How to add a third hinge to an existing steel door frame?

andrewlyons

I'm looking to replace some internal doors to the original (1990s) steel frames.

We currently have hollow core doors and they're falling apart and, with a new baby just arrived we'd like to avoid waking our older child. We're considering a solicore door like the Hume SCX1 as its sound properties are better.

All of the doors in our house are currently hollow core doors in steel frames. They only have two hinges and all of the newer doors we've looked at are heavier and require three.

I've never looked into hinges on steel door frames and I'm not really sure where to start with adding or replacing them. The existing hinges look fine - a bit dirty but fine otherwise. I can't see any way to remove the existing hinges, and they're attached inside the frame.

Would I be best to use an angle grinder to cut out another slice in the frame, and rivet a new hinge in somehow? Or use a flush mount the hinge and use steel screws, but would this cause an issue with the existing hinges because of the gap difference?

MitchellMc

Hi @andrewlyons,

You're correct that most modern solid core doors, including the Hume SCX1, are considerably heavier than hollow core doors and are typically hung on three hinges. While it's not impossible to hang them on two hinges, I'd recommend adding a third to better support the extra weight and reduce the chance of the door sagging over time.

From your photos, it appears you have a pressed steel door frame with welded-on hinge leaves. Unfortunately, there isn't a simple way to remove or replace them, and I certainly wouldn't recommend cutting into the frame with an angle grinder to try and weld or rivet in another hinge. That would be quite difficult to do neatly and could compromise the finish of the frame.

A much simpler approach would be to use a surface-mounted hinge for the third hinge. It can be fixed directly to the face of the steel frame using self-drilling metal screws or rivnuts if you prefer a stronger fixing. Since the existing hinges are already supporting the door in the correct position, the slight offset created by a surface-mounted hinge generally isn't an issue, provided it's fitted carefully so it only comes into play once the door is hung.

Can I also ask what size doors you're replacing? If they're standard 2040 x 820mm doors, that will help determine just how much additional weight you're dealing with. If it's a smaller solid-core door, you might get away with just the two hinges.

Let me tag @Nailbag to see if he has any thoughts.

Please let me know if you have any questions.

Mitchell