A. It depends upon the age and type of your floorboards and your skill at carpentry. The wider the boards, the older they usually are. They may also not have been disturbed before, so lifting them is to be avoided or carried out with the utmost care. Other floorboards can tolerate being lifted provided that a skilled carpenter undertakes the work and that the boards are replaced in their original position.
A. Old buildings do need to allow moisture to move in and out of the fabric to keep dampness below the levels at which decay can set in. This means that impervious materials, like metal- foil backed insulation, plastic foams, and waterproof paints, should never come into contact with permeable fabric such as floor timbers and floor boards. There are lots of good alternatives that are 'breathable'.
A. There are several types of materials available that are suitable for use as insulation in traditional buildings. These should have good thermal insulation properties, but should not impair evaporation of moisture or cause it to be held against the building fabric. Mineral wools are acceptable in most situations. Natural fibre based insulation, such as sheep’s wool or hemp/cotton fibre mixes, may be preferred on environmental grounds. For insulating boards use materials like wood fibre- board.
A. The extent and type of insulation that can be provided between the joists will be dictated by the size of the joists. In older buildings these can vary considerably, from as little as 75mm deep to more than 225mm deep or more. Obviously, the greater the depth of the joists the more opportunity there is to provide insulation.
Different insulation materials have different properties so it is always worth checking with the manufacturer or supplier if you have a target standard you wish to meet. The Building Regulations also change from time to time (and vary in the different in the different countries of the UK), so it is worth checking the current regulations.
To meet the current Building Regulation standards in England, a minimum of about 125mm of insulation is required between, above or below the joists. There is flexibility within the Building Regulations to vary the targets for example, if installing big thicknesses of insulation below would limit the headroom in a cellar or so limit the air movement in a crawl space that damp problems may occur.
A. No. The Building Regulations only apply to new building work, so there is no need to upgrade an existing floor to meet the standards if you are not doing work to it. However installing insulation will help save money on fuel bills, increase the comfort of your home, and help reduce the impact you have on the environment.
A. Yes, but insulating a solid floor is a costly undertaking. English Heritage has published a separate information sheet about insulating solid floors.
A. Insulating a cellar is possible, but even more costly than insulating a solid floor. You would need to find out how damp the walls are and come up with a suitable design. You might have to accept that the improvement would be very limited and therefore not worthwhile.
A. Check with your local planning authority’s conservation officer as every building is different. Consent will be needed for any alterations that affect the building’s character.
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