A fire door closer looks like a fairly simple bit of ironmongery.
You screw the closer to the door, fit the arm, fix the other end to the frame and adjust it until the door closes.
In reality, there is quite a lot more to getting a closer right.
Over the years I’ve seen closers fitted almost every way you can imagine. I’ve seen them upside down, back to front, with the arms fitted the wrong way, sitting too high, in the wrong position and even one fitted slap bang in the middle of the door.
Somehow, they have still managed to make some of them work.
I have to congratulate them on being so creative. 🤣
But getting a closer to work is not the same as installing it correctly.
The closer, arm, frame, hinges, seals, latch and door all have to work together.
This is how I approach fitting them.
Before You Start Fitting the Closer
Before drilling any holes, I look at the door and the surrounding area.
There are a few things I want to know first.
Check for Wall and Recess Clearance
One problem I see is closers being fitted without checking what happens when the door is actually opened.
If the door opens close to a wall, into a recess or beside a return wall, the closer body or arm can sometimes hit or snag the wall as the door opens.
It might look perfectly fine with the door closed.
Open the door and watch what happens.
The closer and arm move as the door opens, and you need to make sure there is enough clearance throughout the complete movement.
This is something you want to find out before you drill the first hole.
Depending on the particular closer, there may be more than one permitted fitting arrangement. If so, the available space can help determine which arrangement is suitable.
Always check the manufacturer’s instructions and the fire-door assembly evidence before choosing the arrangement.
Think About How It Will Look
There is another thing I think people sometimes forget.
What is this going to look like when it’s finished?
A closer can work perfectly well and still look untidy.
This is particularly noticeable on doors in corridors where the closer body and arm can be very prominent.
Where the permitted installation arrangements allow a choice, I prefer to think about putting the closer on the narrower or less visually prominent side.
Look at:
- which side the closer will be seen from
- how far the arm projects
- nearby walls
- recesses
- ceiling height
- architrave
- the finished appearance of the corridor.
Obviously, appearance doesn’t override the required fire-door installation arrangement.
But if you have two permitted ways of doing something, I don’t see why you shouldn’t think about how it will look.
🛠️ Professional Tip: Don’t just ask “Will it work?” Ask “What is it going to look like when I’m finished?”
A fire door is still a finished piece of joinery.
Choosing the Correct Closer
You need to make sure the closer is suitable for the door and the particular fire-door assembly.
Controlled door closers are covered by BS EN 1154, which includes power sizes from EN 1 through to EN 7.
The following is a useful reference to the EN 1154 power-size classification:
| Power Size | Maximum Recommended Test Leaf Width | Test Door Mass |
|---|---|---|
| EN 1 | 750 mm | 20 kg |
| EN 2 | 850 mm | 40 kg |
| EN 3 | 950 mm | 60 kg |
| EN 4 | 1100 mm | 80 kg |
| EN 5 | 1250 mm | 100 kg |
| EN 6 | 1400 mm | 120 kg |
| EN 7 | 1600 mm | 160 kg |
These figures are a reference to the EN 1154 power-size classification, not a simple rule saying that a particular door weight automatically means you need a particular closer.
The actual selection can also be affected by:
- door width
- door mass
- door height
- mounting arrangement
- seals
- latch resistance
- air pressure
- draughts
- wind conditions
- frequency of use
- the particular closer
- the fire-door manufacturer’s certification.
The closer must also be suitable for the particular fire-door assembly.
Don’t just look at the door weight and pick a closer from a table.
Check the closer manufacturer’s information and the door manufacturer’s supporting evidence.
Use the Manufacturer’s Template
If the closer comes with a template, use it.
The template gives you the manufacturer’s intended positions for the closer body and arm arrangement.
I’ve fitted enough closers over the years to have my own quick ways of doing things, but the template is still the starting point.
Once you’ve correctly installed the first one, you can develop a repeatable method for fitting the same closer again.
The aim is to reproduce the correct geometry quickly and consistently.
🛠️ Professional Tip: Treat the manufacturer’s template as the starting point, not an inconvenience. Get the first one right and the next ones become much quicker.
Fitting the Closer Body
Once I’ve established where the closer needs to go, I offer it up to the door.
When I put the first screw into the door, I don’t spend ages measuring to get it perfectly level.
I eye up the top line of the closer with the top of the door.
It’s quick and, with experience, you can get it level very accurately by eye.
The first screw holds the closer in position.
If I need to, I’ll take the other screws and lightly tap them into the other fixing positions to locate the holes.
I then remove them, pre-drill as required and fit the remaining fixings.
The exact screw type and pilot-hole size should follow the closer manufacturer’s requirements and the material being fixed into.
How Quickly Can You Fit a Fire Door Closer?
Once I’ve got a particular closer I’m familiar with, I don’t treat every door as a completely new job.
I normally do my closers in one go.
Once I’ve got the first one set up correctly, I can get into a rhythm and work through them without rushing.
Using my method, I can comfortably fit around six closers in an hour on straightforward, prepared doors.
That’s roughly 10 minutes per closer.
I’ve also taught this method to numerous joiners over the years, and several of them still use the same method today. So it’s not something I’ve developed just to work quickly for myself — it’s a repeatable way of fitting them that other experienced joiners have adopted as well.
Now, that doesn’t mean every fire door closer should take ten minutes.
There are obviously doors where you have to stop and deal with something else — awkward access, damaged frames, difficult fixings, different closer arrangements, old hardware that needs removing, or a door that isn’t operating correctly in the first place.
And I’m not talking about racing against the clock.
The reason I can work at that speed is because I’ve already established the method.
I know where the closer body needs to go, I use my datum point, I get the body level, mark the remaining holes, fit the arm and then move on to the next door.
It’s the repeatability that saves the time, not rushing the job.
For comparison, online trade guidance gives a much wider range for straightforward closer installation, commonly anything from around 30–60 minutes up to 1–2 hours depending on the door, closer and preparation required.
🟧 Professional Tip
Don’t try to become faster by rushing. Become faster by removing unnecessary steps.
Once you know exactly where everything goes and use the same sequence every time, the speed comes naturally.
Make Sure the Closer Is Level
I always check the level between the closer and the bar/arm arrangement that locates into the frame.
You don’t want the closer sitting noticeably out of level and then expect the arm to operate correctly.
The body, arm and frame fixing need to work together as the manufacturer intended.
Fitting the Arm – Standard Arrangement
For the most common fitting position, I fit the arm straight initially.
Once the arm is fitted to the closer, I then pull/rotate it around into its working position.
This creates the required preload.
The important point is that the arm isn’t just fitted wherever it happens to sit.
The preload is part of getting the closer correctly set up.
When the arm is correctly tensioned and in its finished working position, the part of the arm that fixes to the frame ends up projecting at approximately 90° to the relevant door/frame arrangement.
The section of the arm coming back towards the closer is then at an angle.
That is the finished geometry.
Don’t confuse this with the starting position. The arm can start straight and finish at a completely different angle once it has been tensioned.
The Thumb Trick
When I’m positioning the frame end of the arm, I use my thumb as a visual gauge.
It’s a quick way of getting a consistent position without repeatedly measuring every part of the arm.
I offer the arm up to the frame and use my thumb to judge the correct spacing and position.
Once I’m happy, I use a sharp point to mark the fixing-hole positions on the frame.
I prefer this because I’m marking the actual position of the arm rather than trying to calculate where it should be.
Marking and Predrilling the Frame
The sequence I use is:
Offer the arm up → use the thumb gauge → mark with a sharp point → pre-drill → fix.
For timber frames I normally use around a 3–4 mm drill bit, depending on the size of screw and the timber I’m fixing into.
Hardwood in particular needs proper pilot holes.
It makes starting the screws much easier and reduces the chance of splitting the timber or damaging the fixing.
Underslung / Parallel-Arm Closers
Underslung closers are different.
You don’t simply use exactly the same starting position as the standard arrangement.
With an underslung closer, the arm is normally positioned so that when the closer is being screwed onto the door, it is already pre-stressed by approximately one notch, depending on the particular closer.
This means the closer is already under pressure.
It wants to pull away from the door while you’re trying to screw it on.
That can make fixing the closer noticeably harder.
You need to hold it properly against the door while getting the fixings in.
When the arm is then attached sideways and brought into its working position, it goes from:
pressing against the door under pressure
to:
parallel with the door and in line with the closer body.
That is the finished position you’re looking for.
The exact arrangement can vary between manufacturers, so always check the particular template and instructions.
Preload Matters
Preload is one of the parts of closer installation that is easily misunderstood.
The closer needs to have the correct spring tension and arm geometry to provide the required closing force through the closing cycle.
Too little preload can leave the closer struggling during the final part of closing.
Too much can make the door unnecessarily difficult to open and can put additional loads into the mechanism and arm.
The aim is to get the preload correct for that particular closer and installation arrangement, rather than simply putting as much tension into it as possible.
Fixing and Tensioning the Arm
The arm itself sometimes needs to be screwed together or tensioned during fitting.
These fixings need to be properly secured.
Some arms have multiple fixing locations, so make sure you’re using the correct position for the particular installation arrangement.
Some arms also need winding out as part of the assembly.
Don’t assume every closer arm works exactly the same way.
A Stubby Screwdriver Will Save You
Some of the arm fixing screws can be a nightmare in a room with a low ceiling.
There simply isn’t enough room to get a normal screwdriver into a good position.
I’ve seen these screws get chewed up because people are trying to tighten them at an awkward angle.
My advice is simple:
Put a stubby screwdriver in your closer-fitting tool kit.
You will thank me for it.
😂
It gives you the access you need when the ceiling or surrounding construction is in the way.
Make Sure the Arm Is Properly Secured
Another mistake I see quite regularly is the arm not being screwed up properly to the closer.
It might look fitted, but the fixing can work loose during use.
I’ve also seen arms sitting too high and then snagging as the door operates.
Don’t just look at the arm when the door is closed.
Open and close the door and watch the arm move.
Check:
- the fixing is secure
- the arm is at the correct height
- the arm isn’t lifting
- the arm isn’t dropping
- the joints aren’t binding
- the arm isn’t hitting the frame
- the arm isn’t hitting the wall
- the arm isn’t catching the closer body.
The complete arm needs to operate freely through its intended movement.
The Door Must Be Free Throughout Its Movement
This is one of the biggest checks I make.
The door should not snag or bind anywhere.
Not when opening.
Not when closing.
And not at any point in between.
Check the complete movement.
The door needs to be free from:
- hinge binding
- frame contact
- floor contact
- latch interference
- excessive seal resistance
- arm interference
- other mechanical obstructions.
If the door is fighting against something, the closer is being asked to compensate for a problem somewhere else.
A closer should not be used to hide a bad installation.
New Fire Door Seals Can Be Very Stiff
One thing I’ve found over the years is that a newly fitted fire door can sometimes be blamed on the closer when the real problem is the new seals.
Some new smoke and brush seals can create quite a lot of resistance.
I’ve also found that some manufacturers make their brush seals more flexible than others.
You can have two products that look like they are doing the same job but behave very differently when the door is closing.
New seals can settle with use.
Sometimes they settle quite quickly.
Sometimes it can take a few weeks.
As they bed into their working position, the resistance can reduce and the door can become much easier for the closer to operate.
But you cannot simply leave a fire door unable to close and say:
“The seals will settle.”
The finished door still needs to close properly.
The government fire-door guidance specifically uses a test from approximately 15° and requires the door to close fully into the frame.
Sometimes You Have to Increase the Closer
There are occasions where you are left with little practical option other than increasing the closer power or closing speed enough to make the door close and latch reliably.
If this is because of new seal resistance, I don’t consider that the end of the job.
I would get the door closing reliably and book a return visit shortly afterwards.
Once the seals have settled, check the door again.
If the extra closer adjustment is no longer required, bring it back to the appropriate setting.
One thing I always do if I’ve changed the closer from its original setting is mark the original position first.
I use a sharpie to put a small mark against the adjustment screw and the closer body, showing exactly where the original setting was.
That way, if I’ve temporarily increased the closer to overcome stiff new seals, I know exactly where the factory setting was.
Once the seals have settled in and the door is closing properly, I can quickly return the adjustment to its original position rather than trying to remember where it was.
It’s a simple little trick, but it can save a lot of messing about later.
🛠️ Professional Tip: If you’ve had to increase a closer because of new seals, make a note to come back and check it. Don’t leave a closer permanently overpowered because the seals were stiff on day one.
Don’t Assume Every Brush Seal Is the Same
This is another area where experience comes into it.
I’ve found that some manufacturers’ brush seals are noticeably more flexible than others.
If you’re regularly fitting the same type of door, you soon learn which approved seal products make the closer’s job easier.
Obviously, you can’t simply fit whichever seal you prefer.
The seal still has to be compatible with the particular fire-door assembly and its supporting evidence.
But where there is a permitted choice, it is worth understanding how the different products behave.
A very stiff seal can make a perfectly good closer look underpowered.
Check the Closer Arm Against the Frame
Once the arm is in its correct position, offer the frame end up to the frame.
Use the actual arm to establish the position.
Use the sharp point to mark the holes.
Predrill the fixing holes as required.
Then fix the arm securely.
I always check the arm again after fixing it.
It is very easy to have it looking right while stationary but sitting slightly too high or in the wrong position once everything is tightened.
Closer Arms and Architrave
This is something I’ve been looking at more closely recently while researching fire-door testing and certification for another product.
I was traditionally taught to fix the closer arm through the architrave at the fixing point.
However, I’ve since discussed fire-door testing directly with Certifire and was told that a relatively small proportion of fire-door tests are carried out with architrave fitted as part of the tested arrangement.
That raises an important practical point.
Don’t automatically assume the architrave forms part of the closer-arm fixing structure.
The actual fire-door evidence and the closer manufacturer’s installation instructions need to establish where the arm or bracket is intended to be fixed.
Where the required arrangement is for the arm/bracket to be fixed directly into the frame, don’t simply rely on the architrave as the fixing material.
I’m not putting a specific percentage on the Certifire information here because I don’t have that figure published in a document.
The important point is:
Check the evidence rather than assuming the architrave forms part of the fixing arrangement.
Double Fire Doors
Double fire doors need another level of checking.
Don’t just fit a closer to each leaf, test them individually and assume the pair will work.
The two leaves need to close in the correct sequence where the doorset configuration requires it.
For a typical pair where one leaf has to close first:
Inactive/slave leaf → active/master leaf
The inactive leaf closes first and the active leaf follows.
Where a door selector or coordinator is required, it needs to be correctly fitted and operational.
The exact arrangement depends on the doorset and hardware configuration.
Always test the doors together.
Open both leaves.
Release them.
Watch the complete closing sequence.
Repeat the test from different opening positions.
Make sure the meeting stiles don’t fight each other and that both leaves close and latch correctly.
Testing the Closer From 90°
This is how I was taught to test a closer.
Open the door to approximately 90° and release it.
My practical benchmark is around:
5–8 seconds
from opening to closing.
This is my practical trade benchmark rather than saying every fire door has a universal legal 5–8 second closing time.
The manufacturer’s instructions and the particular doorset requirements take priority.
What I’m looking for is controlled movement.
The door shouldn’t:
- slam
- stop
- hesitate
- bind
- move excessively quickly
- fail to latch.
Then Test It From 15°
I also test the door from approximately 15° open.
Release it and watch what happens.
By this point the door has lost most of the momentum it had when it was opened to 90°.
That makes it a very useful test of the closer’s ability to complete the closing cycle.
There is also a practical reason I like this test.
People don’t always open doors to 90°.
Quite often someone will pull a door open just enough to get through quickly, slip through and let it go.
The 15° test therefore gives you a useful indication of how the door behaves in something closer to normal everyday use.
The current government fire-door guidance also specifies checking a self-closing fire door from around 15° and ensuring that it closes fully.
Backcheck
I don’t normally like interfering with backcheck.
In my experience, it should already be correctly set and I very rarely find a genuine reason to alter it.
If a door is unusually stiff to open and backcheck is genuinely contributing to the problem, then it needs investigating.
But don’t simply start adjusting it because the door doesn’t feel right.
Check the rest of the doorset first.
Any adjustment should remain within the manufacturer’s permitted settings and the requirements of the particular installation.
Don’t Speed Up the Closer to Cure a Bad Door
This is something I’ve seen far too many times.
The door doesn’t close properly.
Someone increases the closer power.
Then increases the closing speed.
Then increases it again.
Eventually the door slams shut.
The closer hasn’t fixed the problem.
It is just forcing its way through it.
I’ve seen doors slam hard enough to damage plastered walls.
You can sometimes see cracking developing around the corners of the frame.
And a violently closing door can create a dangerous finger-trap situation.
If you need to dramatically increase the closer to make the door work, stop and find out what the door is actually fighting against.
The Adjustment Screws Are Not a Magic Fix
Once you see a closer fitted incorrectly, you can often predict what has happened next.
Someone has attacked the adjustment screws.
I’ve seen them wound out so far that the closer starts leaking oil.
I’ve also seen them wound in so tightly that the adjustment slot has been chewed out.
That’s not proper adjustment.
That’s trying to make the closer compensate for a poor installation.
If the arm is wrong, fix the arm.
If the closer position is wrong, fix the installation.
If the door is binding, fix the door.
If the seals are creating excessive resistance, investigate the seals.
Don’t just keep winding the closer up.
Some of the Worst Closer Installations I’ve Seen
I’ve seen pretty much every possible mistake.
Closers:
- upside down
- back to front
- with the arm the wrong way round
- with the arm too high
- with the arm not properly fixed
- with incorrect preload
- in the wrong fixing position
- snagging the frame
- hitting the wall
- with completely wrong arm geometry.
And then there are the really imaginative ones.
I’ve even seen a closer fitted slap bang in the middle of the door.
I honestly don’t know how some people manage it.
Somehow, and almost beyond the laws of engineering, they have managed to get them to work.
I have to congratulate them for being so creative. 🤣
Fitting the Closer Cover
Another little job people forget is actually screwing the closer cover on.
It can be surprisingly awkward.
I find the easiest way is to get behind the door and use just the bit holder with the screwdriver bit and screw attached.
Not the drill.
Just the bit holder.
I find this gives me much better access and control than trying to get the drill into the restricted space.
🛠️ Professional Tip: Get behind the door and use the bit holder by hand. It’s a fiddly little job, but I find this much easier than fighting with the screw from the front.
And make sure the cover is actually secured.
Closers Need Too Many Tools
I’ve fitted enough closers over the years to think they require far too many tools to do what should be a fairly simple job.
You’ve got:
- drill
- drill bits
- screwdrivers
- different screwdriver sizes
- stubby screwdriver
- measuring equipment
- marking tools
- templates
- and sometimes another tool just to get into an awkward fixing.
I’ve always thought somebody should look at this from the installer’s point of view.
Why shouldn’t a closer be easier to fit?
Better access to fixings.
Fewer tools.
Simpler arm fitting.
Easier tensioning.
Less fighting with screws.
Sometimes the best product improvement isn’t making the mechanism more complicated.
It’s making the installer’s job easier.
🟧 Proudman Observation: I’ve fitted enough closers over the years to know that there is still plenty of room for improvement in the way they’re installed.
Final Fire Door Closer Checks
Before I leave the job, I want to know that everything is working properly.
Closer body
- Correct closer for the application
- Correct permitted installation arrangement
- Correct position
- Securely fixed
- Level
Arm
- Correct arm
- Correct fixing position
- Correct preload
- Correct tension
- Securely fixed
- Correct height
- No loose fixings
- No binding
- No fouling
- No wall contact.
Door movement
- Opens correctly
- Closes correctly
- No hinge binding
- No floor snagging
- No excessive seal resistance
- No latch interference
- No mechanical obstruction.
Closing performance
- Tested from approximately 90°
- Controlled closing
- Practical 5–8 second benchmark considered
- Tested from approximately 15°
- Door closes fully
- Door latches correctly
- No excessive slamming.
Double doors
- Both leaves tested together
- Correct closing sequence
- Selector/coordinator checked where fitted or required.
Finish
- Cover fitted
- Cover screw secure
- Adjustment screws undamaged
- No oil leakage
- Installation looks tidy.
Fire Door Closer Maintenance
Fitting the closer correctly is only the beginning.
A closer is a moving mechanical component and needs to continue working throughout the life of the doorset.
If the door becomes difficult to close in the future, don’t automatically assume the closer has failed.
Check the whole doorset again.
Building movement, worn hinges, changes in seals, latch resistance, air pressure and general wear can all change how much resistance the closer has to overcome.
For relevant residential buildings in England, fire-door checking requirements also include checking the self-closing devices as part of the required fire-door inspections. The frequency depends on the building and the regulations that apply.
Conclusion
Fitting a fire door closer isn’t just about getting the closer screwed onto the door.
The closer, arm, frame, hinges, seals, latch and door all need to work together.
Get the installation right first.
Make sure the arm is correctly positioned and preloaded, the frame fixing is secure, the arm doesn’t bind or snag and the door is free throughout its movement.
Then test it properly.
A door that closes from 90° is one thing.
A door that will still close and latch from around 15°, when most of the momentum has gone, gives you much more confidence that the complete system is working properly.
And if you’ve had to increase the closer because of new seals or another temporary resistance, don’t simply walk away and forget about it.
Book a return visit and check it again once things have settled.
I’ve seen too many closers used to compensate for problems that should have been fixed somewhere else in the doorset.
Get the door right first.
Then let the closer do its job.
🔥 Fire Door Closer Learning Path
Fire Door Closers
Fire Door Closers Explained
The engineering behind correct installation, adjustment and performance
Part 11 – Installing a Fire Door Closer
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Fault Finding Part 11 – Fire Door Closer Problems
Diagnose problems with closing, arm movement, seals, adjustment and closer performance.
Continue the Fire Door Installation Series
← Previous: Part 10 – Installing Fire Door Locks & Latches
Part 11 – Installing a Fire Door Closer
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Next: Part 12 – Measuring & Setting Fire Door Gaps →
🟧 Professional Tip
A closer should make a good door close properly — it shouldn’t be used to make a bad door work.
If you find yourself continually adjusting the closer, stop and find out what the door is actually fighting against.
That is usually where the real problem is.
