Knauf Earthwool ceiling insulation comes in different widths and thicknesses to suit the common joist height and spacing. Knauf Earthwool ceiling insulation batts come in a compressed pack for easy transport. R6.0 Earthwool Ceiling Insulation Batts are an excellent choice for DIY homeowners who want to save money on power bills. About 30% of the heat in your home escapes through the roof, but this percentage can be lessened with the correct insulation, thus keeping your home warmer in the winter and cooler in the summer.