Metal door knock down frame versus welded

[branimal]

I'm installing a metal 36" x 96" 90-min fireproof door for an interior apartment entrance door.

My wall thickness is 4 7/8. 3 5/8" metal stud plus 5/8" drywall on each side.

The door wall is being framed today. The space I'm working with is 48 1/8" wide.

While shopping for doors I've found both knock down frames and welded. Cost is roughly the same. There is a difference in rough opening though.

For welded frames you add 4" to the door width. K/D frames you add 2".

I have enough space for either type of door. I'm trying to figure out how I can slip pieces sheetrock behind the metal door jambs given my tight configuration. I think you need to slip pieces of sheetrock behind with a welded frame. And with a K/D frame the sheetrock is already up. Not sure though.

Does my wall spacing limit me to just a Knock Down frame?

 

[readhead]

I would prefer a welded frame in a perfect world. Is the floor perfectly level? Sometimes the framers aren’t very careful setting the frame. If you don’t mind the exposed fasteners you may have more control with a KD frame. Plus you won’t have to protect it during construction. Does the frame have to be grouted for the rating?

 

[spike99250]

A welded frame should be in before the framing, the bottom track is usually run, door frame set then framing around and attached to door frame.

You can set them after but it is a pain, unless they leave out the top framing and don't screw the top of the trimmer studs.

 

[The Cobbler]

my experience is the welded frames are more rigid . there are different mountings available for welded too. some have metal flaps that screw to the studs , top, middle & bottom, others have holes thru the jamb to fasten to the framing etc. usually the drywall would be butted up to the "casings" of the frame with j-channel
the KD frames can have a cleaner, more residential look in that the frame slips over the drywall .
be sure the frame is fire rated too.

 

[MikeinNorthWales]

For fire-rated, the drywall must go 1" behind the frame, not butted against.

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[branimal]

Sorry for the late response.

@readhead The floor in the opening is pretty close to level. +- 1/8"

Using a welded frame: My issue is going to be slipping sheetrock into the inside corners in my door opening area.

If I space the door centered in the opening, I'm going to have 2 inaccessible inside corners. Marked 1 & 2 on the first diagram.

I could push the door frame all the way against the hinge side wall, which I believe will eliminate the need for sheetrock on that side. Can I **** the door frame onto a wall? See the second diagram. Is butting the door against a wall going to cause some other issues?


Knock down Frame: Eliminates the issues listed above. I just need to create the rough opening. Drywall. Install the door after painting is complete.

 

[kbs2244]

In the end this is going to be a fire code issue.
Check with who ever is going to inspect it before you do anything.

 

[peezer]

With the layout you have you will be better off with the KD frame. You will have to stub out the wall on the hinge side so the compression anchors have something to press against a the top, and bottom of the frame has something to tie into. I would go ahead and build the wall with equal spacing so the two walls are connected, sheetrock it, and throw the frame in the wall. Make sure to put the connecting screws through the head on the frame into the legs (most frame manufactures dont supply these with the frame).