No announcement yet.

Insulating old house


Forum Top GA Ad Widget

  • Filter
  • Time
  • Show
Clear All
new posts

  • Insulating old house

    I live in a cement block house from the mid 50's. There is 12" of insulation in the attic. Interior walls are studded, plasterboard then full plaster. Exterior walls are furred and aluminum siding. Walls get warm in summer and transfer inside and opposite in winter. I want to remove aluminum siding and furring, install 1 1/2" rigid insulation, house wrap, furring then insulated vinyl siding. Is all this going to be worth the time and cost of keeping the house cooler in summer and warmer in winter? Should I just take off the aluminum siding and replace with vinyl? Windows were replaced last year with dual glazed, argon gas filled, E glass. That sure helped this winter. Thanks for any feedback.

  • #2
    Concrete block has voids or openings in the block. When placed together the openings sort of line up with the holes beneath and above it. You can pour vermiculite into these holes which will in effect insulate the block or take up the otherwise dead air space within the block. Once the inside heats up from radiated sunlight it will retain this heat for quite a while and in the winter convected heat from the room will keep the blocks warm, thereby eliminating condensate or lessening it on the outside surface.


    • #3
      I think a lot more info needs to be obtained before a good fix can be recommended. An 1 1/2" hi-r value sheating (DOW is excellent) possibly would be a good remedy for retaining heat. What you really need is a good thermal break between you and the outside. The higher the density the better the r value, also the higher the price. Concrete block on the other hand is great for heat/ cold conduction. You need to break that continuity. On a block wall I question how much value a house wrap would give you. This product is mainly used for air infiltration problems.


      • #4
        I agree with Homerepairguy, the house wrap will do very little (if anything) for a block construction.
        Hayzee has a good idea with filling the concrete blocks with vermiculite if you can get access to the tops of them, vermiculite is cheap, make sure you get it from a pool wholesaler, I built an inground pool last summer and the price of a big bag of vermiculite was between $7 and $25 for the exact same thing.
        Blown in attic insulation offers about R3/inch so @12" you have about R36 in your attic, most places now are R49 for attics.

        silver faced rigid insulation offers about an R7/inch
        vermiculite is about R3/inch
        drywall is about R3/1/2"
        insulated siding about R4

        if you could do the vermiculite, insulated siding and the 1 1/2" rigid siding a total of approx. R17, you would be over what is code compliant for external walls.

        Hope this helps
        Little about a lot and a lot about a little.
        Every day is a learning day.