Mastic is used as covering layer for mineral wool transits in installation penetrations combined with bst Fire Stop Boards and bst Fire Stop Coating “Type A“, and also as a fire-resistant filling for seams

The Fire Stop Mastic is a paste compound to be applied undiluted by hand (with trowel or spatula

Elastic, halogen-free fire protection compound with heat-expanding (intumescent) effect. In case of fire material expands up to tenfold of its volume and thus forms a heat-insulating layer

Disposable containers of 5 kg, 15 kg and 35 kg, or re-usable containers of 60kgs. If requested, material can also be supplied in cartridges of 310 ml

When installing a mineral wool transit, the bst Fire Stop Boards are used as carrier material (density 140 kg/m²). Depending on application and fire resistance class one or two boards are to be used for one penetration. Boards are either coated on one or both sides with Type “A“. To complete the mineral wool transit only a covering layer of Type “K“ is necessary