85mm Hinges on Solid Door, Ok or Dangerous?

[3Days]

I've purchased a new external door to replace where someone had an internal door for the entrance. The problem I have is the original two hinges, top and bottom are 85mm and already recessed into the jamb.

The question is, could I get away with using those 85mm hinges on the new solid door and adding a 100mm one in the middle? Is this legal and safe for both people and the frame's integrity?

I don't want to replace the jamb.

Any help welcome for this newbie. Thanks.

[addo]

Might look odd to curious eyes, but otherwise no worries. You'll possibly have to fiddle a bit to make sure the centre hinge is swinging in the same axis as the other two. Use a straightedge to check all this, not outright measurement off the jamb.

Also be sure that the fixings are adequate (not going to strip out). I recycled a front door from a 1947 house that had raised four boisterous kids, yet never slumped on its three 85mm hinges - only three screws per leaf!

Regards, Adam.


p.s. The "frame" is a jamb.

[3Days]

Also be sure that the fixings are adequate (not going to strip out). I recycled a front door from a 1947 house that had raised four boisterous kids, yet never slumped on its three 85mm hinges - only three screws per leaf!

Thanks for the reply Addo. I might just go with three 85mm hinges then. I was relalyl worried about the door maker asserting to use 100mm ones. I thought this maybe a regulations issue or 85mm hinges are just too weak.

p.s. The "frame" is a jamb.

arrr I was a little confused. I thought the frame was called a jamb, but then I got confused with it being referred as the door stops with others.

So a door jamb fits into the door frame of the house's structural wood?

[addo]

Semantically, I'd say the jamb is fixed into a framed opening.

The door maker probably is just covering their rump. Always allow for the "idiot factor". Will someone stand on a table to reach a lightbulb, will kids swing off your new door, will that handy-looking joist in the garage roof be used to hoist out a motor?

Worst case - if it starts to let go - swap all three hinges for four inch jobbies. But it's unlikely, especially if you put a squeeze of glue in the jamb screwholes upon final assembly.

Cheers, Adam.

[rumplestiltskin]

Regarding 85mm or 100mm hinges on a solid door:

It won't make any noticeable difference as long as the existing hinges are in good nick and the fixing screws are secure. If you were really concerned about the weight, then a second hinge directly below the top hinge will help alleviate any problems with the hinge tearing out of the jamb.

A few things.

Thing 1: The bottom hinge takes most of the downwards load. The top hinge keeps the door vertical, and the middle hinge helps to keep the door from bowing.

Thing 2: It is very important to keep the centreline of the hinges the same on all 3 hinges. The existing hinges will already line up, so make sure any additional hinges are on the same pivot centreline. If the pivot centreline is not the same, then the new hinge will bind at some point in its travel as the door tries to pull it into line with the other hinges.

Thing 3: Always store new doors flat (will bow, warp or cup otherwise) and pay particular attention to sealing the top and bottom edges with a suitable primer/undercoat. Otherwise they soak up moisture like a sponge and will end up delaminating or rotting before you get your money's worth.

Hope this helps

Dan

[les88]

You didn't say if the door jamb was steel or timber, if timber I would use 100mm hinges, fill the old screw holes by gluing in a timber plug. If the jamb is straight I would fit a middle hinge By using slip pin hinges it is easier to handle the door
les

[echnidna]

It would be more practical to use 3 new hinges as the pins will line up easier.
As the existing hinges are 85mm, which are adequate, I'd go with all 85mm hinges

[sports fan]

solid core fire doors and doors over 2040 in height are required to be hung on three 100mm hinges.. it wouldnt hurt the door in your situation either !

[Shannon Nash]

I don't want to teach my grandma to suck eggs if she already knows but sitting your new door on its edge next to the old door and using a square to mark directly off that door will mean that the hinges will line up perfectly when you hang the new door. It will also be easier to line up the axis of the three hinges with the door in this position as it is really important as pointed out by others already. The door can then be hung lightly by the top and bottom hinges while the mortice position on the door jamb is accurately laid out.

It is a bit of fiddling but means that you get it right 1st time. It is also easire to paint and therefore properly seal top & bottom like this.

Good luck.

SN

[Jarrahrules]

I don't want to teach my grandma to suck eggs if she already knows but sitting your new door on its edge next to the old door and using a square to mark directly off that door will mean that the hinges will line up perfectly when you hang the new door. It will also be easier to line up the axis of the three hinges with the door in this position as it is really important as pointed out by others already. The door can then be hung lightly by the top and bottom hinges while the mortice position on the door jamb is accurately laid out.

It is a bit of fiddling but means that you get it right 1st time. It is also easire to paint and therefore properly seal top & bottom like this.

Good luck.

SN

Well done SN I have been a carpenter for 15 years and still do it this way. It also helps to paint the hinge rebate.
jamc