Door Jamb Question

[Tom Winship]

I have a friend who is building a storage shed and he asked me how much larger than the door should he make the door jamb?
I would guess 1/16" on each side or 1/8" total. What do you guys think?

[Chris Harry]

Ive always done 1/8" on each side. It will allow for out of plumbness a little better, plus you also need to take into account the expansion and contraction of the door material.

[Brice Burrell]

Ive always done 1/8" on each side. It will allow for out of plumbness a little better, plus you also need to take into account the expansion and contraction of the door material.

I'll second this. I'm a remodeling contractor and I've installed a ton of doors, 3/32"-1/8" per side is normal. With a shed that will be outside and likely be low to the ground where it could be exposed to more moisture, I'd go with 1/8" on each side.

[Tom Winship]

Thanks guys. That's what I like about SMC. Instant advise from those who have experience.

[scott vroom]

1/8" on each side is cutting it too close unless your rough opening is near perfect to square/level. My advice is to make the outside jamb width at least 1/2" narower than the RO. This will allow for adjustments to square/level. Your jamb must be level to gravity to avoid the door from swinging either opened or closed on it's own.

[Peter Quinn]

A standard gap on passage and entry doors is 1/8" in my area. That is the gap between the door and the jamb legs/head. The bottom gap depends on the type of weather seal used, if any on a shed door. The rough opening would be the door width+2X the gap+2X jamb thickness +(1/2"-1"), or at least 1/4" and as much as 1/2" shim space per side For an unheated outdoor stucture, ou mainly need to keep the animals and rain out, so these rules can be relaxed a bit.

[Mark Woodmark]

I have a friend who is building a storage shed and he asked me how much larger than the door should he make the door jamb?
I would guess 1/16" on each side or 1/8" total. What do you guys think?

I would go with a prehung door, much easier to install. Rough opening approximately 1/2 to 1 inch wider and 1/4 to 1/2 inch taller than outside of jamb

[Neal Clayton]

agree on the 1/8, it's what i've always used.

for an exterior door the thicker you can make the frame the better, too. 1.5" overall thickness with a 1/2" high jamb is a good place to start.

[Myk Rian]

1/8" on each side is cutting it too close unless your rough opening is near perfect to square/level. My advice is to make the outside jamb width at least 1/2" narower than the RO. This will allow for adjustments to square/level. Your jamb must be level to gravity to avoid the door from swinging either opened or closed on it's own.
He is asking about door to jamb, not jamb to opening.

[scott vroom]

Myk, thanks for correcting me. You're right, I was talking about jamb OD vs rough opening.

I agree with the poster that suggested buying a pre-hung door....so much easier than trying to hang your own. Just give your door shop the rough opening and they'll size the jamb (usually 1/2 to 1" smaller than RO width). Remember to factor any planned floor build up so they can get the height right (e.g., carpet, wood flooring to be added later?)