Installing pre-fab door

HI All,

Our house has a dodgy extension which is poorly insulated and unheated. Our "mud room" off our kitchen gets freezing in winter and makes out kitchen freezing too. I'd like to install a door here. There's actually already a jam here for what would have been the back door long ago. However the hinges for this jam open inwards and placing a door here would reduce the space of our kitchen (we'd need to move our breakfast table).

Hence i'd like to put a door in that opens outwards, hinges on the right. I could put an internal door here but there's only 1" of space on the other side of the jam.

It seems like it might be easier to rip out all the framing there and install a new exterior door and jam which you can buy pre-fab from the big orange hardware store.

The opening for the framework is 3' x 81.5" (WxH), the hardware store said the jam of the exterior door needs 33.5 x 81.5". Seems i'm a little tight on the height and too wide on the width.

Does anyone know of some online instructions for installing a pre-fab frame?

From what i can see i would need to do the following

1) rip out jam and framework, exposing a brick outer i guess?
2) install 1 1/4" frame on sides to reduce width of opening to 33.5"
3) slide in frame and level and screw to frame in (2)
4) create joinery to fill in gap above door (arc)
5) seal all gaps around door with sprayfoam

I guess my questions on this are

a) do i install the pre-fab jam on the concrete step i have (see pic), one instruction set i saw said to put blocks under the jam. But my door will swing well above the lower mud room.
b) how do i attach what ever frame work i create in (2) to what i assume will be brickwork? Blue masonry screws?

cheers

oman

 

I guess a lot depends on how hard or how easy you want to make this on yourself. Its hard for me to say "exactly" what to do, since so much of it depends on what you find as you tear into this to do it. But...

My initial thought is that based on the bottom picture, you may not want to remove your old jamb, since it looks like the trim on the exterior side of that doorway goes behind the mudroom wall (brick?) Does it look like that on both sides? If so, what is the distance between the brick out there? And what is the height of the masonry opening out in the mudroom?

What I'm thinking is that you should remove the interior casing. Use a sawzall to remove the top part of the jamb, because I think you may need the height in order to get a new exterior door to fit. Most exterior doors will be about 82" tall- tip to tip- before trim. If the width between the existing jambs is 36" then I would suggest you get a 32" outswinging prehung door. (outswinging may be special order, but IMO that's what you should have there. It will have a longer sill on the inside... the door will be set to the outside, and it will have a small sill nose on the outside of the door.) This will be better than just getting a standard inswing door that you install as an outswinging door because there won't be any sort of sill on the exterior, so when you open the door it will seem like a big "step" over the threshold, which will be about 1 1/4 - 1 1/2" tall. Try and get a door with an adjustable threshold. Most- but not all- will come with it standard.

A 32" door will measure 33 1/2" and will require a 34 1/2" rough opening... not 33 1/2". So if the opening is 36" wide now, just add a 1x4 or 1x6 onto each side to make it 34 1/2", and screw or nail it to the existing jamb. Measure your wall thickness (the width of the jamb in your bottom picture) and order the door that exact thickness. 4 9/16" is standard. Yours may be different. I'd order it so that it comes exactly the width that it needs to be so that you don't have to do a thing to make it work.

After the door is set in the opening you will need to make sure it is plumb, level and square. If the concrete sill is already level, that part will be easy. If the concrete is not level you will want to shim the sill to make it level before you set the door in the opening. You will then set the door in a heavy bead of sealant. Make sure you caulk where the bottom of the door is solid, not where it's hollow. With the door still closed, take a few shims and cut them so they are about 1/8" thick. Stick them between the door and the jamb at each corner of the door to make sure you have that 1/8" gap at all corners of the door. (this is a little trick that helps speed the process and makes it almost foolproof). Then shim the door frame within the rough opening by shimming around the OUTSIDE of the door jamb with tapered cedar shims. Use shims in pairs that face in opposite directions so that if you slide them one on the other they will get thicker or thinner, depending on how far you slide them. Center the sill in the opening by measuring to the brick on each side. Then shim the door frame on bottom so it's snug and can't move left or right within the opening. Then put your level on the hinges, and plumb the door. (78" level works best for this, so you check all 3 hinges at once) Then repeat the shimming process and plumb the door, shimming the top of the door so that it can't move right or left. These shims should all be directly behind the hinges and across from the hinges, by the way.

You will want to put a few finish (casing) nails or trim head screws through the door jamb (right through the shims is best) and into the rough opening to hold the door in place. At this point you should be able to open the door and check it's operation. When you close the door and it is 1/8" from closing, check the gap while the door is close to the jamb- this gap should be straight. If it isn't the door isn't perfectly plumb... or the wall isn't plumb, or maybe some of both. Moving the door in or out will straighten that gap out so that it contacts the weatherstrip evenly.

You would then add additional shims and nails/screws as needed around the perimeter of the frame to complete the installation, using the 78" level on the sides as a straight edge to make sure you aren't bowing the frame in or out. Add a 3" long screw to each of the hinges to be sure the weight of the door never causes those hinges to sag.

Then you'd insulate (be careful with the spray foam not to overfill it!) and install your doorknob and deadbolt. The door can then be trimmed inside and out with your choice of trim. A flat casing (1x4) would probably be best since it may need to be ripped to a custom width inside and out.

I probably said more than you hoped for and you may have additional questions, so ask away, we're happy to help.

 

Does the new door need to be an exterior door?

You should be able to fit a pre-hung interior door into that opening with some fill-in along the sides (this may require some additional drywall/taping to match the existing interior wall. This might simplify a few things since the original jamb being for an exterior door likely means that the "stop" part of the jamb is solid to the main board rather than possibly being a nailed-on piece of trim, so filling in some space would eliminate the need to either trim off or remove the sides of the jamb (the top of the existing jamb may still need to be removed depending on the height of the pre-hung unit going in).

 

Thanks for the detailed reply XSleeper , bmgreene

I am considering a interior door, one issue is that the exterior side of the trim is only 1" wide for hinges. Possibly enough but not really. The off the shelf doors seem to be 1.5".

Another consideration is that we plan to gut this kitchen and probably the mud room in the future so i don't want to spend too much cash on this, hence the off the shelf door options. However i want my house to be comfortable for the next few years so hence the exterior door.

I ripped off the interior trim to get a better idea of the frame work. I've included some pictures to clarify some of the questions.

With the trim off you see mainly new framework (pic 1). If you look closely on the right hand side you can see what was possibly the original framework (1920-1950) (pic 2). On the top left hand corner of the removed trim you can see behind the new framework is the brickwork, no sign of old framework (pic 3). The mud room side of the framework. The exterior mud room side has some "decorative trim which butts up against the main jam. It appears the new jam is a rectangular block with a step take out of it for the door. The "decorative" trim then butts up against this on the exterior mud room side.

The width of this exterior "decorative" trim is 35" where as the interior new framework/jam is 34.5" wide. If you include that old framework barely visible in pic 2 then this makes up the 0.5". So it appears that "decorative" trim is just hiding the old framework.

The framework is poorly insulated, with the trim off i feel a breeze coming from the brick work side. My double bricks are full of drafts within the cavity.

One thing i've just noticed is that the new framework goes below the concrete step so removing it might not be neat (i guess i'd just cut it flush with the step).

I guess i'll look into a custom door to fit the framework but if the price is prohibitive i may just go with an interior door to fit the existing jam.

cheers
oman

 

Using the existing jamb looks like it would require the door to be swung into the kitchen since it looks like there's a rabbeted stop on that side of the jamb. Swinging a door the other way at that size will almost definitely require you to remove and replace the entire existing jamb.

With the existing jamb being 34.5" wide, you could frame in some additional 2x4s inside of that jamb and make a new "rough opening" that should still be wide enough to accommodate installation on a pre-hung 30" interior door set to swing the way you want it, you'd need to patch in something to fill the wall surface between the old jamb and the new opening, strips of sanded plywood would probably work well enough for a few years once it's all taped, mudded and painted over. You'd likely have to remove the upper portion of the existing jamb, which would make it easier to remove the rest of the original jamb if you wanted to; not strictly necessary since you'll cover over them when framing in a smaller opening, although removing the existing jamb on the side that's on the right in the first picture would allow you to set the new opening a bit closer to the back wall and would mean you'd only need one board to re-frame for the smaller door.

A cheaper and simpler solution, if you can live with the appearance until you get to gutting the room would be to replace the casing (you could fill some of those gaps with canned foam insulation if you want, although the casing will cover them anyway), and put in an accordion door. I've never seen one that looked particularly good, but it'd keep the cold air in the mud room and out of the kitchen fairly well without the need to modify the framing or fill gaps in the walls, and when you gut the whole room in the future you can re-frame and replace that with a proper door as part of that project.

 

I'd still steer you in the direction of leaving that old jamb in place and use it to attach your new door.

If you are going for an interior door, a 32" door would easily fit inside your 34 1/2" opening since it will be 33 1/2" wide... with no additional framing needed at all. (assuming you are saying 34 1/2" is the width between the jambs...) Once it's shimmed in place inside the existing jamb, use foam to insulate the perimeter if you want to stop the drafts around the edges. Same goes for the gaps around the original jamb. (DAP latex foam will probably be less messy) But an interior door isn't going to be real tight... no weatherstrip (unless you add some) and a big gap underneath (unless you add some sort of sweep).

 

Thanks again for the input guys,

i think i've lead you both astray however, when i said the existing jam was 34.5" wide i meant the outside dimension of the jam if i were to rip it out. The interior of the jam is 32".

Given the potential difficulty in removing the jam i think i'll just to the logical thing and put an interior jam on the inside of the kitchen using the old hinge placements. It won't be what i want but it will get me through the next few years.

I did wonder if i could get a exterior door on its own to fit this 32" wide jam (without the pre-hung frame).

cheers
oman

 

If it's 32", then a 30" interior prehung door (31 1/2" wide) would fit inside your existing frame, like bmgreene said.

I wouldn't suggest you try to hang a door on your existing frame. But whatever.