Gaps between Botton of jambs and F.F.L remedial?

[Guest Jay]

Hi,

I have a door set that has an 8mm gap at the bottom of jambs to FFL. Whats the recommended remedial works that can be done?

[Neil Ashdown MAFDI]

Assuming the door frame jambs are timber.   Then insert solid timber pieces, of the same type as existing, using urea formaldehyde based adhesive to tightly plug the gaps completely with no voids.