This is my first time installing LVP. The subfloor in this doublewide, for the most part, is in good condition but I have questions about a few areas in the subfloor that I am unsure how to handle.

tilt1First pic is a section 4 feet by 4 inches. Looks like the board was put there to fill a gap for reasons unknown. There's no other "patch" jobs anywhere else. tilt2It's not level and it's tilted toward the wall. I am thinking that I will rip that board up to see why it was installed like that and fix it, possibly just sanding it down and putting it back? mwall1 This is a gap in the marriage wall that runs half the length the trailer, it's over an inch deep. Can I fill it with floor patch? mwall4 This is the marriage wall in the other half of the trailer. This metal strip is wavy and uneven, with sharp pieces where it folded back on itself. Any advice about what to do here? Can I just put the LVP over it? kitchThis section runs about 4" x 4". I'm thinking self leveler here. I appreciate any and all advice.

  • How thick is the lvp? Is there a underlay cushion that goes down first? Is this glue down or floating installation?
    – Kris
    Apr 23, 2021 at 12:34
  • Is the metal piece above the floor? You may need to feather out floor leveler or add 1/4" underlayment over everything or leave out the pad in that area to allow the flooring to span that small void, depending on how thick the LVP is
    – Jack
    Apr 23, 2021 at 14:27
  • None of this looks too concerning except the last, but your description of the "not level and tilted" bit isn't very specific.
    – isherwood
    Apr 23, 2021 at 14:43
  • Thank you for your suggestions.
    – Aimy
    Apr 24, 2021 at 15:31

1 Answer 1


You will most likely need to a mix of fixes. At the edge where the piece is tilted you may simply fill that with a trowel grade floor leveler. If I am thinking correctly, that is subfloor only, not an underlayment you can pull up. The walls are sitting on the floor you see now. Modulars are built as light as possible for towing to the building site so quite possibly if you pull up the floor, you will expose the insulation and floor joists.

The gap in the first picture will definitely need sanding, and perhaps over a large enough area to lower the other side too, but take no more than 1/8" or less off of the surfaces or you will weaken the subfloor too much.

The gap in the 3rd picture can be filled with floor patch as you suspect. If the floor is thick enough it may be able to span over the gap with no filler, but it would be better to fill it.

Typically each maker of laminate floor has their own "flatness" recommendations. It runs from 1/8" over a 5" span to 3/16" over an 8' span and anything in between. Your last picture with the level "ramped up" to measure the end is not the intent of checking for flatness. The straightedge or level used as a straightedge need to be "balanced" over a hump or depression and the ends are checked over humps or the middle is checked over depressions. The way I see the edge at 1/2", may in reality only 1/4...

So again, sanding will be your help on some of the fixes, but do not go down to far. If there is still a dip or ridge that is too high following the before mention guideline, use trowel grade floor leveler to finish the task.

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