Asked on Dec 3, 2012

Insulation on basement walls?

Woodbridge Environmental Tiptophouse.comKMS Woodworks


Here in Atlanta, is it recommended to add insulation to concrete block walls before finishing a basement? It wasn't done on mine (wood strips & paneling) and I was wondering if it should be re done.
2 answers
  • KMS Woodworks
    on Dec 3, 2012

    not just in Atlanta...insulation is pretty much needed everywhere Because of the basement nature and to maximize R Value, I would use rigid extruded the Dow Blue stuff.

  • I would suggest highly that you pull any wood strips that are directly fastened to the wall and redo the walls. Ideally a air break from behind any walls should be established. Many people believe that their walls are dry, but in reality they will allow condensation to form on the cooler surfaces in which the wood has direct contact. This results in insects, rot and mold. If your tight for space, you can reinstall the wood back on the wall if you install at least a one inch foam closed cell type panel that is sandwiched between the wood the the block. But based upon your past post, it sounds as though holes were put into the block to fit the outlet and switch boxes. You cannot have any breaks in the insulation. It must be installed tight to the wall, and all joints must be taped to prevent any possible humidity from reaching the block wall. Ideally you should frame the wall away from the block keeping the framing about one inch at least off of the block. Then using spray foam after the wires are installed along with plumbing and cable etc. Foam behind the studs and to make a complete seal. This will prevent any moisture issues within the walls that could cause mold. It tightens the framing making the wall stronger, it prevents air currents from traveling behind the wall for fire safety. Plus offers all sorts of energy savings throughout the rest of the house above. In your case you want to at least use one inch of closed cell foam board taped and glued to the block wall.

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