ELG Paul

Hi we have recently been replacing existing fire doors to meet regs. We have been keeping to the 3mm gaps however, the doors are not self closing as a result of the smoke strips. The strips we use are from Howdens - does anyone else have the same issue? Perhaps there is another supplier out there that have softer bristles We also noticed that a previous contractor had cut the strips in deeper to overcome this issue but we feel this is not the solution as it was clear the router bit used was not the ones specifically designed for intumescent strips not to mention how far away the intumescent was from the frame.