curb type question

[dmi]

Please look at the attachment and offer an opinion, if you have one the age of this type of curb. When did they start using it and when did they stop?

thanks for your help

[Jim Frame]

FWIW, a patent application for that type of iron-edged curbing was filed in 1890. See

http://books.google.com/books?id=2CQ4AA ... 22&f=false

for more information.

Another reference for a particular type of edge bar from 1920 can be found here:

http://books.google.com/books?id=IJjmAA ... 22&f=false

With regard to the latter, it looks like the distinguishing feature is the way in which the embedded steel is formed. If you can get a look at a spot where the concrete has been chipped away, you might be able to determine if it's the 1920 type.

Good luck!

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[btaylor]

Definitely see that all over San Francisco. Total guess is early 20th century, up to 1930s or so. Seems like prior to the 19th century they used granite, so those would be the first replacements. I would be interested to see what more experienced SF surveyors say.

[Jim Frame]

Prior to the 19th century there wasn't much of any curbing there at all. The Presidio wasn't established until 1776. Didn't they use granite curbing through much of the 19th century?

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[btaylor]

Woops, my bad. I meant 20th century instead of 19th there.

[Greg Ippolito]

In my experience, that type of curb is typical in SF suburban subdivisions post 1930’s, or in areas that no longer have the original granite curbs. Not entirely sure when they stopped using them. Be sure to look out for surveyors hash marks in the metal. I’ve found them in a couple different areas.

[dmi]

The subdivision was recorded 12/20/1912. Much of the subdivision has curbs with steel molding. At a number of corners there are granite curb, and quite a bit of the curb with steel molding has been replaced. In a number of other subdivisions from the same era, the same type of curbs exist, and as Greg indicated the steel has been slashed at what appears to be lot lines produced. I have seen some that have been punched in the shape of an arrow or as a slash line made up of three or four punched.

Wow Jim you are awesome, thanks for the links.

[Jim Frame]

Don't thank me; Google did all the work.

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[btaylor]

Jim's link indicates this steel curb effect was considered "new" in 1920, so my guess was incorrect. I suppose one should then assume 1920s.

[Greg Ippolito]

Dane I’ve seen a very similar situation in the West Portal area. There is a 1920’s – 30’s era development with mostly concrete/metal curb and granite at the curb returns. I normally would assume the granite came first, however I have seen parts of town where the granite curb was moved to make a wider roadway. It can be tough to tell. It’s definitely worth taking a look at the sidewalk width shown on the city block and grade maps and compare it to distances shown on the block diagrams. You can sometimes determine if a curb has been moved. It may not apply in your area, but you never know. One other thing I’ll do in a pinch is look at historical photos on the City library site. You can search by street name, subject, neighborhood etc… It’s a shot in the dark but you just might find a photo of the area you’re working in.

http://sflib1.sfpl.org:82/

[btaylor]

Yes those granite curbs seem to be in 4-6' lengths and they seem to be "easily" (so to speak) moved and replaced. When they have widened the roads, you find those cut "L" marks make no sense whatsoever. The block diagrams are great for proving out when the curbs are closer to the buildings than they were back in the day.

[dmi]

On one project where there are curbs with steel bar the curbs are stamped with a "Union Made" stamp and what appears to be a 1932 date.
The photo in this thread is from a subdivision recorded in 1912. I have seen property reports with "year built" range from 1912, 1924 and recent demos and rebuilts. There is a neighborhood group on line for this area and they have posted photo's of the neighborhood from the early days.
Many times the curbs are visible in those photos. I do not recall the detail being good enough to see if they had steel bar or not. I routine look to see the age of construction and for photos of blocks I am working in.
Thanks for the link Greg

[Anthony Maffia]

The curb appears to be monolithic, so you could also look at the box for a manufacturing date.