Fire door sets never fit openings

[Chris562]

I was thinking of getting into fire door installation work. Did a good course covering the topic of installation.

However I’ve since learned from a friend who is in the business of installation work that you really need a workshop to adapt the doors and frames as they will never fit existing openings when doing replacement work.

I found this to be a real let down as I naively thought I could be mobile fitting door sets on the road.

Any feedback/advice greatly appreciated, thanks.

 

[Neil Ashdown MAFDI]

If you carry out a full on-site survey for each door before you purchase the door-sets and order them accordingly, you should be OK. 

[Mike North]

There should be minimal adjustment to the leaf or frame if the door is correctly measured.  The frame should be fixed and seal to the opening giving a door to frame gap of 2 to 4 mm.  As Neil says if the surveyor dose a decent job there should little adjustment,  unless you are installing door blanks

[Chris562]

What has been relayed to me is that the openings are rarely a standardised size so the door sets won’t match. I’m referring to older properties where I suspect most of the work will be done.

Surveying work isn’t the issue, it’s more you won’t find off the shelf door sets to fit the openings and so altering frames and doors is nearly always necessary.

That would mean having some kind of workshop to carry out alterations which I was hoping to avoid.

[Mike North]

That's why you survey, measure the door and then order the correct size

[Chris562]

Ok so the manufacturers make doors and frames that are standardised sizes, the openings aren’t. Who creates the bespoke size door assembly to fit the opening you have surveyed?

[Neil Ashdown MAFDI]

As Mike says, that's the whole point of the survey.  So that you can order the correct sized door and if you can't get what you need 'off the shelf' you can get them custom made. 

Clearly, if you did have a workshop you could fabricate the doors using certificated fire door blanks.  But you need will also need the knowledge to do it correctly to retain that certification. 

[Chris562]

So how common is it to be able to get ‘off the shelf’ door sets without the need for modification?

[Neil Ashdown MAFDI]

If you go for an 'off the shelf' fire door leaf, be aware that trim allowances are often very tight.  It may be necessary to use thicker door frames to comply with fire door leaf  installation instructions, where the surrounding wall to door frame gap would otherwise be too large.  So my guess would be no better than 50 / 50, depending on the type of property, and I would be ready to expect to have to order custom made doors or fabricate them from door blanks.  However, there are some 'off the shelf' fire doors (Premdor CF625 solid GDC chipboard for example) that permit significant trimming off the bottom edge.

[Mike North]

From what I have found in my experience, even with modular builds, off the shelf doorsets seldom fit without modification.  That’s why we measure every door that fails before ordering the new door.  It works out cheaper in the long run.

[Chris562]

5 hours ago, Mike North said:

From what I have found in my experience, even with modular builds, off the shelf doorsets seldom fit without modification.  That’s why we measure every door that fails before ordering the new door.  It works out cheaper in the long run.

So you get the door made to fit. I assumed the main suppliers/manufacturers would only supply standard sizes and any modifications needed would have to be done by the fitter.  So do the major suppliers custom make the doors for you? Also I imagine lead times are a few weeks for getting the doors.

[Mike North]

To ensure that the door fits, each door is measured.  Lead times are currently running at 8 to 12 weeks for a fully certified door.  Generally, the have a range of standard door sizes, but you still have to measure the opening to find out which standard door will fit.

We have several options whilst waiting for a delivery, enhance repair the door, replace with a blank door, close the bedroom, close the flat, close the building or keep a waking watch.