Dont compress loft insulation works by trapping air so it must not be compressed yet the recommended depth of insulation is 270mm energy savings trust loft storage needs to be supported on flooring boards raised above the insulation loft lifters attach to roof joiststrusses elevating floor boards creating required space for insulation to perform as expected adjust for stability fully adjustable each leg is made of two parts one threaded into the other allowing a twist in either direction