Position of mortice lock w.r.t tenon joint?

[l0n35t4r]

Hi,

I am about to install mortice locks on wooden doors made of some good quality teak. All the doors have tenon joints exactly at the recommended height of mortice locks/handles - between 900 MM to 1 M. So, I'll have install the locks little higher.

1) As I cannot touch the tenon joints, how much minimum spacing above the tenon is required to chisel out for mortice locks? Tenon joints are rock solid, and doors including the frame are 6.5 to 7 feet high.

2) Locks are standard Euro locks and the recess needs 17 cm long and 7 cm deep mortice. So, I guess one of the faceplate screws will dig into the tenon joint. I hope this is alright?

Thanks!

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[JohnD]

the lock needs to be well away from the M&T. I would guess a min of 50mm. A single screw in a tenon will not matter.

However you might consider putting the lock at shoulder height, where it will resist someone trying to force it.

In UK we commonly have a nightlatch 1/3rd down from the top of the door, and a deadlock 1/3rd up from the bottom. This is the strongest way, and resists both a kick and a shoulder. Similarly if you have a lock and a bolt, space them well.

If there is only one lock, then yes, about half-way up the height of the door, but in your case, avoid the M&T. If you are putting it lower, try to put it at about the height of your hand when you are standing, so you do not need to crouch to put the key in.

 

[big-all]

a minimum 40mm above the shoulder off the mid rail then you rule out the mortice having any steps
the shoulder is the point the square edge finnishes

 

[l0n35t4r]

Thanks guys for your suggestions. I've installed all the mortice locks high above the M&T joints.

I also wanted to install a night-latches but didn't know about the rule of 1/3rds and the bolt at shoulder position. I would've invariably installed some bolts at the shoulder position but didn't know about the logic behind it.

 

[foxhole]

Doors only get forced at shoulder height in movies, you would break your shoulder before most doors.

 

[JohnD]

unless they just have a Yale.

 

[l0n35t4r]

I remember that once I had to force open my main door as the lock was stuck. Door had steel reinforcements and a huge steel lock was welded onto it. I pushed hard with my shoulder and the wall gave away. Incidentally, the lock was at the shoulder height.

Now, this makes me think that having a bolt/lock at the shoulder height is not a good idea, as one can use full force at this position. That same steel lock was once welded at the bottom of the door with the dead bolt going inside the floor. I guess this option is good as no one can use their feet to force open such locks. lol . And the same applies to top most position. Door would simply sway but the lock wouldn't receive full impact of the blow. And it'll be quite attention grabbing if someone tries to pick a lock at the top or bottom of a door.

 

[Alarm]

Trick is as been told, equidistant. With lockguards, London and Birmingham bars with hinge bolts. A solid core door.

I prefer the Latch (dead latch) lock ( Not only Yale make them), central with the two mortise locks at the equidistants above and below.


Can be gotten around but its bloody hard.

 

[JohnD]

remembering of course that lots of householders CBA to operate one deadlock, never mind two

 

[Alarm]

Then you offer a keyed alike service.

Not my fault if they dont lock up when they pop to the shops. Which is the biggest time these things happen.