flat roofs waterproof insulations 66 roof covering 34 thermal insulation 30 insulation materials 26 protection of buildings 21 insulation works 18 more ... repairs 17 building designing 15 green roofs 14 imperfections 12 asphalt 11 reconstruction 10 drainage 9 roofs 9 building dampness 9 construction materials 8 material jointing 7 multilayer design 7 photovoltaic cells 5 foil 5 fire protection 5 sloping roofs 5 construction works 5 history 4 climate 4 windows 4 roofing 4 weather effects 4 rebuildings 4 less ...