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

70-year-old concrete floor radiant heat refurbish

brewam | Posted in Green Products and Materials on

I’m in climate zone 6A. I will be removing the 70 year old copper radiant heating pipes in my whole downstairs cement floor. The floor is considered a basement floor, limestone walls(some wood covered), built into the side of a ledgerock bank. One side being ground level. I have to do this 1200 square foot project as economically as possible. We are not quite certain how much further past 4 inches we are able to go as of yet. Our plan is to remove the inside cement floors, remove the copper pipes, lay some gravel to level, put down the NOFP Barrier x5, lay wire mesh sheets over it, then tie the pex tubing to the mesh and hand trowel poured cement over top of that. Will this be sufficient as a new heating system? There are some moisture issues due to the current cement having no moisture barrier. I cannot afford to take down the existing woodwork along much of the wall space. We are going to cut inside the walls so as not to damage them.
Any suggestions as too the correct materials for a moisture vapor barrier and the correct steps to do so while remaining on a very tight budget without reducing quality?

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.


  1. Jon_R | | #1

    Why so much work/expense vs switching to some other type of radiator (and perhaps adding above concrete floor insulation)?

    1. brewam | | #3

      Cannot do radiators downstairs because of the layout of the windows and fireplace. No space for radiators. cannot go up on floor because of the lower ceilings in kitchen and hallway as well as walls having antique wood panels on most of wall space. All wood in kitchen and hallway. Plus the fact it is a basement dwelling. The floor heating makes it a more livable space.

  2. GBA Editor
    Martin Holladay | | #2

    I agree with Jon. If you are on "a very tight budget," the best way to proceed is to abandon the hydronic system and install a ductless minisplit.

    If your slab is somewhat damp, you might consider installing a layer of polyethylene above the existing slab, followed by a layer of rigid foam and OSB or plywood subflooring.

  3. brewam | | #4

    Because of the dampness,, being half underground and house sits along the bottom of a gorge makes more dampness, wood not a good idea and the fact of not really being able to go up. Regardless, there should be a vapor barrier beneath the concrete.
    Secondly, The radiant heat sold me on this house 21 years ago. I am not willing to give that up.
    Really just looking for tips on re-doing it the best I can and as economically as I can.

  4. Expert Member
    Dana Dorsett | | #5

    A vapor barrier atop the existing slab with Roth Panels (or similar) under a wood subfloor is probably going to come in a lot cheaper than demolition & rework described.

    Cutting the slab and digging down for a perimeter drain (even if it's to the interior side of your finished walls that you won't be touching) would be sufficient for all but the most egregious moisture issues. Are you seeing liquid water or visibly wet sections of slab?

    What will constitute "...sufficient as a new heating system..." depends on the calculated Manual-J heat load for that space, a critical first step for specifying any heating solution.

    1. brewam | | #6

      The moisture appears along the edge of the concrete along the wall thats 1 story underground. probably moisture from the ground... and no vapor barrier. No.. rest of slab is dry. House was built in 1850. (old brewery), then refurbished with heating system in 1950.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |