How to bid structural steel work as a subcontractor

Start with what you are actually bidding

Before you weigh a single shape, settle the boundary. On most commercial jobs the steel package splits across separate MasterFormat sections, and the split is where money leaks:

• 05 12 00 Structural Steel Framing. Beams, columns, base plates, connection material, the frame that carries load.
• 05 21 00 Steel Joist Framing and 05 31 00 Steel Decking. Sometimes yours, sometimes a separate package, occasionally split between furnish and install.
• 05 50 00 Metal Fabrications. Stairs, ladders, railings, embeds, lintels, bollards, pit frames, the long tail.

That last one is the single most common scope gap in steel bidding. Miscellaneous metals is a grab bag, it is drawn across architectural and structural sheets rather than in one place, and both the steel sub and the GC assume the other one has it. Decide explicitly whether you are carrying it, then say so in writing. A steel bid that is silent on misc metals is a steel bid the GC will assume includes misc metals.

The second boundary is furnish only versus furnish and erect. These are different businesses with different numbers. If you are furnishing only, the erector's crane, rigging, detailing coordination and site access assumptions are not yours, and your proposal has to say that plainly.

Read the drawings for your sheets, not the whole set

The set is large. Your scope is not spread evenly through it.

• S-series structural drawings carry the frame: framing plans, column schedules, beam schedules, typical details, connection details.
• Schedules beat plans. A column schedule tells you sizes, splices and base plate details far faster than scaling the plan. Read the schedule first, then use the plan for count and location.
• Typical details are where the connection material hides. Stiffeners, gussets, doubler plates and shear tabs are rarely on the plans at all. They live in the details and they have real weight.
• Architectural sheets carry your misc metals. Stairs and railings are drawn by the architect. If you only read the S sheets, you will miss the scope you are most likely to be held to.
• Read the general notes and the specification section. Finish, bolt type, weld inspection and delegated design responsibility all live in the words, not the geometry.

Get the tonnage right

Tonnage drives the number, and bare shape weight is not tonnage.

Take off the frame by mark, get the linear footage or the count per mark, and apply the shape weight per foot. A wide flange beam is designated by nominal depth and weight per foot, so a W21x62 is 62 pounds per linear foot, and that is the easy half of the calculation.

Then add what the shapes alone do not include:

• Connection material. Plates, angles, stiffeners, gussets, shear tabs, bolts. This is not a rounding error. Derive your percentage from your own shop's history on similar framing rather than from a rule of thumb you read somewhere, because it varies enormously between a braced frame and a simple-span job.
• Base plates and embeds. Heavy, easy to miss, and often on a different sheet.
• Moment connections. A moment connection costs materially more than a shear connection in both material and shop labour. Count them separately rather than averaging them into the frame.
• Finish. Galvanizing versus shop primer versus bare steel is a large cost delta driven by exposure. Read the spec, do not assume.

Convert to tons at the end, and state the tonnage you carried in your proposal. See steel tonnage for how the conversion is handled and where it goes wrong.

The three things that blow up steel schedules

These are schedule risks, but they land on your price because the GC will ask you to own them.

1. Shop drawing approval duration. Fabrication cannot start until shop drawings are approved, and approval is not in your control. State your assumed review turnaround as a number of working days in the proposal. If you leave it blank, you have accepted whatever the review actually takes.
2. Delegated connection design. Many jobs push connection design to the fabricator's engineer. That is engineering cost, engineering schedule and engineering liability. If the drawings say connections are by the fabricator, price it and say you priced it.
3. Anchor bolts and embeds arrive first. They are needed weeks before erection, they are usually installed by the concrete sub, and they are frequently supplied by you. Supply and install are two different scopes. See anchor bolt.

What the GC checks when leveling your bid

Bid leveling is the GC normalizing every steel proposal to one common scope so they can be compared. If you know what gets normalized, you can write a proposal that survives it. Expect them to check:

• Tonnage carried, against the other bidders and their own estimate. An outlier gets a phone call, and if you cannot defend your tonnage you lose the job on credibility rather than price.
• Misc metals, in or out, item by item.
• Furnish only or furnish and erect, and if erect, whether crane and rigging are included.
• Deck and shear studs. Metal decking and shear studs are classic split-scope items.
• Who supplies anchor bolts and embeds.
• Finish and inspection. Bolt grades, weld inspection, primer compatibility with fireproofing.
• Unit prices for adds, so they can price changes without re-bidding.
• Allowances you carried, and for what.

Anything you left silent gets filled in with an assumption, and the assumption will not favour you.

Structure the proposal so it cannot be leveled against you

A steel proposal that holds up has five parts, in this order:

1. The number, with the tonnage and the scope sections it covers.
2. Inclusions, listed as items rather than as a paragraph.
3. Exclusions, listed the same way. This is the most valuable section in the document.
4. Clarifications and assumptions. Shop drawing review duration, delegated design, crane access, laydown area, sequence, who supplies anchor bolts.
5. Unit prices for the likely adds, so a change order is a lookup rather than an argument.

Price your markup on top of a cost you can defend line by line, and keep the takeoff that produced the tonnage. When the GC calls to level, the sub who can open the takeoff and show which sheet a quantity came from wins the conversation.

Where this fits

If you are on the other side of the table, leveling steel bids as the GC rather than submitting one, the same scope gaps read from the opposite seat. If you are running the takeoff itself, Ruh reads the drawing set, measures the frame, and prices the quantities against your own price book, with every line traceable back to the sheet it came from, which is exactly what you need when a GC questions your tonnage.