Structural Engineering CAD files used by contractors
Structural Engineering CAD files used by contractors
(OP)
During the last year or two, I have been asked to provide a copy of my CAD drawings to surveyors. They want to use the foundation drawings with their GPS-guided equipment. Is anyone else being asked to do this?
Also, the fire protection contractors are regularly asking for the framing plan CAD files to help with their designs.
This is a bit like the BIM discussions. In the future, how much more are others going to request our CAD files for their use? Should we provide them? Just wondering about other peoples' thoughts on this.
Also, the fire protection contractors are regularly asking for the framing plan CAD files to help with their designs.
This is a bit like the BIM discussions. In the future, how much more are others going to request our CAD files for their use? Should we provide them? Just wondering about other peoples' thoughts on this.






RE: Structural Engineering CAD files used by contractors
FWIW: We routinely provide our CADD files to contractors, subs, and fabricators upon request. We first make the requesting party sign a waiver stating that the files are for the preparation of shop or layout drwawings only, and that the user is using them at their own risk, and are responsibly for checking all dimensional accuracies, etc.
Its a fairly tightly worded diclaimer and waiver.
We do not charge for the files.
RE: Structural Engineering CAD files used by contractors
I would be very reticent to send out any electronic drawing files unless they can be locked against any changes and dated.
Mike McCann
McCann Engineering
RE: Structural Engineering CAD files used by contractors
All that aside, I asked the question mostly to get a feel for how prevalent the sharing of files for use by various consultants/sub-contractors. Mainly besides steel fabricators.
RE: Structural Engineering CAD files used by contractors
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RE: Structural Engineering CAD files used by contractors
RE: Structural Engineering CAD files used by contractors
Similiar to your OP, we have been getting more and more request from surveyors in the last 2 years. They plug the AutoCadd files into their total stations. They say it helps speed things up.
They need the elctronic files for this.
We routinely send them the files after they sign the release.
RE: Structural Engineering CAD files used by contractors
On many projects that I have been involved with the cad techs end up redrawing the exact details that have already been drawn by the architect and engineer. One thing we don't do is photo copy details from architectural plans and use them as part of our shop drawings. That practice seems to be wide spread among steel fabricators, although most specifications prohibit photo copying the architectural plans.
Having cad drawings of the architectural plans can also reduce the number of RFI's we submit. For over half the jobs we work on when we lay out the framing plan using the dimensions given on the architectural drawings, the building will not close.
It is not uncommon for us to send an RFI out questioning a dimension only to have the architect pull something off his drawing giving us a dimension that we know is wrong.
When we have the architects cad files we can go in and examine the layout and often resolve our issues with out sending an RFI out.
RE: Structural Engineering CAD files used by contractors
Anyone with half a brain isn't going to tamper with electronic drawings because they know they'll get busted, and anyone stupid enough to bother will be easy to bust.
RE: Structural Engineering CAD files used by contractors
We always remove our seal before giving them to anyone.
RE: Structural Engineering CAD files used by contractors
Don Phillips
http://worthingtonengineering.com
RE: Structural Engineering CAD files used by contractors
The building was laid out by the structural engineer. Although we didn't have cad files on this job we didn't need them. Using the dimensions on the drawing we built our wire frame and agreed with all the elevations the engineer showed on his details. The structural drawings were so accurate that we thought the engineer had used a 3-D cad program. We found out latter that he had just accurately worked everthing out.
As a side note I work on glulam shop drawings. The drawings included fabrication drawings for both wood and steel hangers. We send our Auto-cad files to our steel fabricators who in some cases will imput them directly into their c & c equipment. This was a big change for us because in the past we checked the dimensions shown on the steel drawings but not the cad files. Now on our steel weldments we have to check the cad files for accuracy.
RE: Structural Engineering CAD files used by contractors
Charging for CAD files would make it seem like you are charging for a product.
What is our product as structural engineers?
If you don't charge for the files and they are used by a supplier to produce shop drawings, are you sure that this time savings (by the supplier) is reflected in their bid so that the owner actually saves money? Or did you just put additional money in the pocket of the supplier for no consideration?
I think these questions should be addressed in the spec's. If you will provide CAD files for supplier's use should be stated in the spec's. If there is a fee, that should also be stated.
RE: Structural Engineering CAD files used by contractors
On the latter issue, the federal government made file-sharing absolutely safe when they enacted E-sign bill years ago!
AIA promotes the practice of Digital signing (not the same as “digitized” signing). See the AIA paper “13.03.05 Electronic Data Transfer: Electronic Signatures” at http://www.aia.org/bp_chap13, and I’ve also attached it here.
When it comes to digitally signed files (whether .DWG’s or .DOC’s or Email messages), the authorities agree we are GUARANTEED that 1) the person (or business) that sent the file is who they claim to be, 2) the drawing has not changed in any way, either intentionally or accidentally, since it was signed, and 3) the signer cannot later disown it, claiming the signature was forged. That’s pretty iron-clad!
For example, AutoCAD (back to v2004) includes the utility (called “Attach Digital Signatures”) which really IS as easy and painless as the AIA says. You can get a free digital ID from http://w
Aside from the issue of whether or not you WANT to share the files, any 2 parties who DO want to can easily share files without any future worries of file alteration.
Does anyone know why more engineers don’t use Digital ID’s to practice (truly safe) file-sharing?
RE: Structural Engineering CAD files used by contractors
Don Phillips
http://worthingtonengineering.com