Note for "Field Measurements" 2

[Ron247]

I decided to make a standard note for field measurements. I do a lot of this at times and felt a single general note would be helpful. Here is a rough draft. Note #1 is the more common one I see and have used but I have found when others field measure they tend to not think of all the things that are not perfect. Whenever, they get it wrong, they look to my drawings and try to blame it on me. I had someone today who was off by 4" in trying to determine if a masonry block was 8" or 12". He looked at the corner and saw there was 4" from the inside face of one wall to a mortar joint on the intersecting wall. Good old mathematics. 12"-8" = 4". So he deduced this was a 12" block meeting an 8" block. No, it was the long dimension of a 16" long block meeting a 12" block. 4" is also equal to 16-12. I noticed what he was doing and told him it was a 12" block. I know because I had drilled a hole in the wall earlier and checked it. Comments on the note?

 

[WARose]

Those are some pretty good notes. We use to cover it (when adding on platforms and so forth to existing industrial facilities) by saying something like: Contractor shall field verify all existing dimensions prior to work or fabrication of structural steel and/or reinforcement.

 

[CANPRO]

I think your notes make for a good guide for field measurements and possible sources of error, but I would be reluctant to put those on my drawings. Personally, I would use note #1, #4 and then WARose's note written italics. Anything beyond that and you might be opening yourself up to some liability - your notes are very well intentioned, but feel almost like you're holding the contractors hand. A qualified contractor should be able to identify their own sources of potential error based their chosen method of measuring/surveying.

 

[trustthemodel]

In addition to having a note similar to what WARrose is showing, we typically say something along the lines of: Contractor immediately notify A/E team of any discrepancies between information shown on drawings noted in the field. ("information" would include elevations, dimensions, construction, etc.)

Depending on the project there may be a note to coordinate dimensions with any other drawings or trades.

I'm also inclined to believe beyond that is means and methods.

 

[kipfoot]

combining some of the advice above:
1. THE DIMENSIONS SHOWN ON THE PLANS ARE FIELD MEASURED AND ARE FOR APPROXIMATE LAYOUT AND ESTIMATING ONLY.
2. THE CONTRACTOR SHALL VERIFY AND/OR ESTABLISH ALL EXISTING CONDITIONS, DIMENSIONS, VARIATION OF WALL PLUMB AND SQUARE, ETC., AT THE SITE, AND SHALL NOTIFY THE ARCHITECT AND ENGINEER OF DISCREPANCIES BEFORE BEGINNING THE WORK.

 

[JAE]

How about this:

[red]All dimensions shown on the plans and details are taken from original plans, various field measurements, or approximations and are intended for use in design and general estimating purposes only.
Actual dimensions may vary from those shown.

The CONTRACTOR shall field verify dimensions required to fabricate all structural components.

The CONTRACTOR shall also be responsible for all errors of detailing, fabrication, and for correct fitting measurements in the field to verify or supplement dimensions shown on the drawings and shall assume responsibility for fitting new work to existing work.[/red]

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[JLNJ]

Sometimes I prefer to say "field determine" rather than "field verify". In my mind, it makes it more of a directive.

I also like to put notes specifically stating that "actual xxxxxxx not known" so that someone looking at a plan view doesn't think I really know where that duct (that I just cartooned in there).

 

[Ron247]

This note is when I have been paid to field measure a building for someone. The results may be used by an Architect, Owner, Engineer or Contractor. I have done this before if someone is willing to pay my hourly engineering rate. I have a lesser note when I do the measuring for a structural design I am doing. In this case, it is a little of both. We kept finding big errors in the original field measurements. The building is 18" longer than the previous measurements.

but feel almost like you're holding the contractors hand

That is what I am mostly doing. The good ones know how to measure, the bad ones don't. Problem is I am seeing more bad ones. I have the note now where I can delete some bullets if I want to per job but liability is an issue.

JLNJ-I also prefer your suggestion of field determine versus field verify my potential screw-ups.

NOTES:
1. ALL DIMENSIONS SHOWN ON PLANS ARE TAKEN FROM OTHER SOURCES SUCH AS ORIGINAL PLANS, FIELD MEASUREMENTS OR APPROXIMATIONS. THESE DIMENSIONS ARE FOR APPROXIMATE LAYOUT AND ESTIMATING ONLY. DESIGN PROFESSIONALS AND CONTRACTORS TO INDEPENDENTLY FIELD DETERMINE ALL NECESSARY DIMENSIONS FOR ANY ITEM DESIGNED, FABRICATED, SUPPLIED AND/OR INSTALLED BY THEM.
2. DESIGN PROFESSIONAL OR CONTRACTOR TO NOTIFY OWNER, ARCHITECT AND/OR ENGINEER OF DISCREPANCIES BEFORE BEGINNING THE WORK.
3. IF ANY AREA OR DIMENSION THAT OCCURS DURING DESIGN IS CRITICAL, THE DESIGN PROFESSIONAL, SUPPLIER OR CONTRACTOR IS RESPONSIBLE FOR DETERMINING THE DIMENSIONS OR CONDITIONS.
4. DESIGN PROFESSIONALS AND CONTRACTOR SHALL BE RESPONSIBLE FOR FITTING OF NEW WORK TO EXISTING WORK.
5. THE DIMENSIONS SHOWN ON THIS DRAWING ARE NOT STATED AS BEING WITHIN ANY SPECIFIED TOLERANCE.
6. FIELD MEASUREMENTS OF AN EXISTING STRUCTURE HAVE INHERENT ERRORS THAT CANNOT BE OUTLINED UNLESS EXTREMELY ACCURATE AND CONTROLLED METHODS ARE USED. THE FOLLOWING ARE SOME EXAMPLES OF COMMON CAUSES OF ERRORS THAT MAY EXIST IN THESE DIMENSIONS OR FIELD MEASUREMENTS:
6.1. WALLS, COLUMNS AND OTHER VERTICAL ITEMS ARE NOT PERFECTLY PLUMB. MEASURING AT THE BASE VERSUS MEASURING AT THE TOP CAN YIELD DIFFERENT ANSWERS. THE TALLER THE ITEM, THE MORE THE ERROR COULD BE.
6.2. ITEMS MAY BE BOWED OR SAGGED AND THEREFORE MEASURE INCONSISTENTLY ALONG THEIR LENGTH.
6.3. BUILDINGS, ROOMS AND SOME DEFINED AREAS MAY NOT BE SQUARE.
6.4. WALLS OR LINES THAT ARE ASSUMED TO RUN PERPENDICULAR TO ANOTHER WALL/LINE MAY BE RUNNING ON A SKEW.
6.5. TAPE MEASURES AND LASER MEASURING DEVICES MAY BE SLIGHTLY SKEWED WHEN USED. THE LONGER THE DISTANCE, THE MORE THE SKEW CAN ADD TO THE LENGTH.
6.6. LONGER DISTANCES MAY BE COMPUTED BY ADDING MULTIPLE MEASUREMENTS OF SHORTER DISTANCES. THE MORE SEGMENTS USED, THE MORE THE ERROR COULD BECOME.
7. A MORE ACCURATE ASSESSMENT OF THE EXISTING BUILDING DIMENSIONS CAN BE PROVIDED AT AN ADDITIONAL FEE. THE MORE STRINGENT THE REQUESTED TOLERANCES ARE, THE MORE THE FEE WOULD BE.

 

[GeoEnvGuy]

Wow someone gets paid to measure something an I get a note that says

FIELD MEASUREMENTS OF AN EXISTING STRUCTURE HAVE INHERENT ERRORS

What is the client paying for?

 

[skeletron]

CANPRO and GeoEnvGuy have the two best posts in this thread! As much as I chuckled with GeoEnvGuy's, a valid point is raised.

I think Ron's intent is clear but the approach won't work for a "general" drawing (I'm putting "general" in quotes to show that you may have unique, specific packages that require this as opposed to a standard IFC). My suggestion would be to take the notes and issue that as your standard internal procedure (ie. RON-ENG PROCEDURE M-4.5). Then reference that procedure in your notes and use the suggestions above from CANPRO or JAE to have succinct notes.


...but I can't recall if I have ever solved that problem yet.

 

[Ron247]

GeoEnvGuy: In essence, you get what you pay for. If you are joking, point taken. If you are serious, you have never field measured a 35 year old building. I am measuring to give a "footprint" of where walls, columns etc are located. If you need a beam to span between 2 columns that are 25' apart at the floor level, bu your beam is at 20' above the floor, I bet your measurement is not 25' unless you are in something that was built to high-end standards. 99% of construction is not to that high-end standard.

 

[JAE]

You might also want to review any General Conditions or Special Conditions included in the project manual (book specifications) that may be issued as part of the contract documents. Many times these have language in them concerning this topic. You'd want your notes to correlate to, or be somewhat consistent with, those items.



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[Ron247]

Good point JAE