Soft, Orange Bricks 4

[phamENG]

Question out there for those of you with experience in old bricks, particularly those created on the East Coast of the US around the turn of the 20th century.

I've noticed these all over the place, and even have a few in the veneer of my house (veneer was built from recycled bricks). You get a mix of colors in a wall, and invariably the light orange bricks are incredibly soft a brittle. See the picture below. You can see at least two that are nice light orange and hollowed out. I can only assume the two that are missing with only trace amounts of dust left behind were the same (the dust is a bit orange). Kudos to the head joint for fighting the good fight, though.

Does anybody know what these things are made of? Given the consistent performance of bricks of this color, I have to assume it has to do with the source clay, but I don't know much beyond this. Has anyone else noticed this?

Sorry: this is in Coastal Virginia for those who may be wondering.

 

[r13]

Yes, the brick was made from clay. In the early days, it was wet molded by hand, dried by sun, and hardened by burning. Depending on its location with respect to the burner, the color differs. At old time, the temperature was difficult to control to be uniform throughout; the lighter colored brick was the result of less heat received during the hardening process, and tended to be weaker.

 

[phamENG]

Thanks, r13. I'm aware of the difference in strength based on distance from the heat source (which is why certain faces have to be directed outward), but I hadn't considered that a brick might be several rows away, leading to a similar phenomenon on all faces. Certainly makes sense, and is a lot more plausible than a different source clay used in some of the bricks and not others.

 

[r13]

Yes, even the same source, the products from every batches differs to a degree too, the key is temperature and heat exposure.

 

[r13]

The fuel was wood, or coal. Bricks were stacked in rows and columns.

 

[Ron]

phamENG....depending on the brick manufacturer and location, those bricks with lighter color likely had more sand particles....essentially a sandy clay before firing. Many bricks because of demand in the earlier brick industry, were quickly fired resulting in a relatively hard crust that was shallow , with the interior being relatively soft. When wetting and drying cycles crack the crust or just from the firing cracks, the interior would leach and the bricks would deteriorate.

I have photos of brick that I have cross-sectioned from that time period showing the crust firing. Will try to dig one out and post it.

 

[phamENG]

Thanks, Ron. The sand would explain the granular texture of what's left as the brick degrades.

I don't have any pictures, but I've seen what you're talking about regarding the shell. I've dealt with a fair amount of historic brick structures, but the light orange bricks have always driven me crazy because I couldn't come up with a good reason. Between your comments and r13's, it makes good sense. Now I'm going to see if I can track the locations where I find them and see if there's a pattern (particularly in the pre-1880's structures).

The area is interesting from a geologic/physiographic standpoint. We're on the coastal plane, but that's subdivided into lowland and upland sub-regions. And then you have pretty different sediments found north of the James River as opposed to south of it (more iron rich, red clays to the north and lots of dull gray and blue clays to the south). I wonder if that'll factor into it at all.

 

[Ron]

phamENG.....yes, you are on the cusp of the difference between Piedmont clays (residual soils) and marine clays. Marine clays are not generally used for brick.

 

[cliff234]

Those are referred to as "salmon brick". It's soft brick. Google the term for additional information.

 

[phamENG]

Thanks, cliff. Never would have guessed that one.

EDIT: Wow. These are absolutely everywhere. Interesting that none of my frantic internet searching for "soft" "orange" "light orange" "crumbling" and all manner of combinations never landed on one of these seemingly endless sites...

 

[dhengr]

PhamENG:
In my neck-of-the-woods, people in the know would understand what I was talking about if I called them ‘Chicago Common Brick’ or ‘Chicago Soft Brick.’ They are attractive for their color variations, and reasonably durable if you keep them out of the weather, or away from migrating water. Sand blasted interior factory walls turned office space, or condos is particularly nice/attractive, I think.

 

[r13]

I am not an expert on bricks, but it is interest to know that clay came with a few different colors, largely due to the effect of mineral/chemical it contains - red, brown, tan, green and white. The lighter color one is rare and preferred in the fine art work though.