Question about 'rearranging' loft insulation...

scottishnellie

Hi - does anyone know anything about loft insulation?!

When we bought this house the previous owners had paid a company to insulate the loft which is not floored. Instead of laying the insulation between the joists, the company has used wider rolls and laid them right across all the joists. We now want to floor the loft ourselves using the boards you can get in B&Q. But as we can't nail them on top of this I want to know whether its ok to roll it up and then re-lay it by stuffing it down between the joists instead. As its thicker than needed it would mean packing it down.

Is this advisable?!

andrew-b

This seems to be quite a common problem these days. To work at it's optimum the insulation shouldn't be packed down as else you'll exclude most of the air within it that acts as an insulator.

I think the recommended thickness of loft insulation is currently 270mm (See http://www.energysavingtrust.org.uk/home_improvements/home_insulation_glazing/loft_insulation) which is usually 170mm higher than the level of the joists. You should find insulation is already between the joists as well as the layer going across the joints - that's the usual way it's done anyway.

The best way of flooring the loft whilst maintaining the best levels of insulation is either to extend the height of the joists - maybe running some timbers across the existing joists or to use a purpose made insulation board with a floor layer built in - Knauf insulation make them if i remember rightly.

Can you not get by with just a small area boarded out for storage near the loft hatch and either sacrifice some of the insulation in that area or raise it up above the insulation.

Oh and lastly, use screws rather than nails else when you come down from the loft you may find cracks at the joints of the plasterboard in the ceilings.

Hope that helps

Andy

woodbutcher_2

You can use space blanket type insulation which gives the same thermal value for a thinner product.Not cheap mind you.They had a BOGOF deal on it last time i was in B and Poo.

scottishnellie

Thanks for your replies- very helpful. :beer: