Door for staggered 2x6 stud construction

bigerock · Post by **bigerock** » Sat Jul 23, 2005 4:02 am

I need help as I'm wanting to install the door tomorrow!

Does anyone know how to install a pre-hung door in a staggered stud construction?

Staggered stud meaning I've got 2x6s as the base and 2x4s staggered 12" oc in order to decouple the 2 walls (inside and out).

Problem is, when you go to install the door, you can't really install it on one of the staggered studs sided because you would short out the walls by having the wall that you're not installing the door on touch the drywall.

For example, let's say I install the door on the exterior studs. Well, since the door is only made for 2x4s, you're gonna have a space on the other side of the door (the rest of the 2x6).

Anyone understand what I'm talking about? Sorry if I'm being cryptic.

Thanks so much.
I really need the help!!!

Deluks · Post by **Deluks** » Sat Jul 23, 2005 4:43 am

Slightly confusing question there, this will probably be a slightly confusing answer cos I smell my dinner!

If you are using double walls then you really want double doors, otherwise that single door had better be damn heavy!

If you are using 4x2 to hang the door from then it shouldn't reach the other wall should it? There will be a 2" gap (the rest of the 2x6).

That gap should be filled with fabric covered insulation.

If using 2 doors, cut a 2" square from the bottom corner of the door frame and sit it on the base but protruding out by 2", then hang the door from it flush with the wall. Do the same for the other side and there will still be a 2" gap between each door frame, again should be lined with insulation.)

I'll elaborate later, hmmm curry!

bigerock · Post by **bigerock** » Sat Jul 23, 2005 4:53 am

Deluks wrote:If you are using double walls then you really want double doors, otherwise that single door had better be damn heavy!

I'm not using double walls. I'm using 2x4s staggered on top of a 2x6 base.

Deluks wrote:If using 2 doors, cut a 2" square from the bottom corner of the door frame and sit it on the base but protruding out by 2", then hang the door from it flush with the wall. Do the same for the other side and there will still be a 2" gap between each door frame, again should be lined with insulation.)

Sorry, I'm not too clear on this one. So, you're saying to hang 2 doors, I should have both doors protrude a bit from the base?

Also, I've read the following post on installing a hollow-core door, reenforced by MDF and veneer. This is something like what I wanted to do, however, I was unclear on how to do this on a 2x6-base, staggered stud wall.

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=1662

Perhaps I should pose that question on that topic as well.

Thanks.

Dan Fitzpatrick · Post by **Dan Fitzpatrick** » Sat Jul 23, 2005 5:03 am

if i understand this right i think you will either need two doors, OR you will have to run a 2x6 all around your door frame, which will couple the two leaves at the door.

there is no way to maintain decoupling at the door without two doors. assuming your door is in the outer leaf, if you cover the gap with cloth, you will have a gap in your inner leaf at the door -- you might as well not have the inner leaf at all.

keep this in mind. your inner and outer leaves are already coupled at the top and bottom with a staggered stud wall. so, should you couple them at the door as well it wont' make things much worse.

but you really should avoid this by using 2 doors. there is really no point in having a staggerd stud wall if you are using one door, IMO. the door will be a big weak point probably.

bigerock · Post by **bigerock** » Sat Jul 23, 2005 5:28 am

just to make things easier, i'm posting a diagram...

the problem is, the interior side right now. should i somehow put another door there? or should i find a way to pad the hole left with material (as was mentioned)?

thanks very much!!

Dan Fitzpatrick · Post by **Dan Fitzpatrick** » Sat Jul 23, 2005 5:44 am

bigerock,

you have to make it so the sound HAS to travel through BOTH LEAVES to get to outside. in your diagram, sound can go through the gap around your doorway and go throught the outside leaf only. again, as it stands now your inner leaf is almost useless.

so ... you need to put another door in your inside leaf (preferably without coupling your doorframes) OR you can fill in the gap solidly with another 2x4 and make the space between your leaves AIRTIGHT (not so good, but better than what you have).

either way the space between your leaves has to be airtight to the inside and outside.

if you do a second door, you obviously have to add studs on the interior side to hang the second door on. trouble is you only have a 2" space to work with ...

maybe you will have to have the second door stick out a bit from the wall into the interior

also if you are using 2 doors to not use the hollow door method, use solid doors. (2 leaves)

and i have to emphasise that having good seals around the doors all the way around including the BOTTOM is a must.

make sense?

dan

bigerock · Post by **bigerock** » Sat Jul 23, 2005 5:54 am

dan,

is what you're suggesting something like this ??

is this going to be stable enough? because the 2x4 studs are going to only be half-way on the 2x6. Effectively making it a 2x2, sort of.

Post by **sharward** » Sat Jul 23, 2005 6:17 am

How about using a prehung door with a 2x6 frame, and then adding a door (not prehung) to the frame on the other side? They would share the same doorstop. You'd probably have to use low profile hardware (door knobs) so that they wouldn't come into contact with the opposing door. In fact, one or two self-closing hinges on each door may do the trick and might eliminate the need for any hardware at all (be sure to do a good job filling the hardware holes with something dense and heavy, like drywall mud maybe?). That way, "pull" handles would be all you'd need.

I agree that by using a 2x6 frame you will essentially be coupling the leaves together at the edges of the door. The same is true with corners, tops, and bottoms though. That's one of the disadvantages of staggered stud construction.

The small gair gap you get when hanging two doors on one frame is going to hurt isolation... But leaving a huge hole interior leaf for sound to bypass the interior leaf altogether would hurt even more.

Dan Fitzpatrick · Post by **Dan Fitzpatrick** » Sat Jul 23, 2005 6:39 am

bigerock wrote:dan,

is what you're suggesting something like this ??

is this going to be stable enough? because the 2x4 studs are going to only be half-way on the 2x6. Effectively making it a 2x2, sort of.

that's exactly what i meant

the double stud frames you show in your drawing only need to be about 1 inch apart. but you are right the studs will overhang your bottom plate. maybe you can extend the plate a bit to add stability?

reinforce the connection of the doorway stud to the ceiling framing too if needed.

sharward wrote:The small air gap you get when hanging two doors on one frame is going to hurt isolation...

just to clarify, i'm sure what keith means is that the small depth of the gap is the problem, not the existence of the gap ... the gap itself is a good thing, and bigger is always better (sorry to butt in keith

)

bigerock · Post by **bigerock** » Sat Jul 23, 2005 10:44 am

well, i'm still confused about what to do.

does anyone have any idea which idea is best for STC?

the choices are

1) (my drawing) two pre-hung doors spaced out one inch apart, which essentially decouples them from their opposing walls, but makes them stick out of the frame quite a bit

or

2) (sharward's drawing) one pre-hung door with one non-pre-hung door attached to the opposing side of the pre-hung. this doesn't decouple from the opposing walls, but does allow the door to be hung in-frame, and does produce an air gap between 2 doors.

VOTES?

please! i need your help because i'd like to do this door project this weekend.

thanks again!!!

Dan Fitzpatrick · Post by **Dan Fitzpatrick** » Sat Jul 23, 2005 3:12 pm

bigerock,

the option where the two doors are decoupled (your drawing) will provide better stc for that doorway.

in addition the benefit of decoupling your two doors, you will most likely also end up with a larger air gap between the doors, which will be better.

considering that the door is usually a weak spot in any isolation effort, i think it would be advisable to do the best job possible here. that means as much decoupling as possible.

also, at some point you should attach several inches of insulation to the inside of each door.

good luck this weekend! take pictures!

dan

bigerock · Post by **bigerock** » Sun Jul 24, 2005 12:27 am

thanks so much for your help everyone. and especially dan.

i will go buy that other door this morning.

i'll let you know how it turns out!

- eric

Deluks · Post by **Deluks** » Mon Jul 25, 2005 4:06 am

bigerock wrote:well, i'm still confused about what to do.

does anyone have any idea which idea is best for STC?

the choices are

1) (my drawing) two pre-hung doors spaced out one inch apart, which essentially decouples them from their opposing walls, but makes them stick out of the frame quite a bit

thanks again!!!

That's what I meant. The frame may stick out, but the doors could still be flush with the wall, although sticking the doors on the outer edge of the frame would give an increased airgap between doors, which is good in isolation terms.

You just need the frame to be a certain size for strength. Less than a2x4 could be 'wobbly'

Just rebate the door frame where it sits on the stud plate, so the 'sticking out' bit sits flush with the floor.

You may want to use extra studs either sides of the frame, for support.

Good Luck!

bigerock · Post by **bigerock** » Mon Jul 25, 2005 10:41 am

ok, well, i only got one door up this weekend.

however, as promised here's some pics of my progress.

as you can see, i haven't put up the headers yet, but it's getting there.