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Siding over Cinder Block


I just bought a house that was built in the 1950s. An addition was built in the 1970s. The main part of the house has cinder block construction with the addition being wood.

My neighbor, who has a vinyl-sided house, told me that her house is actually cinder block, too, but that previous owners put vinyl siding over the cinder block.

I'm noticing some cracks in the cinder block of my house that need to be repaired. I can also see where repairs have been done in the past, both minor (caulking) and some a little less minor.

What are your thoughts as to the benefits/drawbacks of putting vinyl siding over cinder block?

Part of me thinks it is like putting lipstick on a pig...you are just covering up repairs that need to be made. On the other hand, it sure looks good!

Thank you.

A. Spruce
Re: Siding over Cinder Block
Loreen wrote:

Part of me thinks it is like putting lipstick on a pig...you are just covering up repairs that need to be made. On the other hand, it sure looks good!

This is EXACTLY what vinyl siding is and does, it is a despicable product that actually devalues a home for the very reasons you state. If it were me, I'd figure out why the cracks in the blocks were appearing and resolve this issue first, then have the cracks repaired and then skimcoat the whole thing with stucco, which will be a permanent fix, not "lipstick".

Good luck. :cool:

Re: Siding over Cinder Block

Ditto to Sprucey's post. To install vinyl sidding you would have to install furring strips which could further damage the block.


Re: Siding over Cinder Block

Rather than true stucco, how about a Dryvit type synthtic stucco. The styrofoam upon which it is affixed would also afford considerable insulation value where I doubt there is any significant amount. Fastened to cement block, the past moisture problems of synthetic stucco would be avoided. This has been common in Germany since the 70's.

Re: Siding over Cinder Block

Before covering the block with anything water vapor impermeable, I'd check the moisture level at many locations to see how wet the walls are, because you will be sealing any wetness in. Then it can cause mischief.
It's desirable from an energy efficiency perspective to insulate masonry walls on the outside (weather side) because you then can take full advantage of the thermal mass, which means that heat inputs will be fewer and further between, as the mass of masonry regulates the interior temp and the outside insulation slows the ultimate loss of heat through them.
If you can control the humidity levels inside the block wall, you could make your home much more comfortable for lower heat and cooling costs.
Maybe open cell spray foam on the outside , and then some type of stucco (lime stucco will allow moisture to pass thru, as will the open cell foam.)
Attaching furring strips for vinyl, BTW, is just a technical hurdle, and a smart and safe attachment protocol could be developed (so don't let that stop you). I would have any cracks repaired first so you are not just glossing over problems.
The guiding principle must be "Can the walls still breathe?"

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