Wood is a natural product and as such expands and contracts with changes in atmospheric conditions. It is for this reason that wooden floors need an expansion gap. Solid wood floors take in moisture when there is a high level of humidity in the air and let that moisture go when the humidity reduces. High humidity in the wood causes it to expand. Low, or reducing humidity causes it to contract. When the wood expands, it may be that any small gaps disappear but when the wood contracts the gaps will typically reappear. This is entirely normal.
Either way, it is absolutely essential to leave an expansion gap around the perimeter of your room when laying a wood floor. Expansion gaps should be around 15mm to allow the wood to expand and contract without suffering any sort of distortion. If you don’t leave this gap, when your floor expands it could well rise, causing damage.
In a domestic setting, particularly in centrally heated homes, floors expand and contract with the seasons. During winter months, when you switch the central heating on, wooden floors will lose moisture and contract. This contraction is caused by the dryness of the air, encouraging the wood to naturally lose its inherent moisture. The contraction which occurs in the wood during these winter months is highly likely to cause gaps to appear in the floor, which, if not properly insulated may give rise to draughts. In order to avoid this, you should make sure your sub floor is well insulated.
In the warmer months, when the heating is switched off, the wood will expand again. This is caused by the rising moisture in the air which is absorbed by the floor. When this happens, if there have been any gaps over the winter months, they are highly likely to disappear. This natural process of expansion and contraction is unlikely to pose any sort of damage or distortion to your solid wood floor as long as it has been well fitted with the requisite expansion gap.
If you don’t allow for an appropriate expansion gap in your flooring project, the effects could be catastrophic. When a floor expands and touches a wall or door frame (known in the trade as a “pinch point”), there is pressure placed on the boards causing them to rise. Like all things flooring, if you’re in any doubt, your flooring supplier should be able to reassure you.
—
FAQ
1. Why do wooden floors need an expansion gap?
Wooden floors need an expansion gap because wood naturally expands and contracts with changes in atmospheric conditions. High humidity causes the wood to absorb moisture and expand, while low or reducing humidity causes it to release moisture and contract. An expansion gap accommodates these changes and prevents distortion.
2. How large should the expansion gap be when laying a wood floor?
An expansion gap around the perimeter of your room should be approximately 15mm. This space allows the wood to expand and contract without suffering any distortion. Without this gap, the expanding floor might rise and cause damage.
3. How do seasonal changes affect wooden floors in a domestic setting?
During winter months, particularly in centrally heated homes, wooden floors lose moisture and contract due to the dryness of the air. This can cause gaps to appear in the floor. During warmer months, when the heating is switched off, the wood absorbs the rising moisture in the air and expands, likely closing any gaps that appeared during winter.
4. Can the expansion and contraction of a wooden floor cause damage?
The natural process of expansion and contraction is unlikely to cause any damage or distortion to your solid wood floor, as long as it has been well fitted with the requisite expansion gap. Failure to provide an adequate expansion gap could result in the floor touching a wall or door frame when it expands, causing pressure that can make the boards rise.
5. What are the potential consequences if an appropriate expansion gap is not allowed in a flooring project?
If an appropriate expansion gap is not provided, the floor can expand and touch a wall or door frame, known as a “pinch point”. This puts pressure on the boards, causing them to rise and potentially leading to damage. If in doubt, it’s best to consult with your flooring supplier for guidance.