wilkes

i forgot the clearance for the door is in the door it's self ,,the door will measure 1/4 inch shorter ,,, a 36 " door will measure 35 3/4

Hello,

You have to decide whether your replacing just the door or the whole frame. If you want to do the whole thing, you'll be buying what is called a pre-hung door. I would advise cutting the sheetrock a few inches wide around the whole door and removing it, and then getting your "rough" measurement from stud to stud (most likely 2x4") and top to bottom. From that point bring your rough measurements to your local home improvement store and they should be able to help you quite easily. Pending on how old your house is they can be quite a pain to install. Make sure you buy a little pack of shims to help with the install. 95% of the time, they will be used. Definitely have a 2 and 4 foot level handy and check your level and plumb. If it's your first time, don't get upset if you have to pull it out and start over again. You'll be alright. Feel free to e-mail anytime with questions. Thanks, and good luck.
Ryan

Oh, if you buy the slabs you have to mortise out for the hinges too. This is already done on the prehungs.

they are pretty much standerd sizes 24"28"30"32"34"36" just measure the width of the door

Are you gonna just put in new door slabs in existing casings? Or tear out the casings and put in prehung interior doors?

If you're just going to put in door slabs, measure the existing opening or the existing door and get a size that fits. You might have to plane down the new door so it won't rub. Bear in mind that door casings in old houses can shift quite a bit, so the gap at the top ends up being crooked, unless you plane the new door crooked to match. Have to buy new hinges to match the existing hinge cutouts, unless you use the old hinges. You have to bore out the door slab to install the knob.

The prehung interior doors with the clamshell casings are pretty easy to install. They are already bored for the door knob, too. But the 2 1/4" trim molding probably won't match the rest of the house. You have to tear out the old casings to mount these; not difficult.

They very well could be of a different size.Get the mesurements for the width and heigth.

ok thanks, I live in a very very old house these doors frames look twice the size as a reg. one

measure the inside opening where the door will fit, give that measurement to the supplier, they will know how to give you what you need. It should be a standard size

I AM NEEDING SOME DOORS FOR THE INSIDE OF MY HOUSE HOW DO I MEASURE THE FRAME TO KNOW WHAT SIZE DOOR I NEED ???