What's Missing in Performance-Spec Drawings?

1/17/2019

For those who regularly bid and/or review "performance-specification" or "delegated-design" drawings, what important pieces of information are often left out?

In other words, what should engineers always include for you to price or review a job effectively that you often don't get?

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5 Comments

Jon Sullivan

1/17/2019 10:07:46 am

A helpful part of this discussion would also be - what information do you frequently get on drawings that is not helpful and makes it harder to do your job?

Joe Meyer

1/17/2019 03:57:43 pm

Agreed! For whatever reason I still see service lines stub up and into the building over 10 feet in from an exterior wall, without any covered trenching or regards to floor types. Not good.

PETE

1/17/2019 10:27:43 am

I've run into preaction systems with linear heat detection that are in a Class 1 Div 2 Hazardous Location. This was where there were H2 generators for lift truck fueling. The FP drawings don't necessarily call it out, and it may not be caught in the permitting review, but it is implicit in the Electrical drawings that everything in that area will be C1D2 compliant. That means for the linear heat detection, you will need to purchase the listed intrinsic safety barrier for however many feet of cable they're listed for. I've also worked on jobs on which they are processing their own water, and it wasn't clear from the mechanical equipment matrix which pumps are being used in which location, how they are designed to be set up (i.e. series or parallel). It makes it difficult to size a pump without water supply information. Also, it may be necessary to infer from the use of the building some of the design constraints, i.e. if it is for food processing in the US, then it will likely have to be a USDA inspected facility which means corrosion resistant sprinklers and any exposed pipe is stainless within wash down areas. I think these scenarios can be best addressed by someone with experience on a case-by-case basis, and with more particular details on the type of project. When in doubt, RFI it. With a formal RFI during the pre-bid the estimators often come up with questions that the engineers haven't even thought of, and they are compelled to answer you, sometimes with a little nagging being necessary.

Dan W

1/17/2019 10:51:43 am

FPE's should only provide the following (IMO):

-Identification of the scope of work
-Identification of the applicable codes and standards
-Occupancy Types/hazard classifications
-Type of system (wet/dry/preaction) including density/area and an available water supply.
-Additional structural supports as needed
-Water quality issues (MIC)

Beyond that, routing mains/BL (when there isn't a structural concern), sprinkler layouts, and other design specific items really should be placed on the installing contractor (If it has a cut sheet, leave it to the installer essentially). This is for MOST projects, but there are some exceptions.

This is detailed in the link below:
https://www.nspe.org/resources/issues-and-advocacy/professional-policies-and-position-statements/sfpenspenicet-joint

PETE

1/17/2019 11:27:04 am

Dan,

The document that you linked goes to describe a multitude of functions of the FPE that aren't listed in your assessment (including laying out and calculating systems). IMO the SPFE/NSPE/NICET document gives a broad overview of FPE responsibilities, and the flaw is that it assumes that we engineers need the societies to define our scope of work for us; we do not. The best part of that document are the words, "include but are not limited to". For example, as an engineer I am going to calculate the most hydraulic remote and the most hydraulically demanding "typical systems", but those calculations are used to determine whether the overhead system demand or the fire flow demand is greater, and whether or not the water supply is adequate or if a tank needs to be specified (they are for my records). They do not eliminate the need for the contractor to calculate "their" systems. I have also worked on jobs in which the Electrical engineer wanted to specify a non-listed transfer switch for auxiliary fire pump power and place it in an electrical room 1000 feet away from the pump- which is not allowed by NFPA or the NEC. Additionally, engineers function to help accurately predict budgets for the builder based on design constraints that we recommend so that there aren't ongoing disputes about change orders delaying the project timeline. I'm sure most sprinkler contractors would rather be hit with the specs on the front end than be hit with the remediation points in the review. This is also why there are differences between the permitting package and the bid package. Many of these specs are initiated by the owner/builder, because don't want a build package that merely satisfies the compliance standards.

What's Missing in Performance-Spec Drawings?

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