California Surveyors Forums

When splitting curbs, do you prefer FOC or BOW as a line of shots? Why?
I tend to use FOC, when possible, and using "Best fit line" command in Autocad.
My question is when constructing the curbs and walks which line is built with more care, FOC or BOW?

Absent detailed knowledge of how the improvements were built, and other things being equal (e.g. a visual inspection of the improvements doesn't reveal an obvious preference for one line over another), I lean toward back of walk. Back in the days when I was doing a lot of construction staking, that's what we'd stake to for monolithic improvements, and face of curb means dealing with the batter. But as with so many field decisions, site conditions are going to weigh more heavily than any rule of thumb, so I'm not sure there's much value to be found in a general preference.

I would use back of curb, (vs cf) cause that's what the curb and gutter guys set their strings to, both vertically and horizontally for the batter boards. I would also use the back of walk and see how that fits. You may even mean the two "splits" which shouldn't be much of a difference. Whichever one you use, better make sure you have a distance from the curb to the walk, just so you know what it is.

The standard layout feature in Southern California is the face of curb. In most Southern California cities, the face of curb is the basis for measurement or verification to the right of way, i.e. ten feet from face of curb to ROW.

Are you splitting curbs to locate otherwise unlocatable right of way? That sounds like old construction so don't let what you set today for curb machines or otherwise guide you in deciding what to use. Maybe map both and choose the one with lowest best fit residuals. I would usually say face of curb, but I know it varies around the state. In my experience face of curb is nearly always an even foot from R/W. Not so for back of curb or back of walk.

I agree with Bruce Hall. I have watched thousands of feet of curb formed with the VERTICAL back form first.
The problem is that portion of the curb is not usually visible now.
Eyeballing the curb face with the tape flush with the top of curb is the way I was taught, but there were no rods/reflectors then, so holding the rod tip at the intersection of the curb face and top of curb is questionalble without a mini prism.
I use 0.25' back of curb face to locate improvements with greater precision than a mere topo shot.

Well said Dave. Not so much about mentioning my name but your last three lines, you are right on.

If the goal is to reestablish the center line, it becomes irrelevant. if you measure from one side of the street, let's say to the face of the curb, to the other side at the same location - whatever it is and wherever it is, and then split the dimension, assuming the improvements were uniformly constructed, you will inevitably get the center of the street based on the constructed improvements.

mpallamary wrote:If the goal is to reestablish the center line, it becomes irrelevant. if you measure from one side of the street, let's say to the face of the curb, to the other side at the same location - whatever it is and wherever it is, and then split the dimension, assuming the improvements were uniformly constructed, you will inevitably get the center of the street based on the constructed improvements.

I was going to add something to that effect. Unless there is something odd with how they created the improvements on each side of the street, I find I will fit people within a tenth or better once it is said and done, so seems like people are overthinking this one.

Michael, sounds like you split a few curbs in your day :). That is where we use to start when no center line was visible. Guys today are all about radial from a known point and if they can't find a starting point .....call the office :) Jp

I was going to reply in response to Mr . Frames comment on "holding the back of walk", but Mr. Pallamary said it for me. I am pretty sure, it is somewhat jurisdictional how the improvements are "staked". I worked many years in LA, Orange and San Diego County, and it was always to Face of Curb. When I relocated to Sacramento in 1988, it was hard to get used to the reference "Top Back of Curb" or Top Back of Walk", but, it is the norm in Northern California (for the most part. Quite frankly, an offset to a vertical component still seems odd to me (as opposed to Back of Curb or Back of Walk). Anyway, that may be the answer to the question, in that, when in Rome?

Quite frankly, an offset to a vertical component still seems odd to me

Since the stake almost always features a cut/fill, the "top" indicator (as in TBC or TBW) makes clear what the cut/fill references: not subgrade, not flowline, but rather top of the finished improvement.

"Since the stake almost always features a cut/fill, the "top" indicator (as in TBC or TBW) makes clear what the cut/fill references: not subgrade, not flowline, but rather top of the finished improvement."

I have heard this so many times before, but I am talking about the offset, written at the top of the lath, which has nothing to do with a vertical component. It should be 3' BW in lieu of 3' TBW. The Cut/Fill can certainly be TBW or TBC. This is just a Sacramento thing Jim, nothing more, nothing less. It is a different world in So. Cal.
MJW

Does it really make a difference in the end? The most affluent neighborhood I ever surveyed to this point required splitting curbs. When it all broke down, there was no prorating, there was only holding weird hundred year old hubs and iron pipes that just happen to fit. Of course nobody else ever bothered to find them. It was really something to break the block down by curb split and then find old things in the ground that fit record.

This is just a Sacramento thing Jim, nothing more, nothing less.

Perhaps we should call it a Northern California thing, since I've seen it in use from Stockton to the Oregon border.

.