How to bid drywall work as a subcontractor

What you are actually bidding

Settle the boundary before you measure anything. What everyone calls "the drywall package" is a stack of separate specification sections, and the seams between them are where a drywall sub loses money:

• Non-structural metal framing, 09 22 16. Partition studs and track, furring at walls and columns, framing for gypsum ceilings, soffits and bulkheads.
• Gypsum board, 09 29 00, plus the assembly-level section 09 21 16 Gypsum Board Assemblies, where wall types appear as tested systems rather than as loose material. Which boards you owe is a spec question, not a habit. See drywall types for how type X, moisture resistant, abuse resistant and shaft liner differ.
• Cold-formed metal framing, 05 40 00. Load-bearing and exterior heavy-gauge framing. Sometimes yours, often the steel or exterior package. Structural metal studs are a different product, a different gauge and a different labour rate than a partition stud.
• Acoustic insulation, 09 81 00, or thermal insulation, 07 21 00. Which section the partition batt insulation sits under is usually what decides whether you install it or the insulation sub does. When neither section is clear, nobody has carried it.
• Acoustical ceilings, 09 51 00. Grid and tile normally belong to another sub, but the boundary between an acoustical ceiling and your drywall ceilings, soffits and bulkheads is drawn on the same sheet, so you have to read it anyway.
• Firestopping, 07 84 00. Penetrations and head-of-wall joints at rated assemblies.

Two more boundaries are worth naming in writing: whether you carry in-wall backing and blocking for other trades, and whether patching after mechanical, electrical and plumbing rough-in and trim is in your number or a separate line. Silence on either one reads as inclusion.

Read the drawings for your sheets

The set is large and your scope is concentrated in a handful of places.

• The partition plan gives you location and length. That is all it gives you.
• The wall type legend governs. It carries stud width, gauge, spacing, board type, number of layers per face, insulation, and the small elevation diagram that says where the wall stops. When the plan and the legend disagree, the legend is the assembly and the plan is only the location. Take off by wall type, never by wall.
• The reflected ceiling plan carries every ceiling, soffit and bulkhead. Hatch patterns separate gypsum ceilings from grid. None of your ceiling scope is on the floor plan.
• Interior elevations and details carry reveals, trim conditions, furred columns, shaft wall sections and the backing you are expected to install.
• The finish schedule and the painting specification carry the level of finish. It is frequently not in your section at all, which is exactly why it gets missed.
• The rated assembly listings. Each rated wall type calls a tested design number. That listing, not your standard detail, fixes stud gauge, screw spacing, layer count, joint treatment and the head-of-wall condition.
• Other disciplines you must read. Mechanical and plumbing plans, for shafts, chases and duct sizes that will not actually fit the chase as drawn. Structural sheets, for deck profile and the deflection allowance at the top of full-height walls. The door and frame schedule, because frame throat depth has to match your wall thickness and a mismatch is your problem in the field.

Getting the quantities right

Drywall is bid in square feet of board and linear feet of track, with counts for openings and per-lf quantities for trim. The trap is that neither of the two main numbers equals wall area.

• Count both faces, by type. One layer each side of a partition is two square feet of board per square foot of wall. Two layers each side is four. A shaft wall is a liner panel on the shaft side plus layers on the accessible face. Board sf and wall sf are different quantities and mixing them is the single most common takeoff error in this trade.
• Framing height is not board height. Full-height and rated partitions frame to the underside of deck while board may stop a set distance above the finished ceiling on one or both faces. That distinction lives in a small diagram in the legend, not in a number anywhere. Pricing wall length times ceiling height understates framing and overstates board at the same time.
• Shaft walls look like ordinary partitions in plan. Elevator hoistways, duct shafts and stair pressurisation shafts are drawn as two parallel lines like everything else, but they are a different assembly, built from one side, and they price materially higher per square foot. Find them on the core plan and the shaft sections before you find them in the field.
• Openings. Doors, borrowed lights and storefront openings remove board but add framing and trim labour. Set a deduction threshold from your own production history rather than a rule of thumb, and say in the proposal how you handled it.
• Per-lf items are not rounding. Corner bead, casing bead, control joints, acoustical sealant (usually two beads on both faces at rated and acoustically rated partitions), deflection track, and the tested head-of-wall joint detail at every rated wall.
• In-wall blocking and backing. Grab bars, wall hung fixtures, handrails, monitors, casework and toilet accessories all need backing, and it is drawn on interior elevations and accessory details rather than on the partition plan. If the spec puts backing in your section, you are carrying dozens of small pieces nobody counted.
• Finish level applies to the whole board area. A level 5 finish is a skim coat over every square foot, so the delta against level 4 is labour and material across the entire surface, not one line item. Price the levels separately by area, and if the documents never state a level, say in writing which one you carried.

The practitioner detail that separates a real drywall estimate from a spreadsheet: board length is an estimating decision, not a field decision. On a wall running nine and a half feet to the underside of deck, ten-foot board hung vertically gives you no butt joints, while eight-foot board plus a strip gives you a butt joint in every stud bay. Butt joints are the slowest thing a taper does and they are where finish complaints start. Decide the board size, carry the joint count that follows from it, and build your finishing labour on that instead of on a flat rate per square foot.

What the GC checks when leveling drywall bids

Bid leveling is the GC normalising every proposal to one scope. Expect them to check, in roughly this order:

• Board square footage carried, against the other bidders. An outlier gets a phone call, and a sub who cannot show which wall types produced the number loses on credibility, not price.
• Which wall types you priced, and whether you caught the rated and shaft assemblies.
• Framing height, deck to deck or to above ceiling only.
• Level of finish, by area, and whether level 5 is priced anywhere.
• Insulation in or out. This is the most reliable scope gap in the trade.
• Ceilings. Drywall ceilings and soffits in, grid and tile out, stated explicitly.
• Firestopping and head-of-wall joints, in or out.
• Backing, blocking and patching.
• Allowances you carried, and for what.
• Unit prices, so they can price scope movement without re-bidding.

Structure the proposal

Five parts, in this order.

1. The number, with the board square footage and the spec sections it covers.
2. Inclusions, as items, by wall type and by area.
3. Exclusions, listed the same way. This is the most valuable section in the document.
4. Clarifications and assumptions. Level of finish assumed, framing heights assumed, insulation, firestopping, backing, patching trips, access and hoisting, temporary protection, and whether layout is yours.
5. Unit prices for the predictable adds: sf of board by wall type, sf of level 5, lf of soffit, ea of backing, and an hourly rate for patch and repair work.

Put your markup on a cost you can defend line by line, and keep the takeoff that produced it. Anything you leave silent gets filled in with an assumption, and the assumption will not favour you.

Where this fits

Drywall is the trade where the drawings understate the scope most consistently, because the information that drives cost is split across a legend, a schedule, a ceiling plan and a spec section written by someone else. If you are running the takeoff, Ruh reads the drawing set, measures the scope by wall type, and prices the measured quantities against your own price book, with every line traceable back to the sheet it came from. That is what you need in hand when a GC calls to question your square footage.