Solid hardwood floors have been around for many years. However, more and more manufacturers are switching to wood-engineered floors for various - good - reasons.
This chapter will highlight issues you have to note when purchasing and installing solid wood floors to make sure you end up with the best result possible
Recommended measurements of Solid floorboards and some important rules
Rule of thumb: the width of a solid board should never be wider than 10 times the thickness of the board.
- 20mm thick means 200mm wide maximum, 15mm thick means 150mm wide maximum.
- 'Oversized' boards are very prone to buckle and cup.
Rule of thumb: the location of the Tongue and Groove should be as close to the centre as possible to give the board the best stability. Sold floors with the T&G below the centre are prone to buckle and cup.
The reason given for why the T&G is almost at the bottom of the board: floor can be sanded many times more might sound valid, running the risk of cupped boards before there is ever a need to have the floor sanded outweighs this 'benefit' many times over.
- they are wider than 100mm,
- if the room is not wider than 5 - 6 meter
- and in cases with random length: maximum 15% of the boards are of 'short' lengths - see the article "Three Things DIY Stores Won't Tell You"
Rule of thumb: overall solid floorboards will expand and shrink more than wood-engineered boards. To allow this movement you have to calculate the correct expansion gap needed (and don't fill this gap with cork or anything else!).
Oak floors: for every meter width of the room leave a 4mm gap with a minimum of 10mm. A 2 meter wide area means 10mm gap; a 3 meter wide room needs a 12mm expansion gap.
Make sure your skirting board are thick enough to cover the movement of shrinkage as well - we recommend 18 - 21 mm thick skirting for solid floors.
Pine boards: 4 - 5mm per meter
Beech - a rather 'nervous' wood type - floors: 7mm per meter
Rule of thumb: moist content of a solid Oak floorboard must be between 8 - 11% when it arrives in your home. Leave solid floors - in their packaging - to acclimatise to your house climate for at least 1 - 2 weeks if they are supplied by a reputable company. (Will you ever know where your floor has been stored when you buy of Ebay?)
Take note in which season you are installing the floor:
winter, when your house climate is rather dry due to central heating effect, add 2mm extra to your calculated expansion gap
Late summer/autumn, when your house climate has a high humidity, your floor will shrink more when the heating season starts, this is a normal effect but don't reduce the standard expansion gap for this reason. It's better to add 2mm to your skirting board thickness (if you need to buy new ones - alternatively use flat beading to cover expansion gaps and leave skirting boards in situ).
General advice: keep the width of solid boards narrow, 150 - 160mm tops, for the best and trouble free result. If you fancy a wider board do select wood-engineered, much safer bet and in the end exactly the same look - you only see the surface of your wood floor - which with wood-engineered floors are definitely from solid wood - anyway.