We recently replace some bad trims and changed some windows. But we ran into this issue now where the siding is not touching the new trims.

Some part is is just 1/4" but this photo shows the largest gap is 1"

What is the best way to deal with this?

I am thinking of some options:

Option 1: Cut another piece of trim 1". Set the depth of the skilsaw and cut siding back evenly. Then insert new trim to fill the gap.

Option 2: Fill with caulk and paint.

Option 3: Fill with foam and paint.

Option 4: Nothing we can do. Just paint and leave it alone.

Option 5: Replace all sidings and make them 1/4" to 1" longer. This is a very expensive solution.


  • 3
    Is there some reason why you can't pull that trim piece off and replace it with a wider one that closes the gap? That's a very wide gap to fill with caulk or foam and I believe it will not stay put for long.
    – jwh20
    Commented Jan 27, 2020 at 12:31
  • Is your goal to make it look good or just prevent water from causing further damage? If you want it to look good then remove that trim and replace it with trim that's actually wide enough. I also recommend using a single piece that's long enough for the run instead of joining scraps like you show in the picture. If you just want to prevent water issues then smear caulk/silicone inside that gap or spray with FlexSeal. If you attempt to fill the void completely with caulk then that sounds expensive. You can try spray foaming but then you'll have to shave it to match the profile of your siding.
    – MonkeyZeus
    Commented Jan 27, 2020 at 14:35
  • Just a curious question, was the original corner board tapered so the gap was filled? Or was something added at the corner plumb, and the original siding moved out of plumb over time, creating the taper?
    – Jack
    Commented Jan 27, 2020 at 15:24
  • @jwh20 Replace a wider trim piece is an option. I just had to run to the store and buy a new one. But I forgot to measure how wide it is (my fault).
    – HP.
    Commented Jan 28, 2020 at 1:41

1 Answer 1


Your best option is cutting back the siding so the corner board, whether you add a piece or remove and rip a piece of 5/4X6 to fit the new width.

If you choose to add a piece after cutting the siding, the gap looks like it may only need a piece of 3/4" material in the gap which will leave a small caulk gap to fill. Another suggestion I would like to make is, do not try to line the face of the added piece to match the board in place as in trying to make it look like one piece, it will not work. The caulk at that joint will smear over the face and change the texture of the corner board, just like the joint in the picture, where I would take a hand wire brush to, and texture that joint by pulling down only on the brush to remove some of the filler, leaving hopefully coarse lines to help blend the joint in. Since the joint is cut at an angle it will shed water, if the cut ends are primed, better still. Square cut butt joints will allow water to easily migrate in, but you do not have that here. So much for the side note.

The idea is to either recess the added piece to create a 1/4" reveal to the corner board there now, and still have the bevel siding a little behind the added piece still. That way the inside corners can be caulked easily without smearing all over the face of the trim.

If that won't work, do the opposite add a piece that is 1/4" thicker than the corner board to create a reveal over the existing corner board, giving the needed corner to caulk to.

Over all the best thing to do is to cut the siding and replace the corner boards ripped to meet the newly recut siding. Either way you go, bed the corner boards in caulk after any cut ends are primed. Not so much to make it ooze out all over, but enough to know the caulk is working "behind the scenes" and finish up the faces with caulk for painting.

Please realize, caulk can hold in water as well as keep it out, so be certain all caulk is filling what it needs to fill. Surface caulk will fail over time, the stuff you place behind your material is protected from UV and weather so it will outlast anything on the surface.

  • Good advice, I would make it uniform, it is amazing how small even an untrained eye can see , they might not know exactly what is wrong but see it if not uniform. I wonder if the new or old windows were not plumb.
    – Ed Beal
    Commented Jan 27, 2020 at 16:12
  • @Jack Thanks for the details with a lot of information that I still have to digest. Just want to clarify the "1/4" reveal" and "1/4" thicker" idea. So the current corner board now is 1" thick. Do you mean to add another one next to it but instead of 1", do either 3/4" or 1 1/4"?
    – HP.
    Commented Jan 28, 2020 at 1:57
  • Precisely, depending how the thickest part of the siding meets a filler 3/4" thick. If you siding is 1/2" thick, laying over the lower course, it should be no thicker than 5/8"-3/4" thick total, so the siding would only flush up to the filler and not project past the corner board filler. That would be the way I would suggest to go. If the original corner board was 3/4" it would have been a 1" filler to get the reveals past the corner and the siding. A 1/2" filler would not have worked against the siding.
    – Jack
    Commented Jan 28, 2020 at 4:14

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