Carpentry & Joinery

Want to fit firedoors in non-standard frames... and carpenters/shops saying it can't be done

Anonymous user 23/02/2024 - 2.52 PM

Hi, I am replacing some of the interior doors in my house. Current door measurements are: 2 at 71cm x 190cm 2 at 76cm x 197cm All the door frames are a bit wonky, and bulging, so that even the two that are almost a standard size are not quite so, with some areas where the frame is over 77.5cm wide. We will be raising the floor level by ~2.5cm (plywood, underlay, and thick carpet) and so the height of the 197cm frames will be 'reduced' to ~194.5cm. The main reason we are replacing the doors is to get heavy doors to reduce sound transmission, and also so that when we do the loft conversion, we will already have fire doors along the escape route. As such, we want heavy doors, and preferably fire doors. But almost all shops say that their doors can only be reduced by a couple of mm, unless they are solid pine doors. We have been advised not to alter the two short door frames so they are taller, on the grounds that it will A) be very distructive, and B) ruin the line of sight effect whereby all the doors on the landing look the same height. Can anyone please advise me on what I should do? Will cutting 8cm height off a fire door actually make any difference to the structure of a door? Should I replace the wonky frames so they are straight, or is there a better way to deal with it? Or should we just replace all the frames, and accept that it will be destructive? Also, for fire-doors, does it really matter what the frame is made of? Your help is greatly appreciated... I've heard so many conflicting opinions, and would really appreciate sound advise from someone not looking to get my money.