Handling and Storage
It is essential that you unload your wooden flooring in dry weather, never unload
the flooring in the rain as the moisture could cause the planks to warp. Your
wooden flooring should be stored in a dry place at room temperature and if
possible should be raised off the ground (on a palette for instance). You should
store your wood flooring in the room that it will be laid for a minimum of 72 hours
(preferably a week) so that it has time to acclimatise to the moisture and
temperature of the room.
Preparing To Lay Your Flooring
The most dangerous enemy of a hardwood floor is moisture; you must ensure
that the sub-floor (i.e. concrete, plaster or timber) is dry. This is especially true
when laying a hard wood floor in a new build property where concrete floors will
still contain a high level of moisture. Your solid wood flooring should have been
allowed sufficient time to acclimatise to the conditions of the room in advance of
Any timber existing flooring , joinery or battens should have a moisture
content of no more than +2% above the moisture content of the new floor . It is
advisable when laying on to existing timber that you ensure it is treated against
fungal or insect attack. Concrete or screed should contain a damp proof
membrane and have a moisture content of no more than 5%. This is in practice
almost impossible to achieve and so additional precautions should be taken to
prevent moisture reaching the new floor .
Concrete or screed will take approximately 1 day per mm thickness or 1 month
per 25mm of thickness to dry naturally to a moisture content of 5%. The deeper
the concrete slab the longer the period, for example a 150mm slab will probably
take 10-12 months to dry back to a safe moisture level.
The ambient conditions in the room should lie somewhere in the range of 40-50%
humidity and a temperature of 15 to 25°C at the time of laying the floor . Only
order the floor when you are ready to lay it. Under no circumstances store it in a
room that is wet or outside, or even in a garage where it could pick up moisture.
Take the floor into the room in which it is to be laid in the optimum working
conditions and allow it to adjust to the temperature for a minimum of 72 hours –
preferably 1 week. True acclimatisation will take a few weeks and this is best
done after the floor has been laid (assuming correct allowance has been made for
expansion and contraction).
Allowing For Expansion
All wood floors will expand and contract over the course of the year. Typically
hardwood will expand across its width during the summer as the air becomes
more humid and the wood takes in the moisture, and shrink during the winter
when the heating dries out the air and removes moisture from the boards. Kiln
drying to 8-10% moisture content will minimise excessive movement. A gap of
15mm to 20mm should be left around the floor to allow for expansion. However,
a floor laid in winter that will expand in the summer may require additional
expansion to be allowed across the width of the floor .
Recommended fitting methods
All solid floors should ideally be installed by secret nailing to timber (either an
existing floor or battens or plywood laid over concrete). The advantage of this
method is that the boards can be fitted tighter together for a better fit. In
addition, the mechanical fixing of the boards is a long established technique that
allows the boards to expand and contract whilst remaining firmly fixed down.
Should any board begin to move because the sub-floor has moved over the
course of time (for example as new joists continue to dry out) the floor can be
further nailed or screwed down, something it is not possible to do when floors
have been glued.
Gluing directly to concrete is becoming an established method of fixing. Where
this is seen as the preferred option we would still recommend the laying of
plywood over the concrete and the floor being glued and pinned to the plywood.
Any board more than five times wider than it is thick is more prone to bowing and
cupping. Therefore any board over 140mm wide should be additionally secured
across its width either by screwing and pelletting, face nailing or using adhesive
on the back of the board.
In the kitchen, the flooring should be installed under kitchen appliances, but be
very careful when the appliances are moved over the floor . You can use floorprotecting
pads on the feet of smaller appliances to protect your flooring against
scratches and scuff marks.