My area is an old brick manufacturing community. I am familiar with them and they were used in the timeframe your house was built. Here is one article I thought summed them up nicely.

Here is a link that might be useful: terra cotta blocks

Type .........clay building blocks early twentieth century....into your browser and fly with it. They're commonly used in Europe now too, btw. Another, more complete link, is below. Interesting read.

Here is a link that might be useful: clay building blocks

Thanks so much. I appreciate the help but those were the only two articles I found lol. I'm so surprised that there really isn't much more. The people I work with joked they may have to dig out their text books for me :P

Actually - I may call up the Historic Preservation Board in NYC (where I work) and see if they might be able to help out. If they can't nobody can!

Hi,
I have worked on two houses built with this system, one 8000 sq ft from 1910, and one a few years newer and maybe 4000 sq ft. It makes for a very well-built, dry, yet fireproof structure. Both had poured concrete foundations, and no settling issues.
One typical problem is drilling through the blocks to anchor things like cabinets , etc. The stuff is really incredibly hard.
You can rest assured that it was built to the highest standards of its time, in terms of the quality of everything else; they probably didn't skimp on the floors, framing or any of the finishes.
Casey

Here is a link that might be useful: Load-bearing terra cotta standards

Structural terra cotta.

Here is a link that might be useful: http://historicbldgs.com/terra_cotta.htm

Around here they are called "furring", "fairing" or "faring" blocks. I have no idea where the name comes from. They are hollow fired clay blocks, similar to ICUs. My town had a big brick-making operation at one time, so a lot of clay products are featured in our local housing that are not common in other communities.

The blocks are very tough but have some problems.

When expose to wet soils for a long time unglazed blocks tend to turn back into their original clay over time. This does not make the good foundation material although they were often used in foundations. However, if glazed, they are exceptional foundation material.

The are very hard, but brittle. Standard concrete anchors that rely on friction or pressure don't work reliably. They often crack the blocks. Power loads are absolutely out of the question. Fastening to the blocks is a chore since something like a toggle anchor must be used. I am not aware of any anchor specialized for clay blocks, and believe me I have looked.

I pity the guy who has to hang cabinets in your house.

I'm only a year late to this thread, but thought I'd chime in. We had a house made of clay block and as xoldtimecarpenter said, hanging cabinets (or working with plumbing and wiring) is virtually impossible. We gutted the kitchen and took out the 1950s cabinets (light, hanging by toggle bolts). Our solution was to build a wall of 2x4s against the block wall. It was fastened to joists above and below, and we used adhesive against the block. That gave us room to work with plumbing and wiring, and gave us actual wood from which to hang the new cabinets. We had to re-trim the windows, but a loss of 4" of the room didn't really make much difference in the end.

HI Everybody I am currently working on a project in which I wanted to include terra cotta block but can't find a manf./source for these rustic blocks.( used for decorative purposes) Does any one have a manf. I might contact ? Thanks in advance for ya'll assistance