How can I install modern locksets on these interior doors?

Question

I've recently bought my first house which I'm very excited about, got into the decorating phase and decided to replace the door handles - some of which were damaged - with nice new ones. Being a definite rookie when it comes to DIY, I was pretty much unaware of the problem I'm having was even a thing, so I apologise if I've made mistake 101 in this situation.

The problem I have is that the old hole that has been cut into the door through which the old door handle fitted is too near the edge of the door for the new mechanisms, which basically means the old mechanism was 4.5cm deep, and the new handles are (approx) 6cm deep. I've since been told that the barrel for a door knob rather than a door handle needs to be longer so that you don't hit your fingers when opening them.

I am primarily looking for advice on the best way to solve this, and if there is anything I definitely shouldn't do.

The suggestions I have received from friends and family so far have been options between

• Use the old latch mechanism - however some of them are damaged, and the bathroom doors had a secondary locking mechanism, so these doors have 2 holes.
• Drill further into the existing hole as deep as this one needs to go (parallel to the door), fill the existing hole (perpendicular to the door), and then drill into it where the new hole needs to go as normal
  • or alternatively do not fill in the perpendicular hole, and use the door knob itself to cover where the old hole was
• Completely fill this hole in, and start from a new position - I hadn't even realised since just now that the hole is not central to the middle section of the door

Personally my option was to fill in the perpendicular holes with some 1" wood, and effectively start from there.

Answer 1

You're going to have to drill a larger hole for the new handles, which should completely encompass the old hole.

Head on down to your local hardware store (or cruse the internet), and look for a door handle installation jig like this Irwin® Door Lock Installation Kit

^{Example only, these jigs are available from many different manufacturers}

It comes with the proper size hole saws to set up a door for modern locksets, and makes alignment of the holes quick and easy. Simply attach the jig where you want it, and drill the holes with the supplied hole saws.

Answer 2

This isn't a very "DIY" answer but I think it certainly applies in this case...

Call a door shop in your town and have them drill the door for your lockset. This will be slightly more expensive than buying the jig and doing it yourself but what happens if you screw up one of your doors?

Once it's drilled by a pro, you can get your DIY-fix by remounting, shimming and installing the lockset.

On the other hand, if they are just typical 6-panel doors that are easily replaced then you can give it a shot... worst case scenario then is that you replace the door, which should be under $100.

Answer 3

Looks like these doors used to have mortise latches, where the mechanism is inserted into a cavity in the edge of the door and only the knob shaft (and keyhole, if there is one) extend through the door's face.

If you can get the exact dimensions, new mortise mechanisms are still available to replace many of the older ones, and/or the old ones can be cleaned (and springs replaced if necessary) to make them work pretty much like new. And if you just want new doorknobs, new square-shaft knobs are still available to replace the old ones.

That would be my preference, from a stylistic point of view. It's a nice traditional old door; you can let it continue looking like a traditional door, just one that's bright and shiny. I'm considering that as one of the options for my library door.