GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Process and product to fix concrete slab surface issues prior to framing over them?

lightnb| Posted inGeneral Questionson

I have some issues with the slab that was poured for a garage, and I need to frame an interior wall over a bad area.

The slab was poured with a bit too much water (5.5 slump) on a hot day in July. I think this caused some water to get trapped, which caused a top layer of concrete, about 1/4″ to 1/2″ thick to peel off and sound hollow under some spots. Also, the floor isn’t perfectly level, as the troweling machines were put on it too soon.

What products and process should be used to correct these surface defects prior to framing walls over them?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. Walter Ahlgrim||#1

    Was the new slab poured over a dirty old slab?

    Best practice is not to pour a slab less than 3 inches thick.

    If you are trying to level the floor you need to use a specialty product.

    Jack hammer time?

    Walta

  2. lightnb||#2

    No, it's a new slab, monolithic. About 4" in the middle. Lots of mud got tracked in because it never stops raining.

  3. matt9923||#3

    I would have the contractor fix it. I have learned the hard way to get a contract for everything i sub out witch as of lately is almost nothing. The trades disgust me these days. Seems the only way to get a job done right is to hold money until its right. Nobody is happy by the end of it.

  4. Matt F||#4

    That is definitely not an acceptable result. Is there some reason the contractor is not on the hook for fixing it?

    There are products that can level all this, but they really work best with something to adhere to. They are also not cheap and with an open slab, it is likely cost effective to tear it out.

  5. Walter Ahlgrim||#5

    I say do not pay a dime to that contractor until he has removed the slab completely and poured an new one.

    That work is totally unexcitable.

    Walta

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |