Hi all,

Thanks for all the advice given in here, so helpful 

I was looking at some doors with twin fin intumescent strips fitted to the frame, but when the strips were fitted they have joined two pieces together as it looks like they did not buy the correct lenghts for the frame, i was under the the impression that they need to be fitted in one continuous lenght unless passing ironmongery, due to smoke leakage.

should these be replaced with one continous strip from top to bottom?

once again thanks

Mr B

Ideally yes

https://www.ifsa.org.uk/documents/  is the place to look for fact sheets, information and guidance about intumescent seals and smoke seals.