Existing Floor Coverings
Materials such as vinyls, lino, ceramics, and floor paints can be left in place, subject to conditions and suitability. Normayyl no treatment is required for floating floors.

Cement
Concrete or screed doesnt require special treatment, although moisture levels discusse earlier can affect the laid floor.

Wood
Examples include T&G boards, wood block, chipboard, plywood, and MDF etc. Cleaning, priming, and/or sanding may be necesary before a new fullyt adhered floor is laid.

Joists and Battens
Batten centres depend on the end use of the floor. Generally 400mm for domestic installations.

The premesis containing the wooden floor must be weather tight, and have a dry stable temprature and humidity. Heating and ventilation can also be influencing factors.

Tempreature and Humitity
At the time of installation, the relative humidity (RH) of the air should be within the expected RH range of the building when in use. Ideally this should be between 35% and 65% RH. For best results, the range of RH should varymore than 30% during the life of the floor. The building should be in alived-in condition. All wet trades such as plaster and subfloors should be fully dried and cured long before the wooden floor is laid.

Damp
Exposure to dampness will cause serious prblems to a wooden floor and can prove very costly to rectify. Damp issues must be rectified prior to any installation. This may require advice from a damp proofing specailist, but ask the manufacturer first, who may have a solution.

Storage
Lenghty storage times should be avoided. If storage is necessary, good dry and stable conditions are essential. In such cases timber planks should be stored flat and properly supported along their length. It is also wise to protect floors where necessary as unprotected floors can be scratched, market, and damaged.

Maximum Surface Temperature: The maximum surface temperature should be 26C-27C. Most timber boards are ideally suited for under floor heating due to their low moisture content.

Heating Systems to be Operational: It is important that UFH systems are in operation prior to the installation of a hardwood floor, especially those systems installed within screeds, and that the room temperature is between18C-22C. Commonly, the system will be switched off a day before installation and turned back on gradually after the floor has been installed (1 degree C per week as a rule of tumb).

It is also recommended that the heating system runs for two weeks to avoid moisture problems. However do not fix the floor and then start up the heating system, this will drive the moisture into the underside of the boards.

Once the species of wood, grade, thickness, and method of installation have been chosen, the area to be floored should be checked for the following points.

1.Site conditions
2.Type of sub-floor
3.Sub-floor with Under Floor Heating (UFH)
4. Moisture content of sub-floor

Moisture is one of the most common causes of failure in wooden floors, so the following points should be carefull noted.

Cement Bases: Concrete will take an average of 3 months to dry: 6mm per week or 25mm per month. Maximum 5% moisture content or 75% relative humidity. These are figure that indicate moisture content of the sub-floor prior to the laying of flooring. water used in the construction of a cement base must be allowed to dry out.

IT IS THE RESPONSIBILITY OF THE FLOOR LAYER TO MEASURE THE MOISTURE CONTENT OF A FLOOR. IF IN DBOUT - DO NOT LAY!

Residual Moisture: Requires a surface membrane. Even with the above levels, there is always residual moisture trapped in the base, which will never come out. However small levels may come out in the future. As a result all timber floors laid on a concrete/cement base require an underlying moisturre memberane on the surface of the base.

Measuring Moisture Content
There are two methods of measuring the moisture content of a sub-floor are the Electronic and Hygrometer (more reliable). The Hygrometer method is the only accepted standard (BS 8201) and should not exceeed 75% RH.

In general screeds require one month per 25mm to fully dry, however does nto apply to screes exceeding 75mm in thickness.

Drying Different Concrete Types

Concrete: Moisture can be trapped due to constituents of the mix, how much water was used in the mix and the thickness of the concrete.

Power Float: This will take longer to dry than a rough tamped finish, due to the relatively dense sealed skin that forms on the surface.

Sand/Cement Screed: Dries fairly. The drier the environment, the quicker a cement base will dry. if the RH of the air is more than75% RH, the drying time will be longer.

Wooden Sub-Floors: Moisture content of joist and battens; is important that the moisture content is between 12% or below.

Suspended Wooden Floors: Void underfloor is to be vented as current building requlations require. This is good practice as putting a moisture membrane on a wooden sub-floor can be detremental to the wooden floor is not properly ventialted.

It is of the utmost importance that the corrcect and adequately suited flooring product is selected and specified before a timber floor is laid. This avoids future problems with the installed floor.

What is the primary use of the floor?
Wood floors installed in commercial areas such as restaurants will receive far more wear and tear than those in residential areas such as bedrooms. Futhermore areas such as hallways in residential areas will receive more wear and tear as a result of traffic than those in bedrooms.

The following should be considered when selecting a wooden floor.

• Is the floor likely to be subject to heavy wear and tear?
• Is the floor for sports, multi purpose, domestic, or commercial use?
• Will the floor receive regular and correct maintenance?
• What type of maintenacne is currently available?

  Timber floors are generally not recommended for bathrooms or other wet areas. However, they are often used in kitchens and other areas where minor spills may be expected. In such cases, the client must always be informed of the need to wipe up spills immediately and to have a suitable maintenance programme.
  
  The choice of species will also play in the selection, as some woods are harder and denser than others. Woods such as oak, are traditionally the most suitable.
  
  End user/customer expectations of flooring
  Wood is a natural material and is therefore subject to infinite variations in colour, texture, knots, and grain pattern. Natural timber also contains characteristics such as surface splits and shakes, these are accepted as being a normal feature of wood and are not detrimental to the performace of the floor. The level and volume of natural characteristic of wooden flooring is knon as the 'grade', a clean grade will have minimised amounts of knotsand mineral streaks, whilst a rustic grade will usually ahve an abundance of knots, mineral streaks,and grain variations to add character.
  Wood flooring move by expansion and contraction as a result of tempreature changes in a room or area, this is normal behaviour for wood as it is not an inert material.
  
  Determining which floor to select
  The floors selction will be determined by its use.
  
  Domestic Floors
  1. The required look and colour of the floor, as wellas its use.
  2. Ease of maintenance is important.
  3. Thickness is less important as wear is minimal.
  
  Commercial Floors
  1. Aesthetics play a great part in the selection.
  2. Long term durability will be required.
  3. Easr of cleaning and maintenance costs.
  4. Speed and ease of installation.
  5. Durability of species and grade.
  
  Cost
  Wooden floors are very cost effective, when long term maintenance and durability are taken into account. Unlike carpets and other surfaces, real wooden floors can be easily refurbished to provide brand new surfaces time after time, year after year.