboards.