Gaps between floorboards are one of the most common issues in period office buildings, and they can be filled without replacing the floor.
Gaps between the floorboards are one of the most common issues in period office buildings, and the good news is they can be filled without replacing the floor. Filling the gaps cuts out draughts, stops dirt and debris collecting in them and gives the floor a smarter, more finished look. It is usually done as part of a sand and refinish, using either a resin-and-sawdust filler for finer gaps or matching timber slivers for wider ones. For an older London office, it is a quick win that makes the whole space warmer and tidier, and it is a routine part of our office floor restoration work.
Gaps are a natural result of age. When floorboards were first laid, decades or sometimes a century ago, they sat tightly together. Over the years, the timber slowly dries out and shrinks, and modern central heating speeds that up by pulling moisture out of the wood. As each board shrinks a little, a gap opens up between it and its neighbour. In a period building with original boards, this is almost inevitable, and it tends to be worse in rooms that are heated hard through the winter.
Open gaps are not just cosmetic. The most noticeable problem is draughts: cold air rises up through the gaps from the void below, which makes a room harder and more expensive to keep warm. In an office, that is a comfort issue for the people working there and an energy cost for whoever pays the heating bill.
Cold air rises through the gaps from below, making rooms harder and more expensive to heat.
Gaps collect grit and debris that is awkward to clean out and works its way down into the void.
A floor streaked with dark open lines never looks fully restored, however well the boards have been sanded.
If you are coming to the end of a lease, there is a practical reason too. Worn boards and open gaps can both appear in a schedule of dilapidations, so filling and restoring the floor can help you meet your handback obligations. We cover that in more detail in our guide to gaps and board damage in a schedule of dilapidations.
There are two main methods, and the right one depends on the gaps themselves.
For fine and medium gaps, we use a resin filler mixed with sawdust taken from sanding your own floor. Because the filler is made with the floor's own timber dust, it colour-matches beautifully, and the result blends in rather than standing out. It is worked down into the gaps, then sanded back flush as part of the refinishing.
For wider gaps, a better approach is to insert thin slivers of matching timber, cut to fit and glued into the gap. These wood fillets are more stable than filler in a large gap, and because they are real timber they look right in a period floor and last well. It is more painstaking work, but for wide gaps it gives the best and most durable result.
In both cases, the filling is done hand in hand with sanding and finishing, so the floor comes out as one even, sealed surface.
Timber never completely stops moving. In a building with big swings in heating and humidity, a filled floor can still see the odd hairline gap reopen as the boards expand and contract with the seasons. It is worth knowing that going in. The timber-sliver method copes with movement better than filler, which is one reason we recommend it for wider gaps, and we will always give you an honest view of how your particular floor is likely to behave before we start.
A quick note on parquet
Everything above is about plank floorboards. If your period office has block or herringbone parquet rather than planks, parquet floors are a different job again, with their own repair and restoration needs. The principle is the same though: the original floor can almost always be restored rather than replaced.
If the floorboards in your office are letting in draughts or collecting dirt in the gaps, filling and restoring them will make the space warmer, cleaner and far smarter. We offer free, no-obligation surveys across London and the Southeast, and we will recommend the right filling method for your floor. Call 0800 917 7770 or request a quote.
