When fitting a 30 minute fire door set into a structural opening how much of a gap can you have between the door frame and the structural opening without compromising the fire integrity.

We normally allow a max of 10mm gap – meaning that this would be 5mm on each side of the door.

If you require a more in depth information check out Architectural and Specialists Door Manufacturers Association and download the Best Practice Guide to Timber Fire Doors and there is one on installation. Also "BS 8214:2008 Code of practice for fire door assemblies" is relevant. Try http://www.firesafe.org.uk/fire-doors/

Hi,

Just wondering what the gap between the bottom of the FD30 fire door and the floor jam has to be?

Joiner in just now. Is it between 3-5mm [seems quite large gap?

When fitting a new 60min fire door set what is the maximum gap. We have been pulling out old frame and we are finding the new frames have a gap of 35mm down each side, is this to big for fire foam 

Yes 35mm is too big a gap.  If using fire foam make sure it complies with the requirements of BS 8214: 2016 Timber-based fire door assemblies - Code of practice.  The gap requirement depends on the materials you are using to fill the gap, BS 8214 guidance based on using mineral fibre tightly packed and capped with intumescent acrylic mastic on both sides states 20mm as the maximum gap but refer to the Standard so that you can demonstrate compliance.