demo plan responsibilities
demo plan responsibilities
(OP)
I discovered a likely collapse mechanism in a 100 year old theater 5 years ago, produced a report, suggested shoring. Bow string trusses with rotted bottom chord bearing ends. Install columns through the roof to support the trusses. Long story short, another firm designed the shoring, the new owner is tearing it down, and the city wants my stamp on the contractors demo plan which I just got last Friday.
I would like to "bless" his demo plan with a letter that also relieves me of all associated responsibility (likely a dream of mine). Otherwise, they are going to have to pay for another structural evaluation (the roof has been left open for 5 years) along with a complete set of demolition plans, detailing temp shoring, xbracing, etc.
This is a relatively large demo project for myself and the contractor. I do have a lot of confidence in the contractor, but I'm nervous about even getting involved, considering all of the possible ways a project like this could go bad, especially when there is such an apparent rush to demo. The walls could fall onto
lower nearby structures.
So what is my question? Where is the line typically drawn between the contractor and the structural engineer on something like this one? How much latitude do you give the contractor in a demo, especially when you are suggesting means and methods? I feel like I need to be on site the whole time.
thanks for any thoughts
I would like to "bless" his demo plan with a letter that also relieves me of all associated responsibility (likely a dream of mine). Otherwise, they are going to have to pay for another structural evaluation (the roof has been left open for 5 years) along with a complete set of demolition plans, detailing temp shoring, xbracing, etc.
This is a relatively large demo project for myself and the contractor. I do have a lot of confidence in the contractor, but I'm nervous about even getting involved, considering all of the possible ways a project like this could go bad, especially when there is such an apparent rush to demo. The walls could fall onto
lower nearby structures.
So what is my question? Where is the line typically drawn between the contractor and the structural engineer on something like this one? How much latitude do you give the contractor in a demo, especially when you are suggesting means and methods? I feel like I need to be on site the whole time.
thanks for any thoughts
RE: demo plan responsibilities
In my jurisdiction, following a couple of collapses that occured during demolition, the code was changed to require A)demolition plans and specifications prepared by a licenced professional engineer and B) a minimum of periodic site inspections during the demolition process. In each aforementioned collapses people in adjacent buildings were killed.
There are engineers who specialize in this type of work. They are familiar with the Codes governing demolition, the types of equipment typically used (the demo contractor will want to use the largest sized equipment possible on suspended slabs, given that any other non-construction live loads are not present), temporary protective measures and the procedures/sequences implemented. This is only a partial list of what should be specified. As an aside, I am amazed at how little the demolition contractors in my area pay for these enginering services given the high potential for liability.
RE: demo plan responsibilities
Your right on it. There is a lot of pressure coming from the city and the contractor and the owner and I just got involved. So I'm telling everyone we need to take a step back and give me time to understand the current situation, actually do some engineering, and make sure we covered all our bases. I never felt too good about writing a letter "approving" and then saying I'm not responsible. Just trying too hard to be helpful. I'm hoping I can at least keep some height of wall up around this historic theatre perimeter. The tragedy is that it's just the roof trusses, but no one wants to pay to fix them, and they sure don't want to pay an extra cent to tear it down. I'm meeting with the contractor and owner this afternoon to either walk away or come up with a scope of work and a fee that I'm comfortable with.
RE: demo plan responsibilities
I've been in your position before. It's tough telling Contractor's and Owners something that they don't want to hear but after the dust settles I always feel better that the job has been done properly. If they don't like taking the time to do it properly, they are free to go elsewhere. If something does go wrong, regardless whether they rushed you or put pressure on you to accept something that wasn't on the up and up, they will not hesitate to point fingers in your direction. Good luck.
RE: demo plan responsibilities
Pretty freaky. Now I'm ready for that theatre to meet the earth again.
RE: demo plan responsibilities
Dik
RE: demo plan responsibilities
I don't think you can just rely on the contractor to finish the job. You have been onsite and have knowledge of a potentially dangerous situation and will be judged (liability wise) on you response. If there is something that needs to be done NOW to mitigate the situation, it should be in your letter, perhaps proceeded with a phone call. If the walls are 30' tall and can fall in either direction, you better believe I would be insisting on barriers/hoarding/evacuation within any potential fall zone FIRST. Then someone has to step back and come up with an engineered plan for the workers to safely enter the demolition zone and safely continue with the demolition. If a sidewalk or a roadway or an adjacent building or a park has to be temoporarily shut, so be it.
RE: demo plan responsibilities
RE: demo plan responsibilities
RE: demo plan responsibilities
thanks, though...
Dik
RE: demo plan responsibilities
RE: demo plan responsibilities
I was visiting a large renovation in a large city in the Midwest. The demo was on-going. I noticed that a concrete column about 12'' x 12'' had become totally un-braced and was now about 50' tall and possibly carrying a very sizable load. Sure looked that way to me.
So I wrote a short note to the EOR(a very large firm) explaining what I saw and suggested that they take a look at it. BTW - I wasn't even licensed in that state and said so. But my engineering instincts just told me that maybe someone had "missed" this problem.
Well, that letter ended up on the Mayor's Desk!!! Apparently - he through a fit!! The EOR asked me to retract it. I said "NO - just check the damn thing". Couldn't have taken more than 15 minutes.
They fixed it.
But some days - it seems better to stay in bed - but we have our jobs to do - and the first is to protect the health and safety of the public!!
Hang in there.... do what is right...
RE: demo plan responsibilities
In my opinion, you are obliged to inform the City if A) there is an immediate danger to the general public or B) if the Contractor is not moving fast enough or decides to dismiss you. That being said, I have brought the City in on a couple of situations via informal telephone call and not only were they appreciative but they were also helpful. As long as they understand the situation and see that everyone (engineer and contractor) are moving forward quickly, safely and competently, I believe they likley will only monitor the situation closely and let you do your job. Good luck, you may be working late tonight!
RE: demo plan responsibilities
We agreed that he would outline his plan and I would revise. I got the plan on Friday and made it clear that nothing was getting stamped on Tuesday in order to keep going. I reminded him that he proceeded without a plan and has weakened the structure significantly, and we now have people within a potential collapse zone. "What do we do now?" he asks. So far I have only caused more problems in the eyes of the contractor. Very similar to the last time I looked at this building and warned of potential collapse. Thanks again for all the advice.
RE: demo plan responsibilities