grubby loft floor insulation

[colinpost]

Before i start considering work on the new structural loft floor, should i remove the grubby 1970s floor fiberglass insulation ?

Dirt and dust has collected because the roof (to be replaced etc) has no felt layer. I suspect the insulation properties of the fibre glass has deteriated, due to dirt and compacting ?

 

[freddiemercurystwin]

It won't have lost much value in terms of heat loss. Prey tell what structural work are you about to do that necessitates the removal of the old insulation.

 

[mointainwalker]

If the weight of dirt has substantially compacted it, that will reduce the insulation value.

If you feel it is worth while shak ing it out and seeing if you can get it near the original thickness, have a go.

If you decide to replace it, you could still overlay two thicknesses of the existing to improve the effect. this will save you cash in buying as well as the need to drag this grubby mess through the house.