Solid Wood Preparation and Installation Guide Solid wood flooring is by nature structurally more unstable than engineered wood flooring.  This is because all the grain is running in one direction and is not counter-balanced in any way.  For this reason, Crown Classic recommends that all our solid wood flooring is permanently fixed to the subfloor.  There are three main types of subfloor encountered in the domestic market: Wooden Subfloor/Floorboards If the existing floorboards are level, sound and with no lateral movement then a new solid floor can be fixed directly over the floorboards by secret nailing.  However, it must be installed at a 90º angle to the existing floorboards to prevent the possibility of joints lining up.  Look for signs of mould, fungi and rotten timber in existing floorboards.  These boards would need to be treated or replaced before any works can commence.  If there is movement in the floorboards they need to be firmed up by additional fixings or packing out the joists.  If uneven, they can be sanded to level or alternatively ply can be laid over the top, fixed at 4” centres with ringshank nails or screws, with the new wooden floor laid over in any direction – again being fixed by secret nailing.  Always check the moisture content of the plyboard – which should be between 9-11%.  Chipboard Subfloor Crown Classic does not recommend fixing a new wooden floor directly on to chipboard subfloors as they are prone to movement.  Crown Classic recommends fixing ply at 4” centres, again with ringshank nails or screws, which will firm up the subfloor and the new solid floor can then be laid using secret nailing. Crown Classic also recommends that protimeter readings are taken in the area in which the flooring is to be installed to check the following:  Air temperature – ideally between 18ºC and 23ºC  Air humidity – ideally between 45% and 60%  Subfloor moisture content It is also important to check that the air flow beneath a wooden subfloor is free and not blocked in any way. Of course, Crown Classic Solid Oak is also load-bearing and therefore can be laid as replacement floorboards and secretly nailed directly on to joists of fitted on to battens. Concrete Subfloors It is important to check any subfloor prior to installation.  When fitting to concrete subfloors, always check the following:  Degree of level (BS8204) – SR1 + 3mm over 3m.  Moisture content - must not exceed 2.5%.  For anhydrite subfloors, the moisture content must not exceed 0.6% (rarely found domestically). A newly poured subfloor requires a drying time of about 1 week per cm depth up to 5cm and 2 weeks per cm after that.  For example, an 8cm subfloor requires 11 weeks of drying time prior to installation of a wood floor.   Laitance (crust formed on top of floor – tap with hammer to see if it breaks up – remove if present)  the subfloor is free from contamination, eg., floor paint, adhesive residue, etc. Also, check the temperature and moisture in the air, as before. To ensure the subfloor is fit for purpose, CQFS recommends:  Applying a liquid Damp Proof Membrane, eg., 2 x coats F Ball F76  Applying 1 x coat neat primer, eg., F Ball P131  Applying a minimum of 3mm of a water-based/acrylic based levelling compound, eg., Stop Gap 100 or 200 (do not patch screed or pour less than 3mm as it will not be strong enough to hold the wood down).  If any other levelling compound is to be used, ensure it reaches more  25 Newtons in strength at 3mm thickness. Crown Classic recommends that a trowelled adhesive is used as it gives a greater coverage and surface contact, eg., B93 single component polyurethane. General Installation Guidance Always acclimatise any wood flooring in the area in which it is to be installed for a minimum of 2 days (packaged and laid flat in the centre of the room). Whenever installing new solid flooring, always leave an expansion gap of 8-10mm around the perimeter and any static object, eg., radiator pipes.  These expansion gaps can be covered using skirtings/scotia and radiator rings.  It is recommended that a break is left between rooms as there can be a difference in temperature and humidity from room to room.  This difference could cause the flooring to expand and contract at different rates.  Without a break, this may cause the flooring to lift or tent away from the subfloor. End joints should be randomly staggered by 30cm or more to prevent a brickcourse appearance.  It will also aid the strength of the floor.  It is also recommended that the installer works from 2 or 3 packs simultaneously to ensure an even appearance and that each plank is visually checked before installation.       Home   Products   Maintenance   Installation and Warranty   FAQs   Headlam Group Directory   Contact Us              Home   Products   Maintenance   Installation and Warranty   FAQs   Headlam Group Directory   Contact Us