Protecting drawing

Hello all,
I have a queery if anyone can help? My company is producing
drawings for contractors. So that the contractors cant alter/tamper with
the drawings, we PDF the drawings. However, the contractors are want cad
drawings that they can scale dimensions from. Does anyone know of a way in
which you can password protect drawings so that people can view them but not
alter them?

Thank you for your help

Steve

 

http://www.cadlock.com/


--


MichaelB
www.michaelbulatovich.com

No warranties are implied or expressed....

 

If your contractors are scaling drawings, then either the contractors are
incompetent, or the drawings are incomplete (not properly dimensioned). The
age-old rule for competent contractors is "DO NOT SCALE THIS DRAWING." If
they can't figure out how big to make something, it's their responsibility
to contact the designer.

That being said, CADLock will do what you want (see Michael's post).
___

 

If they need to scale dimensions from a drawing, you aren't dimensioning
them correctly.

 

In a previous post THE REBAR GUY says...

Not to throw cold water on your desire to to a good job there are some
liability issues associated with sharing of Cadd files. Although it
shouldn't happen, there are a few things that MAY cause problems:

1. Overwriting of dimensions. Cadd drawings are supposed to be drawn
accurately, but it is not uncommon for a drawing to have overwritten
dimensions. This is bad practice and should be discouraged. If you use
the cadd drawing as a base and don't notice the overwritten dimension,
then your rebar take-off will be wrong and the arch/engr can get blamed

2. You've indicated your willingness to the time stripping the cadd
files of professional stamps, title blocks, and other identifying
information, but except in special circumstances the file should not
leave the arch/engr's office with that info intact. In Washington State
(and I suspect most states) any document that leaves the arch/engr's
office MUST bear the professional seal of the architect or engineer
unless the document is indicated as "For Information Only" or
"Preliminary" or some other such indicator.

3. Use of the cadd file gives an implied review and approval by the
arch/engr of the drawing used by the contractor (unless specifically
noted otherwise on the drawings.

Finally, this is an area where design professionals are still working
out many of the liability issues and have not yet gotten all the
necessary language to protect themselves into the contract documents.

Having said all that I think it possible to work with the contractor on
the use of cadd files, but the contract language must be clear as the
nature of the electronic document transfer and the uses intended.

Does that help?


Bob Morrison
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA

 

In a previous post THE REBAR GUY says...

You're welcome.

This is a somewhat complex issue. I'm chairman of the Structural
Engineers Assoc. of Washington (SEAW) Professional Practices Committee
and you've just given me an idea for an article for an upcoming
newsletter. I plan to discuss the pro's and con's of giving cadd files
to contractors and how we might better work together to get the job done
in a timely and correct fashion.

 

Bob

It's all the thing to work in Partnership here in the UK

Get the contractor involved at the time of undertaking the feasibility
drawings. Let him have an input into the design so that it's more
buildable etc etc. Partner the supply chain etc to gain further
savings.

Has not Egan Principals got to the USA ???

We are working at eliminiating conflict, and putting lawyer out of
business. Partnering is not a soft-option, I've just completed a
project before time, within-budget, and to a better quality than the
client original specified, but nearer/ better to what the end user
wanted.

We are using the NEC form of contract and Open Book Accounting.
with Pain and Gain for all the partners.

We have already seen where we can improve on the next scheme,
and save more cost. The clients cut of the savings goes straight back
into the rolling program so he gets more units for his money.

As a Structural Engineer, I have no problem letting the RC Flooring
Contractor, Truss Supplier or M&E Contractor having a copy of the
Contract documents electronically (DXF, DWG.)

At the end of the day the Architect checks the dims and I check the
calcs. Working for the Local Authority I also check the Calculations
for Building Control purposes.

Regards

Alan (Cadalot)
B.Eng.(Hons)., I.Eng., AMIStructE, MaPS and all that stuff......

 

I just wanted to point out one thing (and maybe it was just a slip of the
tongue but....):

You said "Before CADD...." well, what's preventing you from doing it the
old way? Obviously you could trace a CADD printout just as easily as you
could a hand drawing. My guess is that you can do your job quicker &/or
(but most likely &) more accurate using a CADD "base". While I agree that
getting a copy of the already drawn CADD file would greatly reduce your time
(and eliminate any inaccuracies you might make redrawing it - not that I'm
saying you would!). I also see and deal with the other side of the coin. I
don't like to give out my CADD files. There's a number of reasons for it
(i.e. Liability, proprietary blocks/details, lack of control once it's out
of my hands, etc.)

What probably would be ideal in your situation, and I'd be willing to do if
a sub asked, is to simply turn off all layers except walls/windows/doors and
then wblock that to a new drawing. Then I could send this drawing to you
for your use (ideally you'd xref it into your drawing). This doesn't
totally eliminate all liability issues but does help with the some of the
other normal drawbacks of CADD file sharing. Of course if the floor plan
changed later on I could resend an updated version which your xref would
update automatically. Then you'd just have to adjust any items you drew
that were effected by the change.

I've done this before (i.e. for Interior Decorators, HVAC, etc.) and it's
worked out pretty slick. Obliviously though there's a limit to the amount
of time I want to spend "cleaning" my drawings for someone else's use. The
"walls/windows/doors drawing" would no longer include some info that
everyone might like (i.e. Notes, RCP items, etc.) but it's certainly better
than nothing. Depending upon how I'm being paid would also dictate how much
time I'm willing to spend "cleaning" the drawing (especially if it needs to
be done multiple different ways for multiple subs). Sometimes it's just
easier to not bother and just say "we don't give out CADD files".

Another important point (as Bob mentioned) is what if the drawing is
"fudged" (i.e. dimensions overridden). Then you're just asking for trouble.
Of course I don't fudge dimensions, nor do I allow my people to fudge 'em.
But if they did, then it could turn into a nightmare.

Well, that's all for now!

Michael (LS)

 

Michael

The way around this is to have the very basic structure as a source
drawing that is X-Reffed into other drawings.

So the source would have

Structural Walls and Columns
Door
Windows
Dimensions

The Architect wants his dimensioned plan, his reflected ceiling plan,
his room name and areas drawing, his carpet and floor finishes, his
furniture and other fittings etc. etc.

The basic Source Drawing information that what all other parties are
after, The Electical and Mechanical Guys what to draw their
diagramatic schemes on the plan.

The Floor and Roof Truss prople are only interested in where the
supporting walls and and beams may be with some key dimensions.

The Sructural Guy wants to add beams and any columns where
any structural masonry is not provided. To be able to produce a
foundation plan. Lintel schedules for doors and windows.

So if you built your drawings like that from the start, you would not
have to strip them back.

Alan (cadalot)

 

There is no reason, see my anwers on the other tread....

Alan (Cadalot)

 

In a previous post Michael (LS) says...

I think this is one of the biggest issues. It is all too easy to
"measure" the dimensions off a cadd drawing instead of computing them
the old fashioned way based on the noted dimensions.

If the cadd drawing is not to scale, then who is liable? Most likely
that will be the person who prepared it. I frequently have to correct
the architect's drawings because they have overwritten a dimension. And
that is just to get the basic structural design and drawings correct.
These drawing should be dimensionally accurate, but from a design point
of view if the beam is 3 inches longer it won't make much difference.
But, from a detailing point of view that 3 inches could be a real big
deal.

BTW, I NEVER check the detailer's dimensions, unless it is a dimension
that I specifically asked for. To do otherwise is to assume complete
liability for the detailer's drawings. Something my insurance company
would not be very happy about.

As I said this is an interesting and complex topic which will make for a
good newsletter article. I expect it will stir some of the same issues
we have been discussing here.

 

Bob,

Can/will you post the article here (as well as any reader responses)? I'd
be interested in hearing other peoples opinions & ideas on the topic.

Michael (LS)

 

In a previous post Michael (LS) says...

As soon as I can get the article written and the SEAW newsletter prints
it. Given my work load this won't be anytime in the next month or two
unless I can find some help.

 

In a previous post THE REBAR GUY says...

Thanks for the chuckle. I've been doing engineering since 1971 and
understand exactly what you are talking about. The primary concern for
new projects now seems to be "When can you start?" rather than "I want
the best design possible."