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Replacing exterior door....vinyl siding troubles

Replacing exterior door....vinyl siding troubles

Old 08-30-15, 11:12 AM
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Replacing exterior door....vinyl siding troubles

I'm in the process of replacing an exterior door on my detached garage. I purchased a JWeld pre-hung left-swing door.

The problem, is that now that I've ripped out the old door; I see that the vinyl siding overlaps the rough opening all the way around about an inch. Below is a picture of a top corner. It also had J-Channel going around it. The siding it interfering with the trim on the outside of the new door.

Should I trim the vinyl siding back so that its flush with the rough opening? Or should I remove the outer trim from the door and just let the siding and J-Channel serve as the trim?

The reason the door needed to be replaced is because the jam on the old door was rotting at the bottom. The old door had the threshhold removed, I think because it will overhang the concrete floor but I think I'm going to keep the thresshold and just use some bricks or pavers to "extend" the concrete floor under the thresshold.

Any suggestions would be greatly appreciated!

Its a 34 1/2" rough opening.

Thank you!!

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Old 08-30-15, 11:33 AM
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Well, normally you would remove all the siding, install the door and door trim (brickmould), then nail the j-channel on, and reinstall the siding.

However you could take a shortcut. I assume your door has brickmould already installed on it? (or does it have a nailing fin?) If it has brickmould, I would carefully remove the brickmould (save it so you can put it back on later) and then install the door, making sure you shim the door to the rough opening and get it plumb, level and square. Use long trim screws through the jamb and shims... to attach the door to the rough opening.

Once the door jamb is installed and the door operates properly, you will then know exactly where the outside edge of the brickmould would be. Brickmould is 2" wide... and it's set back 1/2" from the inside edge of the door jamb. And vinyl siding needs about 1/4" of room inside the j-channel for expansion. So if you hook your tape measure on the inside edge of the door jamb, and measure out 2 3/4" and make a mark, that would represent where I would suggest you cut the siding. Fastest way to cut it is with a 4 1/2" grinder and a 1/16" abrasive wheel.

Once the siding is cut back, you can slip your j-channel onto/behind the siding. You would also normally want to slide a drip cap (z-flashing) behind the top j-channel at this time. Now nothing will be holding any of the j-channel... so to hold it in place, you next install the brickmould, and fasten it to the door jamb and to the sheathing. Once the brickmould is installed, a few stainless steel #8 x 3/4 screws can be used to fasten the j-channel to the sides of the brickmould.

Another way of doing this would be to measure your top brickmould... I assume with that size of rough opening its a 32" door and the top brickmould would be 36" long. Find the center of your rough opening... then measure about 18 1/4" each direction from that centerline and mark the vinyl siding. Plumb that line down to the bottom and cut that siding off. Then slip the j-channel in... then install the door (without taking off the brickmould)... then once the door is secured, screw the j-channel to the brickmould.

That's the general idea anyway.
Old 08-30-15, 12:58 PM
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Siding should have been removed before the door was removed.
Just going to make it far harder on yourself trying to do it as Xsleeper suggested.
Adding a simple strip of 1X PVC lumber under the threshold and Tap-Conning it to the slab will support the threshold and never rot or need painting.
Look or feel under the outside part of the threshold, there's a 3/4" slot for it to slid up into.
Never ever use anything that sticks out beyond the threshold! If you do waters going to get in under it.

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