Expert: Bruce E. Johnson - 5/23/2011

Question
Hi,
I would like to make an offer on a house built in 1949 in MI that is made of cinder blocks.  Can you tell me what the pros and cons are of owning a cinder block house?

Answer
Hi Joanne, probably the biggest con about a cinderblock home is insulation.  Cinder blocks are hollow and their empty cavities provide little insulation against heat and cold.  It is possible that this home you are looking at, since it is older, has those open cavities filled with vermiculite granules, which was a common insulation back then.  If that is the case then this insulation factor is negligible.  Other forms of insulation for masonry block is foam core fill, sheet insulation applied to the exterior or interior walls, or fiberglass insulation installed in a false wall directly on the inside of the exterior walls.

Since cinder block walls are single wythe generally (one layer of block makes up the wall).  So care must be taken to keep the elements from penetrating the masonry surface.  If the home is just painted cinder block then the paint needs to be kept in good condition to keep water from penetrating through during rain events.  Masonry is not waterproof by itself it needs a good coating on it to make it water tight.  If the exterior of this home has siding on it then this point is moot.

So my conclusion is, I think masonry homes are fine.  I live in one myself. If you have any further questions regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com