Hi everyone,my appologies if this has been covered elsewhere. I have a lot of nominal fire doors with gaps around them more than 4mm meaning i can't get a cold smoke seal with my intumescent brush strips. The doors are a flush veneer faced door with a chipboard core.i was wondering if anybody knew if i would be ok to re edge them with hardwood lipping or if it is a no no due to the core of the door? I m sure it isn't a problem re edging solid timber core doors

Thanks

It is permissible to fit hardwood lippings to timber-fire resisting doors.  Make sure the lipping is the correct type of hardwood, to the correct minimum and maximum dimensions and use the correct adhesive to suit the type of door core.

Obviously, don't add a new lipping on to an existing lipping!

Firstly youll need to remove the existing lipping, easiest way is electric plane, get lipping cut over size of depth, and then glue to edge of  door, use nails to  hold it in place while it drys, leave nail heads proud so they can be removed.

Problems i had in the past where ensuring the planed surface was flat and smooth, also gluing lippings to a chipboard core is difficult to get a strong bond,  fit door back into frame and push it againt door jamb and mark on the lipping  where it touches the frame now plane to that line and then a bit more for the brush seal to seat in and stand proud.

It may be easier to line the hinge side of frame with a thin lippping and then refit hinges , and add on a new side bead on the hinge side or to make it symmetrical both sides .