Sizing a mortice lock/latch

IM

Morning all.

We have a set of timber doors in our porch, which we never close, because they only have small leaded windows, and shutting them makes an already dark hallway really gloomy. In any case the historic door furniture was removed years ago, so there's no latch with which to keep them shut.

They are pretty though, and part of the (1930s) house's character, so I'm looking to give them a fresh coat of paint and recommission them as functioning doors.

What I'm struggling with is the size of latch I need, to fit the legacy gap (or even, if I'm honest, what search terms to put in to a website - is it a latch, a lock, a sashlock...?) as they seem to be listed with one dimension - say 4" - when there seem to be any number of variables, and not every site includes dimension diagrams.

Ignore the fact that it's not to scale, and bear in mind that the measurements are not necessarily 100% accurate, but is anyone able to translate my diagram? Does it equate to a standard size, or will I need to search specialist historic homes' suppliers?





Frankly, if it's too hard/costly to find a latch that fits, I'll probably just do a cosmetic job, and add some new handles. At the end of the day, it's unlikely they'll be shut very often, and it's more about them looking pretty - but it would be nice to have them (theoretically) functional.

Mutton_Geoff

It's a mortice sashlock. The proper way to do this is fill the old hole with a cut block of wood glued in securely then router a new hole to fit your new lock exactly. Any space inside the door if fitting a new lock in the old hole severely weakens it.

Does your insurance ask for BS standard 5 lever or multipoint locks on all external doors. You might want to let them know of your current arrangement as any burglar could let themselves into the porch, close the door behind them and take their time accessing the internal door.

Bendy_House

Nice doors indeed.

You don't have any photos to show the style of previous handle?

To make these doors actually lock shut, you'd also need to secure the first door in place using a slip-bolt(s) or similar. The second door will then lock to the first using that mortice lock.

Surely there is every chance you can get a new sashlock to fit without having to go to MG's full extent - I presume you want to DIY this, and easily?!

Are these the actual dimensions that will fit, IM - the example lock you've shown? As you undoubtedly know, the backset is one of the more important dims. The distance betwixt the handle and lock will tend to be pretty standard, so that shouldn't be an issue, but check. And then there's the general body and faceplate dims. How close can you get?

I have black cast handles on my internal doors which I think might suit your doors. And matching security slip bolts on the front door, for largely decorative reasons.

What is the actual 'measuring' issue you have?

When it comes to painting your doors, I can recommend (thanks to suggestions on here) Zinsser AllCoat 15-year satin paint, water-based. Clean up the doors, soak any bare wood in wood preservative, and then apply the Zinsser in cool weather (the only issue I had was painting some windows in direct blazing heat.) The first coat acts as a primer - yup, you can apply it straight on to pretty much any substrate, including bear wood! - and subsequent coats go on beautifully.

IM

Mutton_Geoff said:

It's a mortice sashlock. The proper way to do this is fill the old hole with a cut block of wood glued in securely then router a new hole to fit your new lock exactly. Any space inside the door if fitting a new lock in the old hole severely weakens it.

Does your insurance ask for BS standard 5 lever or multipoint locks on all external doors. You might want to let them know of your current arrangement as any burglar could let themselves into the porch, close the door behind them and take their time accessing the internal door.

Oh now.... That's opened a whole world of thoughts I'd not had before 

IM

Bendy_House said:

Nice doors indeed.

You don't have any photos to show the style of previous handle?

To make these doors actually lock shut, you'd also need to secure the first door in place using a slip-bolt(s) or similar. The second door will then lock to the first using that mortice lock.

Surely there is every chance you can get a new sashlock to fit without having to go to MG's full extent - I presume you want to DIY this, and easily?!

Are these the actual dimensions that will fit, IM - the example lock you've shown? As you undoubtedly know, the backset is one of the more important dims. The distance betwixt the handle and lock will tend to be pretty standard, so that shouldn't be an issue, but check. And then there's the general body and faceplate dims. How close can you get?

I have black cast handles on my internal doors which I think might suit your doors. And matching security slip bolts on the front door, for largely decorative reasons.

What is the actual 'measuring' issue you have?

When it comes to painting your doors, I can recommend (thanks to suggestions on here) Zinsser AllCoat 15-year satin paint, water-based. Clean up the doors, soak any bare wood in wood preservative, and then apply the Zinsser in cool weather (the only issue I had was painting some windows in direct blazing heat.) The first coat acts as a primer - yup, you can apply it straight on to pretty much any substrate, including bear wood! - and subsequent coats go on beautifully.

Yes, there was a bolt in place when we first moved in. I vaguely remember taking it off, with a view to polishing it up. Presumably it's in one of those 'safe' places you only find two days after buying a replacement... :-) 

I don't remember what handles there were (if any). I think there may just have been a rather naff 1950 plastic finger-plate covering the holes.

Was thinking something like this - https://amzn.eu/d/f4jZMYX

In terms of the measurements, all I meant when I said they may be inaccurate was that I may be 1 or 2 mill out. So where I've (for example) said it's 55mm to the centre of the handle, and a standard sized one is 57mm there's every likelihood that that's the one I'm after.

TBH, given that I don't need the doors to be functional (notwithstanding my worries off the back of Mutton-Geoff's post...) I may just screw handles on, knowing they'll be left permanently open - not unlike the 'shutters' you see which are screwed to the side of the house, and never close around a window.

Will definitely look at that paint - thanks for the tip.

travis-powers

Have you tried Ironmongery direct?

Bendy_House

IM said:

Yes, there was a bolt in place when we first moved in. I vaguely remember taking it off, with a view to polishing it up. Presumably it's in one of those 'safe' places you only find two days after buying a replacement... :-) 

I don't remember what handles there were (if any). I think there may just have been a rather naff 1950 plastic finger-plate covering the holes.

Was thinking something like this - https://amzn.eu/d/f4jZMYX

In terms of the measurements, all I meant when I said they may be inaccurate was that I may be 1 or 2 mill out. So where I've (for example) said it's 55mm to the centre of the handle, and a standard sized one is 57mm there's every likelihood that that's the one I'm after.

TBH, given that I don't need the doors to be functional (notwithstanding my worries off the back of Mutton-Geoff's post...) I may just screw handles on, knowing they'll be left permanently open - not unlike the 'shutters' you see which are screwed to the side of the house, and never close around a window.

Will definitely look at that paint - thanks for the tip.

Nice - a large 'knob' style will be very much in keeping.

I think the mortice lock measurements were originally imperial, so 57mm would be a twoandaquarterinch backset. 55mm might be a rounding-down, or just to the back surface of the front plate, if you know what I mean :-)

I think you can be confident it'll fit just fine.

If you find the front decorative plate sits in a mm or so too far, just shim it behind the securing screws with an appropriate washer or similar.

The Zinsser paint also comes in gloss finish, if you prefer. (And matt, but hey...)

BUFF

If the dimensions on the lock diagram are correct (within 1 or 2mm tolerance) then a traditional, imperial 3" sashlock will give you the correct backset (distance between lock face & the centre of the handle spindle). There will be slight variations in case dimensions between manufacturers but nothing major (again usually 1-3mm) so easy to tweak the pocket.

It looks like you will also need a rebate set.

fyi
a latch will normally be a sprung bolt with an angled face & operated only by the handles
a deadlock will normally have a (usually heavier) flat faced bolt operated by a key
a sashlock will have both

Bendy_House

Lock size and backset - quite different, just to confuse matters (I was...)

john.h

You will also need a rebate kit