The natural construction of wood flooring means that there must be gaps between the boards. No matter how tight a fit, there will always be a gap (albeit minuscule) between each plank. This is actually essential to allow for the ‘breathable’ aspect of solid wood to take place. Wood will naturally expand and contract due to climactic conditions, so a certain amount of manoeuvrability is necessary. But if a floor has significantly large gaps between the boards, or if these spaces become wider as the floor ages then it is time to do some plugging and fill those gaps.
Particularly large spaces between floor boards are often the cause of annoying squeaks and groans, as well as being draughty and energy inefficient. In addition to spaces between the boards there may also be gaps between the edging boards and the wall that can look unattractive as if the floor does not quite fit the room.
The way forward
The best way to deal with gaps is dependent upon the type of floor installed. For example, if the wood planking is not permanently attached to the subfloor below then it may be possible to manhandle the boards into place. This being the case, it is better to commence at the edge of the room moving the boards back flush with the wall or skirting.
A good way to avoid a repeat performance of moving planks is to secure them with wooden pegs. These are fairly unobtrusive and easy to install. Another way to avoid plank movement as well as lengthening the life of the floor is to lift rather than drag furniture across the floor.
Assuming the gaps are either too large for the above solution to be effective or if they are particularly persistent they can be filled by the application of filler strips, a dust/resin filling or by plugging the gap with an acrylic filling product. All of these products are available off the shelf at DIY outlets and are not difficult to use.
These are thin pieces of wood that match the colour and texture of the floor. Place these into the gaps and, as long as they are not too small, they will sit on the spars snugly between the planks. The closer the wood match the less noticeable they will be.
This is the best method for plugging gaps that are 5mm or smaller. Mix some same-coloured sawdust with clear resin filler to a putty-like consistency and apply in the gaps using a spatula or putty knife.
Coloured acrylic filler
This is the most effective solution for a perfect colour match the one which will dry most quickly. The biggest challenge with this method tends to be getting the shade just right, so it is always a good idea to try out a colour test before sealing up the floor. However, because this mixture is thinner than the dust/resin filler it can tend to fall through the gaps. If the floor continues to move after treatment the acrylic filler will not hold and the spaces will reappear. On a more positive note, acrylic filler is a smooth mastic solution and will not require sanding.
If either the filler strips or the resin are used the filled areas will required to be sanded and refinished to match the rest of the floor. If the floor is in good condition this can be undertaken with either an orbital sander or sandpapering by hand but if the floor is dull and becoming rather lifeless it could be an opportunity for a thorough floor sanding and refinishing.