Installing hinges is something that probably should have appeared earlier in this series.

The reason I’ve left it until now is that most fire doorsets these days arrive pre-made and factory prepared. As doorsets become more common, I think actually cutting hinge recesses by hand is going to become less common over the coming years.

I’ve even seen some recent conversations among people in the trade suggesting exactly that.

There was a recent post along the lines of “sometimes it’s good to do it the old school way.”

Personally, I couldn’t agree more.

When I was teaching people, I always wanted them to learn how to do this properly with hand tools.

For me, if you can’t do the job without power tools, you’re not a complete carpenter or joiner.

I’m not saying there aren’t quicker ways of doing it, or that other carpenters don’t have their own methods. I’ve probably tried most of them myself over the years.

I’ve settled on this method because I find it quick, controlled and repeatable.

But more importantly, I don’t want this to become a lost skill.

You should know how to cut a hinge recess with a chisel.

So this is how I do it.

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Before You Cut Anything – Get Your Head Right

This might sound daft, but one of the things I do before cutting the hinges is actually go through the motions of putting the door into the frame.

I stand there and imagine picking the door up, moving it into the opening and putting it into position.

I almost look like I’m doing some sort of big fish, small fish dance.

It looks ridiculous.

But it works.

I got the idea from another joiner years ago and I’ve carried it on ever since.

I’ve taught other joiners to do it as well and I know some of them still do it.

The reason is simple.

If you cut the hinge recess into the wrong side of the door or frame, you can’t put the timber back.

So before I cut anything, I go through the motions and visualise:

• which end is the top;
• which side is the hinge side;
• which way the door is opening;
• where the frame is;
• where the door is;
• which blade of the hinge is going where;
• and which way everything is going to come together.

I keep doing it until there is absolutely no doubt in my mind.

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Know Your Hinge

A fire door hinge has two blades and a knuckle.

One blade is connected to the knuckle and the other isn’t.

I always put the knuckle-sided blade onto the frame.

The non-knuckled blade goes onto the door.

I do this every time.

It’s something you want to get into your head before you start marking anything out.

If you get the handing or orientation wrong and cut the recess into the wrong side, there’s no going backwards.

That’s another reason for doing the little visualisation routine before you start.

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Marking Out the Hinge

I always mark my hinges using a Stanley knife.

I want a sharp, clean line.

If you have to use a pencil, keep it extremely sharp and make the line as thin as possible.

Don’t create a big fat pencil line and then wonder which side of it you’re supposed to cut to.

I start by marking the position of the hinge.

I use a tape from the top of the door or frame and measure down.

I don’t draw the complete hinge outline at this stage.

I simply stab the timber at the top edge of the hinge position.

Then, when I come to actually mark the hinge, I put the blade into that little stab mark and push the hinge up tight against it.

This keeps everything tight and gives me the correct reference.

I then use the actual hinge to mark the recess.

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My Hinge Positions

I like consistency.

If I’m working with a 2040 mm door, I have set positions that I use rather than measuring every hinge from scratch every time.

The top edge of the hinges on the door is:

• 150 mm
• 932 mm
• 1717 mm

For a door lining with a 10 mm tranch/recess, my frame measurements are:

• 163 mm
• 945 mm
• 1730 mm

For a rebated door frame, my measurements are:

• 153 mm
• 935 mm
• 1720 mm

The frame measurements are taken from the inside head of the frame.

The door measurements stay the same.

The reason the frame measurements change is because the reference point changes depending on the frame arrangement.

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My Staff of Ra

I’ve got a piece of timber that I use for my frame fixing positions.

I’ve also put my hinge position information on it so I don’t forget the measurements.

I’ve called it my Staff of Ra.

Yes, it’s a bit daft.

If you’ve seen Indiana Jones, you’ll know where the name came from.

But it works.

It’s basically a simple reference staff that has my information on it, so I can work consistently without having to keep trying to remember every measurement.

I mainly use it for my frame fixing positions, but I’ve also put the hinge information on it so I’ve got everything there when I need it.

It’s not about avoiding checking.

It’s about having a repeatable system.

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Marking the Hinge Positions

I mark the hinge positions on the door first, all three at once.

Once I have the three positions marked on the door, I then do the same on the door frame, marking all three hinge positions before I start cutting any of the recesses.

For a standard 2040 mm door, my usual hinge positions on the door are:

• Top: 150 mm down from the top
• Middle: 932 mm down
• Bottom: 1717 mm down

For the door lining/frame, using a 10 mm tranch/recess, my usual positions are:

• Top: 163 mm
• Middle: 945 mm
• Bottom: 1730 mm

I mark the hinge itself rather than relying on a pencil line alone. I use a Stanley knife to score a sharp, clean line around the hinge position. When marking the long edge, I take a few passes with the knife to make the line clear and well defined.

For the top hinge position, I measure down from the top of the door or frame and stab the top edge position into the timber. I can then put the hinge into that mark and push it tight against it. This gives me a consistent starting point for marking the hinge.

I do this for all three hinges on the door first, then repeat the process for all three hinges on the frame.

Only when everything is marked out do I start cutting the recesses.

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Understanding the Grain

This is probably the most important thing I can teach somebody about chiselling timber.

Look at the timber from the side and imagine it is a book.

The pages run along the length of the timber.

The grain is doing the same thing.

You’ve effectively got lots of layers stuck together.

When you hit a chisel straight down into timber, you’re chopping across those layers.

The timber wants to split along one of those grain lines and the pieces can move left or right.

If you understand that, you can start controlling the timber rather than fighting it.

I always say:

Wood breaks at the point of least resistance.

Remember that.

It isn’t just useful for hinge recesses.

It should be one of the cornerstones of working with timber.

If the wood has nowhere to break into, it will find somewhere itself.

And we don’t want it deciding where that is.

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Use the Hinge to Give You the Correct Line

I use the clean internal line of the non-knuckled hinge blade as my reference.

That gives me the line I want to work to and the designed position of the hinge.

Offer the hinge up to the frame and door.

Keep it tight against your reference point.

Then lightly score the timber with the Stanley knife.

Take extra care along the long edge that runs with the grain.

This is the part that can sometimes decide to do its own thing.

I make a few passes with the knife to reinforce the line.

Don’t try to cut deeply straight away.

You’re building up the line.

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Use the Right Size Chisel

For this job, I like a 30–32 mm chisel.

Fire-door hinge blades are around that width, so it makes sense to use a chisel that allows you to work across the full width rather than using a much narrower chisel and creating loads of separate cuts.

But this only works if the chisel is sharp.

And I mean sharp.

We’ll come back to that.

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Reinforce the Marked Line

Once I’ve marked the hinge, I use the chisel to lightly reinforce the complete perimeter.

I’m not trying to chop the recess out yet.

I’m just breaking the surface.

Think about an apple.

All you’re doing is breaking the skin.

One light hit is enough.

This first cut is going to remain visible, so don’t destroy it.

You want a clean, controlled line that tells the timber where you want it to break.

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Don’t Start at the End

This is another important part of the method.

I start approximately 5–6 mm in from the end of the hinge recess.

I don’t start right at the end.

Remember the rule:

Break at the point of least resistance.

If you start right at the end, you’ve got nowhere for that piece of timber to break into.

Start a little way in.

Give the timber somewhere to go.

I make a controlled downward hit.

Then move along approximately 5–10 mm and do it again.

The second cut is where you start to see why this works.

The timber between the first and second cut now has somewhere to break into.

It can split back towards the first cut along the grain layer.

You then keep working along the recess in this controlled fashion.

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Work With the Grain – Don’t Let It Work You

When you’re working along the long edge, keep the edge of the chisel aligned with the long line of the back of the hinge recess.

Don’t start working along the grain with the chisel at an angle of around 27 degrees and allow it to start diving into the timber.

Once that happens, the grain starts deciding where the chisel goes.

You can suddenly be deeper than you wanted and following a grain line that you didn’t intend to follow.

That’s where you’ve lost control.

Keep the chisel controlled.

Your first cuts are about creating consistent depth, not producing the finished recess.

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Work Around the Corners

The corners are treated in the same way.

I use the same chisel and work around the complete recess, including the corners.

Don’t forget that the corner is part of the perimeter you’re trying to control.

The whole idea is to create a clean boundary around the hinge before you start removing the main amount of timber.

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Work Towards the Other End

Keep moving along the recess in your 5–10 mm steps.

You should start seeing little strips of timber breaking away.

Once you’ve worked your way along, you reach the other end.

At the end, I like to make the first hit lighter.

I want to see how the timber is going to break away.

Then I can make the second controlled hit and remove more stock, watching the edge as it breaks.

Then I go to the other end and repeat the process.

You should end up with lots of little strip pieces of timber coming away rather than one great chunk that you’ve just torn out.

That’s control.

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Remove the Timber

Once you’ve worked around the recess, remove the pieces you’ve created.

Have a look at what you’ve got.

If you’ve done it correctly, you shouldn’t have a massive amount left to remove.

Usually, I’m looking at around 1 mm or so to finish the recess.

This is where patience pays off.

Don’t start attacking it because you’re nearly finished.

You’re nearly finished — so slow down.

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Finish the Recess

Now I start using the chisel to get the finished recess.

I’ll reinforce the perimeter again, particularly along the long edge.

Then I use the chisel to take off the last tiny amounts.

With the bevelled side down, I use a very light angle rather than plummeting the chisel into the timber.

I’m taking off micro-millimetres.

When I’m coming from the recessed side, I can use the flat side down to help keep the chisel running flat rather than allowing it to dig in.

This is where a sharp chisel really comes into its own.

You’re not hacking timber away anymore.

You’re almost planing it with the chisel.

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Keep Checking the Hinge

Don’t assume you’ve got the depth right because it looks right.

Keep the actual hinge beside you.

Put it into the recess.

Check it.

Take it out.

Remove a little more.

Check it again.

You want the hinge sitting at a consistent depth all around the recess.

You don’t want an arch where you’ve gone deeper in the middle or deeper around the edges.

You can use the hinge itself to check this.

You can also use a 4 mm packer as a handy check.

The arrangement I use is:

3 mm hinge blade + 1 mm intumescent packer = 4 mm

The packer I’m using allows me to rattle it around the cut-out and check the edges for consistency.

It’s a simple way of seeing whether you’ve got the same depth around the recess.

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Get the Hinge Sitting Properly

You don’t want to see a gap behind the long edge of the hinge blade.

The hinge needs to sit properly into the recess.

If you’ve marked the recess correctly and cut it correctly, the hinge will sit where it is supposed to sit.

If you accidentally make the recess too deep, the hinge can disappear too far into the timber.

That can affect the position of the door.

For example, with a 44 mm door, you don’t want to create the situation where the hinge has been recessed too deeply and the door is effectively sitting as though it were a thicker door.

This is one of those simple mistakes that can cause problems later.

Get the hinge recess right in the first place.

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Predrill the Hinge Holes

Once I’ve completed the recess in both the frame and the door, I always predrill the screw holes.

I do this in both timbers.

That includes hardwood.

My usual drill size in hardwood is 3.5 mm.

I’m not interested in making the drill do as much work as possible.

I’m trying to make sure the screw goes in properly and doesn’t start chewing the timber or camming out the screw head.

I always predrill the holes off-centre.

I’m aiming into the frame or into the lipping rather than putting the hole dead in the centre.

There’s a reason for this.

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Why I Drill the Screw Holes Off-Centre

Look at the hole in the hinge.

The screw passes through the hinge blade and eventually reaches the chamfered part of the hinge hole.

I want that chamfer to help pull the hinge tighter into the timber as the screw seats.

So by positioning the hole correctly, the screw helps draw the hinge into the frame or lipping.

That gives you a much tighter hinge.

It also makes the job look much neater.

You should not be able to look along the long edge of the hinge and see daylight behind it.

The hinge should be tight.

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Use the Supplied Screws

With fire-door hinges, use the screws supplied with the hinge and specified for the certified arrangement.

I always make sure I’ve got more screws than I actually need.

There is a reason.

You can get screws where the stamping or formation of the head isn’t right, or you’ve got one that simply isn’t up to standard.

I don’t want to get halfway through a door and find I’m short.

The sizes I commonly work with are No.10 × 1¼” or 1½”, depending on the hinge/application.

Don’t substitute random screws because they happen to be in the toolbox. The screw specification is part of getting the hinge installation right and must follow the particular hinge/door certification and instructions. BWF guidance likewise states that the correct number, size and specification of screws should be used.

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The Hinge Position Has to Be Consistent

The positions of the hinges aren’t something I just guess.

Once you’ve got your established measurements, use them consistently.

But remember that small inaccuracies can add up.

I work with the frame position around a 3 mm offset to allow for the 3 mm head gap.

It doesn’t always end up exactly 3 mm.

Sometimes it ends up around 4 mm.

I think that’s simply because you can be half a millimetre out somewhere, the hinge can be half a millimetre out somewhere else, and suddenly all those little inaccuracies have added together.

That’s why the final installation still needs checking.

Your measurements get you there consistently.

They don’t remove the need to look at what you’ve actually built.

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Lift-Off Hinges

Lift-off hinges are handed, so check the handing before you start.

The same basic preparation method and hinge positions apply, but you need to make sure you’ve got the correct left- or right-handed hinge before cutting anything.

Again, this comes back to the door dance.

Know which way the door is going before you cut the timber.

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Intumescent Hinge Packers

Once the recess has been completely finished and smoothed, I add the intumescent hinge packer where it is required by the door’s certification.

In my method, I use the 4 mm check:

3 mm hinge blade + 1 mm intumescent packer.

The packer goes behind the hinge blade and the hinge is then fitted over it.

The actual requirement for intumescent protection depends on the particular fire-door certification and installation instructions, so don’t assume every hinge arrangement is identical. BWF guidance specifically says intumescent pads should be used under both hinge blades where the installation instructions specify them.

Once the packer is in place, put the hinge into the recess and screw it in.

The hinge should be sitting tight and flat.

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Sharp Chisels – I Can’t Stress This Enough

One of the most important things a joiner needs is a sharp chisel.

I can’t stress this enough.

I’ve even seen things get heated when a labourer picks up a joiner’s chisel thinking they can use it as a bolster.

It’s happened more times than I’d like to mention.

Don’t do it.

A joiner’s chisel is a precision tool.

I keep mine sharp all the time.

I always say:

“I’m giving them a tickle.”

I keep the sharpener close and continually give the edge a little tickle rather than waiting until the chisel is completely blunt.

That way I’m always working with a really sharp edge.

If you hit a nail and put a proper dent in the blade, you could spend an hour or more getting it back out.

Ouch.

It’s not a nice job.

That’s why I sharpen regularly.

A quick tickle is much easier than repairing a badly damaged edge.

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Old School Doesn’t Mean Slow

There are quicker ways of cutting hinge recesses.

There are routers, jigs and other power tools.

And there is absolutely a place for them, particularly when you’re producing large numbers of doors.

But I still think every carpenter and joiner should learn how to do this by hand.

Because once you understand:

the grain → the point of least resistance → how to control the break → how to control the chisel → how to finish the recess

you understand something fundamental about timber.

And that knowledge doesn’t disappear just because you’ve picked up a power tool.

I’ve probably used every method there is over the years.

This is the one I’ve settled on because it’s quick, accurate and controlled for the work I’m doing.

But it’s my method.

Other experienced carpenters and joiners will have their own methods, and that’s fine.

The important thing is that you understand what you’re doing and can produce a properly prepared recess without relying entirely on a machine.

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Final Hinge Check

Before I move on, I check:

• correct hinge;
• correct handing;
• correct blade on the frame;
• correct blade on the door;
• correct position;
• correct depth;
• clean corners;
• clean long edges;
• no gaps behind the blade;
• consistent recess depth;
• correct intumescent packer where required;
• correct screw specification;
• pilot holes correctly positioned;
• hinge sitting flat and tight.

And then I move on to the next hinge.

One at a time.

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Why I Still Teach This

Most modern fire doorsets are increasingly arriving factory prepared.

That’s a good thing where it gives you a properly manufactured and certified doorset.

But it also means there is a danger that traditional skills disappear.

I don’t want that.

If you’re going to call yourself a carpenter or joiner, I think you should be able to pick up a sharp chisel and cut a hinge recess properly.

You should understand why the timber breaks.

You should understand the grain.

You should understand how to control it.

And you should be able to do the job without reaching for a power tool every time.

That’s what being a joiner is about to me.

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Key Takeaways

• Check the door handing and hinge orientation before cutting.
• Always visualise how the door will go into the frame before marking the hinges.
• Put the knuckle-sided blade on the frame and the non-knuckled blade on the door.
• Mark hinge positions from the correct datum.
• For a 2040 mm door, my door hinge positions are 150, 932 and 1717 mm from the top.
• For a door lining with a 10 mm tranch, my frame positions are 163, 945 and 1730 mm.
• For a rebated frame, my frame positions are 153, 935 and 1720 mm.
• Use a sharp Stanley knife for clean marking.
• Use a 30–32 mm chisel where appropriate for the hinge blade width.
• Reinforce the marked line lightly before removing material.
• Remember the point of least resistance.
• Don’t start chopping directly at the end of the recess.
• Start around 5–6 mm in and work progressively along.
• Work in controlled 5–10 mm increments.
• Work around the corners as part of the same controlled process.
• Keep checking the actual hinge for depth and position.
• Use the 4 mm check where applicable: 3 mm hinge + 1 mm intumescent packer.
• Predrill both the door/lipping and frame.
• My usual hardwood pilot hole is 3.5 mm.
• Predrill off-centre so the fixing helps draw the hinge tight.
• Use the correct supplied hinge screws and have spares available.
• Don’t leave a gap behind the long edge of the hinge.
• Fit the required intumescent protection in accordance with the door’s certification.
• Keep your chisels sharp — give them a tickle.
• And most importantly, learn to do it by hand.

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Continue the Fire Door Installation Series

Part 8 – Fitting the Stop Lath

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Part 9 – Installing Fire Door Hinges

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