How to alter frame to take 44mm door

[Steve Blackdog]

Following a fire risk assessment, I need to replace some doors with FD30 fire rated doors. No need for intumescent strips etc, just heavier doors.

One is easy - the frame is around 20 years old and the door jamb can easily be adjusted. The other door frame is an old 19th century solid lump. The old door is thin and the rebate needs to be enlarged to take a thicker door.

My first thought was to use a router. But it would be very awkward and might look a mess.

Is a rebate plane the answer, tidied up with chisels where the plane won’t reach?

Thanks in advance.

 

[johnnyb]

I wouldn't but I did post a thread on how I achieved something similar. A rebate plane is not the best tool maybe suited to the final clean up.
Tbh 35mm fire doors are available. My post was enlarging 25mm rebates for batten doors to 36mm for normal doors. But it's a lot better to just use 35mm fire doors

 

[johnnyb]

https://www.ukworkshop.co.uk/threads/more-door-stuff.143982/post-1680380

 

[ChaiLatte]

Do you have a tracksaw?

Fix a piece of plywood on the part where the door would be, wide enough to accommodate the track. Clamp the track to the plywood and run the saw along the track. That will give you a nice line along 80+% of the height.

If you have something that would allow your router to work with the guide rail, that would get you even closer to the top and bottom.

WIth either of the above, the cutting tool is well held to the guide rail.

Even without a track, a second piece of plywood screwed to the first would give a straight edge along which the router could run. A shorter version could be used for the top horizontal section. This "guided but freehand" option does require you to hold the router securely against the straight edge.

 

[Steve Blackdog]

7

Do you have a tracksaw?

Fix a piece of plywood on the part where the door would be, wide enough to accommodate the track. Clamp the track to the plywood and run the saw along the track. That will give you a nice line along 80+% of the height.

If you have something that would allow your router to work with the guide rail, that would get you even closer to the top and bottom.

WIth either of the above, the cutting tool is well held to the guide rail.

Even without a track, a second piece of plywood screwed to the first would give a straight edge along which the router could run. A shorter version could be used for the top horizontal section. This "guided but freehand" option does require you to hold the router securely against the straight edge.

that’s not a bad idea.

 

[Steve Blackdog]

https://www.ukworkshop.co.uk/threads/more-door-stuff.143982/post-1680380

thanks for the link. I had tried a few different searches. Didn’t think of “more door stuff”

I think I should try your solution.

 

[johnnyb]

Someone else tried it successfully.

 

[hlvd]

Old school would be chisel to chop down to the line like you would for a butt hinge, then rebate or shoulder plane to clean it up and split the line. Corners and the bottom 4” are difficult and need to be done mostly with a chisel and bullnose.

A router might work if you’ve enough width to tack a straight edge onto the frame/casing as using the fence will be difficult as it’ll want to skate off the architrave if it’s profiled. Corners and the bottom 4” will still need doing by hand,

A multi tool might also work, especially coming in along the hinge rebate outside in.

Whatever way you choose won’t look great as it’s really difficult getting it to look tidy, good luck.

 

[HOJ]

Following a fire risk assessment, I need to replace some doors with FD30 fire rated doors. No need for intumescent strips etc, just heavier doors.

Curious as to why, having done an FRA, there is no requirement to provide any seals, does that not somewhat defeat the objective/compromise the effectiveness of a fire door.

 

[ChaiLatte]

Corners and the bottom 4” will still need doing by hand,

If the router only reaches to within 4" of the bottom, that implies that the machine is more than 8" diameter.

My trim router has a base 88mm in diameter so with a 6mm cutter in it would reach to 41mm from the corner, quite a lot closer than 4". You can also buy an offset base for a trim router that gets you (at a guess) to within 30mm.

 

[johnnyb]

The issue I found was only a 1/2 inch router is man enough with cheap 1/2 inch cutters. Also beware of nails. I must have hit a dozen. My technique was to cut them and pull them out. Freud worktop cutters were much less chippy than cheap brands.

 

[Woodworker Ireland]

As a Carpenter i wouldnt touch it unless removed old frame and fitted a new one. Ive worked in England with those narrow doors dont know why ye still use them. 44mm doors are standard here in Ireland. Still think you would need instumesent fire strips to get the rating.

 

[Steve Blackdog]

To be honest, the whole assessment was very confusing. No explanation or advice- just a list of fairly arbitrary recommendations. One of his alternatives was to disconnect the cooker. We’re not talking about a large multiple occupation building. This is a two bed cottage.

 

[Rupesh]

I've done a perfectly serviceable job with a 1/2 inch router, chisel & rebate plane

 

[pip1954]

It maybe a strange idea could you plant so timber on top to make up the extra thickness instead of making rebate deeper .
Pip

 

[Agent_zed]

To be honest, the whole assessment was very confusing. No explanation or advice- just a list of fairly arbitrary recommendations. One of his alternatives was to disconnect the cooker. We’re not talking about a large multiple occupation building. This is a two bed cottage.

Hang on why do they need replacing? Is this some commercial use building or something? Is there another option available like linked firealarms in each room?

 

[Steve Blackdog]

It is a short term letting property. The rules say you need a fire risk assessment. We’ve installed linked smoke and heat alarms and a mister/sprinkler system. We thought it would be prudent to get a professional fire risk assessment, rather than just do one ourselves.

Having had the risk assessment we are potentially at risk if we just ignore it. TBH, it has been more trouble than it’s worth. I’m half inclined to forget the fire doors. It’s almost inconceivable that someone would be able to ignore the alarms - they make a right racket!

 

[Agent_zed]

It is a short term letting property. The rules say you need a fire risk assessment. We’ve installed linked smoke and heat alarms and a mister/sprinkler system. We thought it would be prudent to get a professional fire risk assessment, rather than just do one ourselves.

Having had the risk assessment we are potentially at risk if we just ignore it. TBH, it has been more trouble than it’s worth. I’m half inclined to forget the fire doors. It’s almost inconceivable that someone would be able to ignore the alarms - they make a right racket!

This doesn't appear to say you need a risk assessment https://www.gov.uk/private-renting/your-landlords-safety-responsibilities or is there something else that I should be looking at?

I am aware if it is multi occupancy or has 3 floors that you need firedoors on a fire route/exit, but for a normal 2 story building my understanding of the rules are as per the .gov page above.

I'm not necessarily saying you should ignore the assessment but they are always going to be covering their backs.

My parents house has ducted air heating so has vents above the doors, so the building inspector said don't bother with firedoors as it is pointless.

 

[taco chewy]

It maybe a strange idea could you plant so timber on top to make up the extra thickness instead of making rebate deeper .
Pip

I'm planning on doing something like this. Adding a 9mm baton all around the inside of the frame so a 44mm door can fit in a 35mm rebate frame in an old building.
Has anyone got experience of doing this successfully? I think the hinge screws and lock would still go into the original part of the frame so no compromise on strength of fixings.