Installing Your Own Hardwood Floor
Please note: we’re not actually recommending that you do this on your own! This post is more to show you the work that is involved and the steps that your installation company should be taking. We hope that once you’ve read the information below you’ll agree that this is a job for a professional.
When it comes to hardwoods, installation typically falls into one of three camps.
Nailed Down: used for semi-solid floors, over an existing sub floor that is also wood, most commonly plywood or floorboards
Glued Down: used for semi-solid or engineered floors that are laid over plywood, chipboard or concrete
Floating: also used for semi-solid or engineered floors that are laid over any suitable substrate (including concrete, plywood, chipboard or floorboards)
Nailed Down Installation
STEP ONE: First, the door liners, doorstops and any other internal decorative elements should be undercut, so that once the floor is laid it will fit snugly at the new height. For the same reason, doors should also be removed, trimmed and re-hung.
STEP TWO: In addition, as in the UK the floor will expand and contract during the course of the year, the floor needs to be laid with what is known as an ‘expansion gap’. The size of the gap will vary, but it is typically 1.5mm per metre of length (or width) – and the gap must be left clear around the whole floor. It is covered either by pinning what is called a ‘trim’ in a matching hardwood to the existing skirting boards, or by removing the skirting boards altogether and fitting the new ones above the new floor.
STEP THREE: The floor should have a random pattern of joints, and the way this is usually done is to lay the planks in rows and then use an off cut from the end of each row to start the next. It’s recommended that no end join is within 15cm of another, and that – if end joints are to be level at all anywhere in the floor – they have three rows between them.
STEP FOUR: When nailing the boards down to the sub floor, use 50mm nails and drive or fire them at a 45 degree angle through the ‘tongue’ of the board into the sub floor. Nails should be placed 25-30cm apart, taking care to keep them further than 5cm from the end of the board to prevent the wood splitting.
Glued Down Installation
STEPS ONE, TWO & THREE: As above, any doors, door frames etc should be cut down so that they will fit over the new floor, and an expansion gap should be catered for. The same rules about joints apply.
STEP FOUR: An MS Polymer adhesive should be used that: contains no solvents (as these could spoil the wood finish); contains no water (which could make the wood swell); keeps its elasticity when cured (dried); and is compatible with underfloor heating. The adhesive is actually put down on the sub floor, and the planks or boards then laid over it.
STEPS ONE, TWO & THREE: These are the same as they would be for either nailed or glued installations, as explained above.
STEP FOUR: If your sub floor is a concrete or screed one you need to stop any residual moisture from damaging your floor; use 1000 gauge plastic sheeting as a barrier before putting down a suitable underlay. Joints need to overlap by at least 20cm and be taped too. Place PVA adhesive inside the tongue and groove joint, and while it is drying make sure that the expansion gap is filled with spacer blocks so that the planks are held together firmly.
Even if you have carried out these steps to the letter, unless you have used a hygrometer to check the moisture levels at the installation site and are sure that your chosen floor can withstand them, then it could buckle or crack. If in doubt, always consult an expert.