Insulation

[Tslidder]

I have a Ideal slider and Glasco slider that I will start on restoration soon I hope.In the past I restored a Vendo 63 square top and when installing the bats of insulation I inserted them in plastic bags like the one's you get from the dry cleaner over your shirts. and sealed them. All seems good many years past. I have been reading the restoration guys and they all seem to just lay the insulation in and I think it's not backed.I think that's what home insulation would refer to as a vapor barrier.Any info would be appreciated.