Learning how-to doors!

Old door was inswing that had exterior brickmould built in. New door is an outswing that does not have this feature.

How can I add brickmould to this fiberglass door as it sits, in order to close the gap between where the door (which is flush to the rough) meets the siding (which sticks out a bit)?

Siding is vinyl, here are some additional photos to give a clearer picture of the situation: https://imgur.com/gallery/DjK1rqg

Essentially the old door was an inswing that had exterior brickmoulding integrated and it sat proud of the rough, where the new door did not come with brickmoulding and sits flush with the rough opening/backer foam.

Much love to everyone reaching out to lend a hand. I really appreciate yall's time and knowledge.

Or has a blunder been made?

enter image description here

  • How is the door located? New door looks smaller than old one. I suspect that the proper thing to do is to remove the surrounding siding and fill the gaps, then re-J-channel around it (can probably reuse existing). You might be able to just shift the siding on the left of the door, but the top and right side you may need new siding, since the old will be too short.
    – Huesmann
    Commented Jul 12, 2023 at 12:35
  • @Huesmann Some add'll photos for clarification imgur.com/gallery/DjK1rqg. The old door was an inswing that had exterior brickmould integrated, this door doesn't have that so it ended up sitting flush with the foam backer board/the rough opening. Trying to close the rough gap, maintain water barrier and hopefully rework as little of the vinyl as possible, though I'm not against that if nessesary.
    – David
    Commented Jul 12, 2023 at 15:30

1 Answer 1


You basically have two options:

  • Rip down your brick mold to fit the gap you have. Take some measurements, arrive at an average for each segment, and run it through a table saw. Vinyl is flexible enough that you can size for the wider measurements. Steel isn't.

  • Redo the siding to fit the brick mold. Obviously this is more complicated, but you'll have standard brick mold when you're done.

Be sure that what you install doesn't impede door swing. You may want to use 1/2" or 3/4" flat stock rather than actual brick mold, which is rather deep. Another advantage of that is that the cut edge wouldn't show like it would with ripped brick mold. I'd probably go that route.

Brick mold has little to do with the water envelope in a maintenance-free scenario. That happens, with vinyl siding in particular, at the house wrap and any tape flashing. You should install adhesive flashing tape over the gap first, after any insulation is added from the outside. The brick mold would primarily (and maybe only) attach to the door jamb. I'd consider using trim-head screws for best hold, but casing nails would also work.


  wall sheathing   | % |      | <-- door jamb & insulation (%)
___________________| % |______|
----------------------------    <-- house wrap and flashing tape
        J-channel  ||________|  <-- brick mold or flat stock trim
             ______|       ^------- fastener location 

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