Solid hardwood floors, as any regular reader of this blog will know are floors that are made from planks that are cut from one single piece of timber. They may be made of oak, ash, pine or walnut, but the difference between solid wood flooring and engineered wood flooring is the construction of the plank. Solid wood flooring is a completely natural product that has minimal interference from man, whereas engineered wood flooring is a combination of natural products that are bonded together to create a stable and strong board.
Solid wood flooring has been used for structural purposes for centuries and there’s no reason why that should stop now. In old buildings that are hundreds of years of age, you’ll often typically find the original solid wood floor that has been laid over the beams or joists, as they are known. Effectively, the solid wood flooring is laid perpendicular to the beams in order to create the floor of the room in question. The fact that solid wood can be used for this purpose hasn’t changed over the years, but for speed, skill and cost reasons, in many instances this style of construction is no longer used. Modern day building techniques tend to rely on concrete as the subfloor of choice, over which an engineered wood floor will typically be laid.
All of that said, there is a tendency across the globe right now for people to seek out traditional construction methods and to update them to make them more efficient from a heat loss point of view prior to adopting them in the building of their homes. This is often seen where houses have a basement for example and it is feasible to lay solid wood boards directly over the beams that will make up the ceiling of the basement and the room immediately above.
If you are planning to use solid wood flooring as structural boards, there are several things you need to bear in mind:
- You need to make sure that the joists aren’t too far apart. Generally speaking the rule of thumb is that to correctly support a solid wood floor, joists should be no more than 450mm apart. If your joists are further apart than this there are two potential solutions. The first is to cover your joists with ply or chipboard (see point number 5. Below); the second is to introduce noggins and, or braces to support your floor. Put very simply, noggins are pieces of wood and braces are pieces of steel. Both noggins and braces can be placed between joists to provide additional support, allowing hardwood flooring to be fitted straight to joists and ensuring a stable end result. Which option you decide upon will depend entirely on your own situation and if you are in doubt, you should seek expert advice before laying your floor.
- You should establish that there are ventilation points in the space between the floor and the ceiling below. This is important from an insulation, comfort and economical point of view. What you are looking for here is reassurance that there is no increased risk of dampness and that air can pass through the space.
- It is important to determine a suitable method of insulation, particularly if your floor is to be laid over an unheated space eg. a garage or a cellar. If your floor is being laid over a heated space however, you may well decide that it is best not to insulate the space to enable warm air to pass from the room below.
- It is a good idea in certain circumstances to consider the introduction of either a plywood or chipboard subfloor, which will make your finished floor more stable as well as removing any doubts about the spacing of your joists.
- You should choose a solid wood flooring board that is at least 18mm thick if you are planning to use it as a structural board, 20mm even better. Any thinner and you could face problems.
If you are thinking of investing in a solid wood floor and want to fit it directly over joists, why not contact us for some advice? We have many, many years of wood flooring experience and will happily share that with you in order to help you make the right decisions for your project.
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FAQ
What should be the maximum distance between joists when installing solid wood flooring as structural boards?
The rule of thumb is that joists should be no more than 450mm apart to correctly support a solid wood floor. If your joists are further apart than this, you can either cover your joists with ply or chipboard, or introduce noggins and braces for additional support.
Why is it important to have ventilation points between the floor and the ceiling below?
Having ventilation points between the floor and the ceiling below is crucial for insulation, comfort, and economy. It helps to avoid the increased risk of dampness and ensures that air can circulate through the space.
How can I insulate a solid wood floor laid over an unheated space?
Insulation is particularly crucial when your floor is laid over an unheated space, like a garage or cellar. However, specific methods of insulation can vary depending on the situation, and seeking professional advice may be beneficial.
When should I consider the introduction of a plywood or chipboard subfloor?
It can be advantageous to introduce a plywood or chipboard subfloor in certain circumstances. This can make your finished floor more stable and remove any doubts about the spacing of your joists.
What should be the minimum thickness of a solid wood flooring board used as a structural board?
You should choose a solid wood flooring board that is at least 18mm thick if you plan to use it as a structural board. Opting for a 20mm thickness can offer even more stability.