How can I eliminate flex in door jamb?

[Jay Aubuchon]

If the door pictured below is locked, and someone pulls quite hard on the outside handle, the door jamb will flex inward. There must not be good blocking behind the catch. I haven't tested to the extreme, but a hard enough pull might well cause enough flex to open the door.

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I would like to eliminate, or at least greatly reduce, this flex without disassembling the door frame. Any suggestions? For example, is there something that could be sprayed or injected through a small hole and would then harden sufficiently?

[Paul F Franklin]

I don't think there's anything you can inject that will help much. You need fasteners that run through the Jamb into the framing behind it, whether it's wood or block or ?. Given that the jamb is flexing inward, you could replace the screws holding the latch with ones long enough to reach the framing. Or just install new long screws above and below the latch. If there are no shims behind the latch, you can still do this, you will just have to stop driving the fasteners when the jamb starts to get pulled toward the framing. The screws will still resist any force that tries to pull the jamb away from the framing. Normally there are shims a couple of inches above and below the strike, but if that panic bar was added later on the shims might be lower down by the strike for the knob. Obviously the best way to do this would be to remove enough trim to allow putting in the proper shims, but if you don't want to do this, the above should at least help.

[Alex Zeller]

My advice would be to use fully threaded #10 wood screws so they screw into both the wood jamb and into the stud behind it. As long as the wood the jamb is made from is strong enough it will not be able to move.

[Maurice Mcmurry]

The Great Stuff Pro foam gun comes with plastic reducer tips that are about 3/16. You can squirt foam into a screw hole and replace the screw without over tightening. It is tricky to get just the right amount of foam behind the jamb. Making a big mess and bowing the jamb can occur. The foam is not very strong but will resist compression. I would not try it with a straw type, one time foam can. Experimenting with the gun and foam expansion rate and having acetone for cleanup would be helpful.

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[Jay Aubuchon]

Just to clarify, by “inward,” I meant toward the frame.

[Maurice Mcmurry]

Jay, Is that a block wall? You could remove the strike for the lower door knob, open up the 7/8 bolt hole and use a grout bag to squeeze in some non shrink grout. As well as opening up the caulk joint between the jamb and plaster and tuck pointing.

[Jim Becker]

Just to clarify, by “inward,” I meant toward the frame.
I'd likely pull the trim and put in additional shims/blocking to stabilize the structure. That and insure that the proper type and length of screws are used as was mentioned in other commentary.

[John TenEyck]

You might try adjustable jamb screws. https://www.amazon.com/U2-Fasteners-T00103125B-Topstar-500-Pack/dp/B09X6D7Q3R?ref_=ast_slp_dp

John

[Scott Clausen]

Some trim needs to come off and firm filler to shore up the jamb is needed. May also be possible to add a filler plate to shim out the rim latch. If the flex is not huge the shim may work.

[Maurice Mcmurry]

I do not see any trim in Jays Image.

[James Dempsey]

His picture shows what appears to an applied stop made from wood on a flat jamb. The trim is assumed to be off to the right of the picture.

[Jay Aubuchon]

I do not see any trim in Jays Image.

Exactly right. The drywall or, more likely, plaster goes right up to the jamb. There is no trim to remove. To get behind there, I would have to pull the jamb away from the framing or break open the wall. Neither is appealing. If it were a simple matter of removing some casing and inserting normal blocking, I would certainly do that.

But you all have given me some good food for thought. Thanks!

[James Dempsey]

Could you pull the shim from your strike and have a piece of 12ga CR behind in place of it wodth of you frame and 12" high with screws at the corners to reinforce.

[Jay Aubuchon]

Jay, Is that a block wall? You could remove the strike for the lower door knob, open up the 7/8 bolt hole and use a grout bag to squeeze in some non shrink grout. As well as opening up the caulk joint between the jamb and plaster and tuck pointing.

I am 99.9% certain that the wall is typical old wood frame construction, with board sheathing on the outside and plaster over rock lath on the inside. But your ideas still seem worth considering. Thanks!

[Jay Aubuchon]

Could you pull the shim from your strike and have a piece of 12ga CR behind in place of it width of your frame and 12" high with screws at the corners to reinforce.

I think that this is what Scott Clausen meant by his suggestion of a filler plate. In any case, I like this idea a lot. The strike is of necessity shimmed out quite a bit. Replacing that with a long piece of steel might do the trick.

[Keith Westfall]

Pull off the striker plate and see if you might be able to drill a hole (as big as you can) and then glue in a length of dowel flush to the back of the striker plate. Put the striker back on and it shouldn't be able to move at all.

[John TenEyck]

This is the function of the adjustable jamb screws I mentioned earlier. Nothing could be easier for this exact problem.

John

[Maurice Mcmurry]

This is the function of the adjustable jamb screws I mentioned earlier. Nothing could be easier for this exact problem.

John

Here are the screws John is recommending in a more affordable quantity. I have it bookmarked for the future.

U2 TOPSTAR SCREW 1/4 - 3/8 X 3-1/8 18 PCS (T00103125H) (https://www.ustoolandfastener.com/u2-topstar-screw-1-4-3-8-x-3-1-8-small-pack-18-pcs-t00103125h/?gclid=Cj0KCQjw5ZSWBhCVARIsALERCvydDYJSNrCu4CoPMob Q7HH3J71KE59UV-oQh4i2gjUpuK8Aby-7EHMaAr8_EALw_wcB)

[Jay Aubuchon]

My advice would be to use fully threaded #10 wood screws so they screw into both the wood jamb and into the stud behind it. As long as the wood the jamb is made from is strong enough it will not be able to move.

I took off the strike, drilled a 3" deep pilot hole with countersinking, and drove in a #9 fully-threaded wood screw, taking care not to pull the jamb toward the stud, and then replaced the strike. This worked very well.

There were several attractive suggestions. The adjustable jamb screw were quite appealing, but rather expensive when accounting for the special driver and shipping. So I decided to try the cheap and — for my purpose — more or less equivalent method first.

Thanks for the help!

[Maurice Mcmurry]

Good job! I hope it works well. The door looks like it is in a commercial or public space.

[Doug Garson]

How about adding an "occupied/unoccupied" sign to the door? Having a bathroom door that can be locked from inside and is as secure as Fort Knox, OK exaggeration, is not a good idea. But the point is how secure does a bathroom door need to be? Sometimes the solution is to realize what the problem really is. For most of us knowing the bathroom is occupied is all that's required, most of us (I hope) won't try to force the door open if we know the bathroom is occupied. Translation for my southern friends, bathroom is the same as restroom :).

[Myk Rian]

How about adding an "occupied/unoccupied" sign to the door? Having a bathroom door that can be locked from inside and is as secure as Fort Knox, OK exaggeration, is not a good idea. But the point is how secure does a bathroom door need to be? Sometimes the solution is to realize what the problem really is. For most of us knowing the bathroom is occupied is all that's required, most of us (I hope) won't try to force the door open if we know the bathroom is occupied. Translation for my southern friends, bathroom is the same as restroom :).
What bathroom do you speak of?

[Jay Aubuchon]

This is the back door to a homeless shelter. They bought the building in December 2021. I’m their volunteer handyman. Just trying to keep things patched up until major renovations, which probably won’t start until fall.

https://www.outofthecoldcc.org/

[Doug Garson]

What bathroom do you speak of?
OOPs, somehow I got the impression it was a bathroom door, looking back at the original post and the OP's latest post I see I was mistaken. Classic example of why you shouldn't ass u me.
And to Jay, good on you for volunteering. My wife and I, well her more than me, volunteer for a food bank. One of our clients today said thank you for keeping me alive, I couldn't afford my medications without the food you give me. Needless to say, we were all moved by her statement. I encourage all of you to give back if you can if for no other reason than it will make you feel good.

[Tom M King]

Sounds good. If it's still not quite as secure as you would like, I'd take the strike off, drill a hole large enough to get the end of anchor setting epoxy nozzle into the hole with a tight fit, and squeeze some of the epoxy behind the jamb. The screws you installed will keep the jamb from closing up, and will let the epoxy fill as much of the void as possible.

You can find the anchor setting epoxy where the concrete is in box stores. Make sure you get the nozzle with the tube. The epoxy mixes in the nozzle, but that leaves the nozzle as a one use only.

It's very thick, so will not do much sagging behind the jamb, but will greatly reinforce the two screws.

I use it for many things other than its intended use.

[Jay Aubuchon]

… anchor setting epoxy …

It's very thick, so will not do much sagging behind the jamb, but will greatly reinforce the two screws.


Thanks! I’m guessing that the high strength version would suffice, as opposed to the super strength.

[Tom M King]

Yes.......

[Ole Anderson]

Shims and long screws.

[Scott Clausen]

I can remember in the early days of "Great Stuff" I watched a contractor foam all of the windows to make the house tight. You could not move any of the windows due to expansion. I think they make a non expanding version now too. If you use regular "a little dap will do ya"

[Jim Becker]

I can remember in the early days of "Great Stuff" I watched a contractor foam all of the windows to make the house tight. You could not move any of the windows due to expansion. I think they make a non expanding version now too. If you use regular "a little dap will do ya"
Yes, for doors and windows as well as any other "delicate" areas, the low expansion foam is essential. The regular stuff really has a lot of "power" to bend things as it expands.