Contractor using screw instead of bolt for connector
Contractor using screw instead of bolt for connector
(OP)
I am dealing with a contractor that has placed screw instead of bolt for Simpson connector; he is telling me that it has enough capacity for the applied load.
I am not sure what should I respond to contractor, does he have any leg to stand on? If contractor does not follow the plan, is engineer still liable?
I am not sure what should I respond to contractor, does he have any leg to stand on? If contractor does not follow the plan, is engineer still liable?






RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
It's always better to argue someone's "opinion" with with facts on your side.
And if you find that it is equivilant, then you have an ace up your sleve for the next time.
Wes C.
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There are no engineers in the hottest parts of hell, because the existence of a 'hottest part' implies a temperature difference, and any marginally competent engineer would immediately use this to run a heat engine and make some other part of hell comfortably cool. This is obviously impossible.
RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
If you know that construction was not done according to plans. You have an obligation to check construction for adequacy or have construction corrected to what is shown on plans.
Check the adequacy of the as-built construction. If not adequate insist that contractor make changes. If as-built construction is adequate, inform owner (& building inspector) that the contractor made a field change to the plans and that you have checked the adequacy of field change.
RE: Contractor using screw instead of bolt for connector
If the Simpson connector provided by the contractor has been fabricated for bolts (large holes), I don't think there's any way the connector assembly is going to be adequate by substituting screws for bolts. I would never approve it. Again, why should you accept the liability for something the contractor did that is not in conformance with your design? If this thing fails and someone gets hurt or killed you could be in for a lot of trouble.
It is the contractor's job to build the structure, not to re-engineer it. If the contractor wanted to substitute a different connector than the one you specified, the contractor should have requested the substitution in writing to you before building it. To sum up my wordy response, in my opinion the contractor doesn't have a leg to stand on. When I am made aware of an unauthorized substitution, I always make them remove it and furnish and install what I specified. If it's not feasible to do that, then I make sure that I get paid to engineer a fix for the problem the contractor created. The costs to implement the fix should also be the responsibility of the contractor.
RE: Contractor using screw instead of bolt for connector
Bottom line, if he didn't install the thing correctly and there is nothing in the Simpson literature that supports what he did, I wouldn't except it.
RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
As others have noted, particularly SperlingPE and UcfSE, there are practical and liability issues associated with such a review, evaluation, and response to the contractor.
If you are the Structural Engineer of Record, the you have already stated in the design what you want to see from the contractor. Contractors often substitute systems THEY deem to be "equivalent". Such "equivalence" must be proved by the contractor at his expense. This is probably covered in the construction contract. He's trying to substitute something that is less expensive for him and get you to approve its "equivalence" at no cost to him. Don't buy it.
Have him prove, through a licensed professional engineer and test data that the substitution is equivalent to your design. If he does so, then you can accept it with some level of RELIANCE on the other engineer (that helps your liability). If he does not do so, stick to your guns.
Ron
RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
I have the note on the contract plan "The Engineer / Designer will not be responsible for any changes, deletions or substitutions of materials or methods without his prior written approval", I am fully relying on this statement on the contract plan to release me of any liability, but I have a note for Structural observation on the plan to call the engineer and that was the time I notice all the changes and wrote the letter to owner,I have given a letter to the owner of my concerns and release of liability and the owner said, he gave it to the contractor. I am not sure, if observation can cause any problem, was I responsible to check the job site all the time or the contractor was responsible to call me for observation and even observation makes you liable of his changes done?
RE: Contractor using screw instead of bolt for connector
RE: Contractor using screw instead of bolt for connector
1) Remove the screw and place a through bolt.
Or,
2) Have the contractor fax me the information proving that the screw has the same capacity as the through bolt.
On something like this, he won't be able to come up with a capacity matching the required for the screw, so he won't comply with your request.
Tell him you will not be submitting a letter to the city or building inspector that the building was built to plan to the best of your knowledge. He can either change to the through bolt, or hire another engineer who is willing to stamp the design using the screw. This will be enough to make him change to the through bolt.
RE: Contractor using screw instead of bolt for connector
I have had numerous cases where Simpson engineers have given me some direction on whether to accept some of the more unusual substitutions that come up. Also, it gives them a heads up on who is using their products in a bad way.
RE: Contractor using screw instead of bolt for connector
Fyi, have been in a similar situation twice. In the first instance, my office was thrown off the job by the Architect after writing the letter. Archie did not want to distress the Owner with the concerns that were raised. But we fulfilled our primary responsibility to the public by raising the concerns. In the second instance, the code official understood the concerns and required the Contractor to do what was asked of him on the drawings. Great deal of grumbling and consternation, but the building was done properly.
What I'm saying is that such a letter tends to get everyone's attention really quick. Just be factual and stick to your guns, and let the chips fall like they're going to. You know more about how this building works than anyone else.
Is there an Architect on the team? Is he listening to what your concerns are?
RE: Contractor using screw instead of bolt for connector