Using loose fill as your insulating material is a viable alternative to other types, such as fibreglass rolls, and is very easy to lay down, or fit, into your loft.
It is a much cleaner and more convenient product to use and, in material such as vermiculite, is a completely natural and environmentally friendly product.
Whereas traditional material such as a fibreglass blanket is supplied in rolls this material comes in bags or sacks which are simply emptied and raked into the gaps between the joists and the ceiling / loft floor.
Laying The Insulation
Although the material is simply poured between the joists in the roof space there are a few important points to note.
The first is pretty obvious – make sure there are no cracks or holes in the ceiling!
The last thing you want is someone in the bedroom below being showered by a cloud of insulation falling through cracks in the ceiling. Needless to say, any cracks should be patched before the insulation is put down.
In a similar vain it the gaps between the ends of the joists under the eaves must be sealed. Simply screwing a piece of plywood between each pair of joists (take care to leave a gap behind the board for ventilation) should be more that sufficient.
Before laying the material make sure that the space between the joists is relatively dust-free and that the depth of the joists will be sufficient to hold the amount of loose fill insulation necessary to give an acceptable level of insulation.
As most joists have a depth of four inches or so it will be necessary to raise the height of the joists by adding wooden strips along its length.
It is important that any electrical cables are kept above the insulation so they may need to be re-routed by an electrician.
Actually laying the material is simplicity itself. Simply pour out of the bag and brush or rake between the joists ensuring the fill is kept consistently level.
For the loft hatch it is best to use blanket material contained either by plastic or an old sheet.
If you are simply insulating the loft and not putting any boarding over the loose fill insulation, make sure you keep a check on the level of the material during the winter months as high winds can unsettle the material and blow it around the roof space.
For more info see the related pages below
Structural calculations for loft conversions are of course hugely important to ensure safety and that the proposed plans meet building regulations
What is the difference between planning permission and building regulations approval for loft conversions ?
Using And Fitting Loose Fill Insulation In Your Loft