We are about to insulate our suspended floors and we have a small problem, we have more joists than air to insulate as the joists are doubled and they only have about 300mm between them. This means that we will have loads of thermal bridging which I intend to mitigate by insulating under the floors with 70mm insulation. As there is only 240mm from the underside of the joists to the soil level I need to fix the underfloor insulation from above. The technique I intend to use is to use it so create