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Insulating a loft

FIXING A VAPOUR BARRIER ON THE FLOOR LAYING INSULATION BLANKET ON THE FLOOR INSULATING WITH LOOSE-FILL

FIXING A VAPOUR BARRIER ON THE FLOOR

Things you will need
Tools Scissors.
Materials Rolls of reflective foil building paper or sheets of polythene, masking tape.

1. Cut the material with scissors so that it is about 2-3m (50-75mm) wider than the gap between the joists.
2. Lay the material in the gap, taking care to keep your weight only on the joists. Reflective foil paper must be laid foil-side down.

3. Seal any overlaps in the material with 2in (50mm) masking tape.

LAYING INSULATION BLANKET ON THE FLOOR

The spacing between joists varies but 13&1/2in (350mm) is about average. Do not cut the excess off 400mm blanket, let it curl up on each side to make a snug fit.

Things you will need
Tools Scissors, face mask and possibly protective gloves.
Materials Rolls of glass fibre or mineral fibre blanket.

1. Start unrolling the blanket between two joists at the eaves at one end of the loft.

2. Do not take the material right into the eaves, you must leave a gap of about 2in (50mm) so that air can come in through the soffit and flow through the loft. If the air cannot circulate, condensation may form.
3. Press the blanket down lightly as you unroll it so that it lies flat but do not squash it so that it becomes compressed.
4. When you reach the other side of the loft cut the blanket with scissors, again taking care not to block where the necessary ventilation comes in under the eaves.
5. Continue to lay the insulation between the other joists.

6. When joining two rolls, make a butt join, pressing the ends close to each other.
7. Cut the insulation so that it fits tight around pipes.
8. Try to place insulation under loose electric cables so that there is no danger of them becoming overheated. Where practicable, fix cables to the sides of the joists to keep them out of the way.
9. Never insulate under the cold water cistern. Leave a gap in the insulation so that warm air from below will keep the chill off the base of the cistern and help to prevent the water from freezing.

INSULATING WITH LOOSE-FILL

It is easy to insulate with loose-fill granules, you pour the material between the joists and level it out. Make a simple levelling gauge so that the granules are at an even depth. Decide how deep the insulation layer is to be as it must be at least 4in (lOOmm)-and deduct this measurement from the depth of the joists.
Cut a piece of hardboard, chip-board or wood to a wide T-shape which will fit the gap above the loose-fill. The 'arms' should rest on top of the joists, so that when you run the gauge between two joists the granules are spread to a consistent depth.

Other DIY Topics	Related Info
Insulating a Loft Insulating a Roof Lagging a Loft Hatch Door	Condensation Problems