Insulating a 1950’s concrete block home in a southeast North Carolina
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I am in the process of purchasing a home built in 1959 that is stucco covering concreate on both the inside and outside the house. The interior walls are also concrete covered in what appears to be stucco.
The home is located in Southeast North Carolina. It is about 1000 square feet. It has a lot of insulation in the ceilings, but it is my understanding there was none placed inside the block during construction. I have only looked at it in the winter. The walls feel very, very cold. At some point in time, they replaced all the windows with double-pane windows that seem to be of decent quality. The HVAC unit is a 3-ton 9seer unit (That really needs replacement). That is scary to me that someone would install such a large unit for a 1,000 sqft home. The bottom line, the walls need insulation. I thought about insulating the outside walls on the interior side, similar to basements. The issue I see here is that the interior walls connect to the external walls and would provide a thermal bridge. But those interior walls would provide a lot of thermal mass.
What’s the best way to handle this?
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Replies
The easiest way is probably EIFS. You can put 3"-4" (R16+) of insulation on the outside with a new stucco-like coating. This avoids the difficulty of dealing with interior wall intersections, utilities, etc. It also brings all that thermal mass inside, so you even out night-day swings. EIFS gets a bad rap because of water problems, but EIFS was designed with masonry walls in mind. You can used grooved foam, adhered right to the paint. Window sills can be a bit difficult to detail. So can eaves. If you want to stop thermal bridging, you might have to do some chipping around windows and other openings. Still, it's not a bad option.