One of our client requires firestop to seal joints between curtain wall and concrete slab. CFS-SP WB is usually the best product for this application, but the joint width as communicated by the client is 15 inches and the product UL certificate is for joint widths up to 8 inches.
Another product I came across is CP 674 V, but I am not sure that it would be applicable for this application. I need your suggestion that may I suggest CP 674V for this application secondly, I want to understand that as per the data sheet we have to leave a 25 mm gap, why do we leave this gap when the objective is to seal the joint.
Dear Mr. Hadi,
Thank you for your question.
Since, there is no joint detail, I can't exactly say which solution in fire stopping can apply here. But if the detail is like the one in the screen shot, then CP 674 is the correct one. The gap of 25mm is required for ventilation purpose because this is exterior of building and moisture starts to develop on the insulation layer if we completely close this gap.
CP674 has an intumescent coating on the end, which will expand and close this 25mm gap in the event of a fire. Max width of CP 674 available is 400mm.
Hope that's the answer of your question.
Regards
Muhammad Usman