Said It Here

How to fix gaps under door jambs after new flooring

Removing old flooring or changing plank thickness often leaves exposed gaps and subfloors under door frames that are difficult to make look right without experience. Depending on the size of the gap, homeowners can either fill them using wood filler or Bondo, or glue in custom-carved wood inserts before painting or staining.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Leaving the gaps alone and living with them
  2. 2
    Hiring a professional to redo the door casing
  3. 3
    Undercut the trim and jamb and get the flooring under
  4. 4
    Replace the bad cuts
  5. 5
    Use plinth blocks to cover gaps
  6. 6
    shoving backer rod into the gap and sealing it with silicone

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/Flooring1 person · September 2026

“I recently put down some new vinyl plank flooring, but I'm struggling with how to clean up the gaps around the door frames and jambs.”source ↗

“The door trim was reused and i just didn’t measure the plank to account for that piece correctly, leaving exposed subfloor.”source ↗

Due-Needleworker3354 · r/Flooring · 4 upvotes
r/HomeImprovement1 person · September 2026

“Had LVP pulled out to refinish hardwood underneath, which left us with a lot of doorjam gaps.”source ↗

“Would I just use wood filler/bondo here? Not being square seems like it would be tough to get them to look right, especially since I have no experience.”source ↗

“Or maybe have a woodworker carve some inserts, glue them in and paint over?”source ↗

-Altephor- · r/HomeImprovement · 3 upvotes
r/HomeMaintenance1 person · September 2026

“there's a gap in the upper right corner. The aluminum? flashing wasn't cut to length and I'm wondering if there's a good way to find more of the same stuff or a way to repair it all so that there are no gaps.”source ↗

Zestyclose_Panda_886 · r/HomeMaintenance · 3 upvotes

Where this came up

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