Beefing up door: Frame to Stud question

#1

At some point in the future I plan to beef up a door in the manner of the Rod Gervais superdoor. I mentioned this on my build thread and Stuart mentioned the requirement of strengthening the studs the door frame is attached to, to deal with the extra weight. He posted some photos of examples in that thread, very useful;

viewtopic.php?f=5&t=8&p=1359#p1359

That's a bit in the future, but in the meantime I took off the door architrave to optimise the seal and also to see what lurks beneath. I should have done this before, as it revealed some gaps right through from one side of the frame to the other. The architraves were on pretty flush so sound leakage probably not as bad as it could be, but still, doh! I misunderstood the method of how door frames are attached to studs. I thought the frame would be screwed flush to the studs, but of course it is not. There is a tolerance gap most of the way round. You live and learn :-)

I'm going to stuff the gap with insulation and seal both sides with backer rod & caulk. I've already fitted a drop seal at the bottom. The gap at the top is almost an inch wide so I'll pad that up a bit with some wood to get a smaller gap to caulk. In the UK the caulk should be intumescent stuff as it's a fire door. No worries there.

Here's a photo of the door. The blue masking tape indicates the position of large screws holding the frame to the stud. According to a construction document about fitting these, 5 is the correct number for a door of this type (mass 45kg);

It brings to mind several questions that would be useful to know before I seal these gaps up:
1) If I beef up the door by adding mass, should I add some extra screws of this type? The current screw threads are at least 5mm in diameter, and if done properly will penetrate 70mm in to the stud.
2) The fitting document (generic) said there should be a "packers" of similar material to the frame in the gap between frame and stud. These should be positioned with the screws going through them. At the moment there are some bits of plastic serving this purpose at two points, not five. Worth doing properly do you think?
3) The fitting document showed two screws in the top of the frame going to the stud above it. This door has none. Should there be? As a starting point I intend to have a look at this part of another door to see how it is done there.

Any thoughts would be most gratefully received.

I eventually intend to improve the wall by adding resilient clips and hat channel. So the frame will presumably have to be widened on one side to bridge the larger cavity. It might mean breaking one side of the aforementioned backer rod & caulk seal to avoid a tiny wee triple leaf, but that's no big deal. It's some time away and I'm happy to enjoy the improved isolation in the meantime :-)

Cheers and thanks again!
Jennifer

#2

Greetings Jennifer,

The fitting document (generic) said there should be a "packers" of similar material to the frame in the gap between frame and stud. These should be positioned with the screws going through them. At the moment there are some bits of plastic serving this purpose at two points, not five. Worth doing properly do you think?

Yes, this makes for a SOLID fitting door within the frame.

Having just help hang one exterior door and two solid-core interior doors (during a house remodel), the "packers" of which you speak are generally wooden shims. Here in the states the home improvement centers sell packs of them in the lumber aisles. Because they vary in thickness, you can use them singly or in combination to get a good fit. Fit them, score with a utility knife, and snap off the excess. Easy-peasey (except for lifting the solid-core door).

All the best,

Paul

#3

Thanks Paul, that is most reassuring to know. I have a box of wood offcuts of various thicknesses that will do most of it I think. And by coincidence some packing wedges arrived in the post today. They're for another purpose but there will be 10 left over for this task :-)

These doors really are heavy aren't they. The FD30 ones are no lightweights, but we have an FD60 going to the built in garage and it is a beast to remove! I fitted a heavy duty drop seal to it, proper good sound isolation right enough.

Cheers,
Jennifer

#4

Adding to what Paul said:

The reason why there's always a gap between the rough opening in the framing, and the actual door framing (or "casing", depending on country), is because framers are not accurate, and framing is not accurate!

So the rough opening won't be plumb, square or straight, and thus won't match the door unit, which is all three of those! So the RO is bigger than the door unit, usually by 1/4" on each side, sometimes more. That gap gives you space to wiggle the door around inside the rough opening, until it is square, plumb, and straight. You do that using a spirit level and the shims that Paul mentioned: drive the shims into the gap at the right spots to get everything looking nice on the level, then anchor it in place to the RO framing.

The problem for studios is that the shims only fill a small part of the total gap! Just enough to provide good support, and keep the door plumb. But the rest is empty air. You can, indeed, fill it with backer rod and caulk, but I prefer to put in even more shims first, inserted to be snug and firm, filling more of that gap, then do the rod-and-caulk thing over that. The reason being that studio doors are a lot heavier than typical hollow-core house doors, so they need even more firm support. So I put shims at least where the hinges will be, and where the latch will be, and at the top and bottom of the side frames, and anywhere else that will fit. Then seal. Wherever an anchor screw goes through, there is also shim behind that. In other words, each anchor screw goes through a shim.

1) If I beef up the door by adding mass, should I add some extra screws of this type? The current screw threads are at least 5mm in diameter, and if done properly will penetrate 70mm in to the stud.

Any place you will have a hinge, make sure there is an anchor screw close to that location, and with shim in the gap in that region, so there's a good solid connection. Don't put the anchor screw exactly at the spot where the hinge will be (unless you counter-sink it deeply), as you will need to route out (or chisel out) the wood where the hinge plate will be. And if you do have an anchor screw there, that's a problem! Either the hinge wont sit flat because the screw is sticking up under it, or the screws in the hinge plate will hit the anchor screw... So offset the anchor screws just beyond the hinge region, but close.

And don't forget to use enough hinges! Recently I posted on another thread some pics of a studio door that was hung incorrectly with not enough hinges, and the result was that the wood cracked, right where the hinge screws go into it, due to the heavy forces on those screws. Maybe you saw those photos?

2) The fitting document (generic) said there should be a "packers" of similar material to the frame in the gap between frame and stud. These should be positioned with the screws going through them. At the moment there are some bits of plastic serving this purpose at two points, not five. Worth doing properly do you think?

Oh yes, definitely! You MUST have shims where the screws are! If not, then you'll warp the door frame slightly, from the pressure of the screw on the frame with nothing behind it. I would pull those screws, put shim in, then replace the screws again.

3) The fitting document showed two screws in the top of the frame going to the stud above it. This door has none. Should there be? As a starting point I intend to have a look at this part of another door to see how it is done there.

Whaaa??? There's no header (lintel) above the door???? How on earth did that pass inspection??? Or maybe I'm not understanding right.... Are you saying that your door does not having anything in this location? Just empty space?

Nothing that you can nail your doorway top frame too?

If that's the case, then you have a little problem...

I'm hoping I just misunderstood you, ...

- Stuart -

#5

Thanks Stuart, I know everything necessary now to make this proper before putting it all back together.

I explained the woodwork at the top of the door badly, sorry. I meant no screws, not no header. There is indeed a stud running along right above the top of the door frame. I could screw the top of the door frame into this, with packers, no problem at all.

The gap is just the usual tolerance for fitting gap you spoke about. It's almost an inch here though, wider than on the sides. I had planned on narrowing this a bit with some wood so the gap is about 5mm, then doing the backer rod and caulk as usual.

Cheers,
Jennifer

#6

Greetings Jennifer,

Full marks to Stuart for giving you the COMPLETE explanation! I think that after fitting those three heavy doors, I just put the details out of my mind. It was

backbreaking yet satisfying work

to quote you directly.

So I put shims at least where the hinges will be, and where the latch will be, and at the top and bottom of the side frames, and anywhere else that will fit. Then seal. Wherever an anchor screw goes through, there is also shim behind that. In other words, each anchor screw goes through a shim.

I know Stuart might disagree, but I would stress the above as the most important detail he wrote.

Whaaa??? There's no header (lintel) above the door????

Reminds me of Faulty Towers (the "Mr. O'Reilly" episode which contains one of my favorite exchanges of dialogue:

O'Reilly: If the good Lord...

Faulty (cutting him off abruptly): ...is mentioned one more time, I shall move you closer to Him.)

All the best,

Paul

#7

SoWhat wrote:Source of the post
backbreaking yet satisfying work

Describes so much of this studio building work!

Reminds me of Faulty Towers (the "Mr. O'Reilly" episode which contains one of my favorite exchanges of dialogue:

O'Reilly: If the good Lord...

Faulty (cutting him off abruptly): ...is mentioned one more time, I shall move you closer to Him.)

We've just bought the whole series on DVD, I will enjoy waiting for that that moment. The episode where Basil is trying to hang a picture is one of my favourites.

Cheers,
Jennifer

#8

Just a wee update - I finished putting that door back together at the start of the week. Packing at all the screws and some additional points, and sealant to the max. I also improved the "threshold" where the drop seal meets the floor. It feels sturdier when closing, like that luxury car door thing. Certainly a big difference compared to the same type of door across the landing. Subjectively I think the isolation has improved, if there is ever time I'll do some measures :-)

Thanks again for the help folks.
Cheers,
Jennifer

#9

Greetings Jennifer,

Congratulations on the door project.

Are you going to attach a closer? (Or maybe you mentioned it somewhere and I missed it...)

All the best,

Paul

#10

Thanks Paul. Next job is to do the same to the door across the landing :-)

There already is a door closer of the simple concealed type. It's completely integrated into the door and frame, just below the middle hinge. Believe it or not, it generates sufficient force to close the door automatically even with the drop seal fitted. The door is fire rated to FD30 and has mass ~45kg giving 27kg/m2 surface density.

Eventually I plan to add one of these proper above the door ones. That's a while away though, and is part of project "beef up that entire wall", which will include yet more beefing of the door :-)

Cheers!
Jennifer

#11

That is good news on your door and useful advice from Paul and Stuart.

endorka wrote:Source of the post In the UK the caulk should be intumescent stuff as it's a fire door.

I had to look up intumescent. Intumescence is an interesting topic for studio building where not everything is fire-rated. I like the idea of intumescent paint and wood varnish, especially the latter.

Thanks for that, Jennifer.

#12

You are welcome, it's pretty clever stuff. I first came across it on the fire doors in our house, which have a strip of it all along the perimeter.

By way of update, I've now improved the door to room 2 in the same way. Much faster to do now I know how it's done, but still quite hard work! Thanks again for all the help folks.

Cheers!
Jennifer

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