Concrete bids are sensitive to quantities and conditions. Slab thickness, reinforcing, vapor retarder, finish tolerances and weather all move the number, and each bidder may have assumed something different.
Watch who furnishes and who installs: rebar and embeds are often furnished by one party and installed by another, and excavation and backfill may or may not be in the concrete bid.
Typical scope items
What a complete concrete bid usually prices, and what to check in each:
| Scope item | What to check |
|---|---|
| Footings and foundation walls | Formwork, placement and stripping, to the drawings. |
| Slab on grade | Thickness, granular base, vapor retarder, reinforcing and finish. Each one is a place bids differ. |
| Elevated slabs and slabs on metal deck | Placement and finishing on the deck the steel contractor installs. |
| Reinforcing steel | Furnished and installed, installed only, or excluded and bid by a rebar subcontractor. |
| Finishing, curing and joints | Flatness requirements, curing method, sawcut joints and joint filler. |
| Embeds and anchor bolts | Usually furnished by others and set by concrete. Confirm both halves are carried. |
| Pumping and placing equipment | Often included, sometimes excluded or priced per pour. |
| Site concrete | Sidewalks, curbs, pads and dumpster enclosures may be in this package or in sitework. |
Common exclusions and qualifications
Not every exclusion is a problem. Some are fair because the work belongs elsewhere. The ones below are where concrete bids most often differ, so read them against the other bidders.
| Often excluded | Why it matters |
|---|---|
| Excavation and backfill | Often by the sitework contractor. A frequent gap at footings. |
| Reinforcing steel | If one bid includes rebar and another does not, adjust before comparing. |
| Cold or hot weather protection | Winter heat, blankets and admixtures are commonly excluded or qualified. |
| Testing and inspection | Normally hired by the owner. Usually a fair exclusion. |
| Vapor retarder | Sometimes excluded or a different product than specified. |
| Layout and survey | Check who establishes control lines and elevations. |
| Sealers, hardeners and polished finishes | Often excluded or offered as alternates. |
Alternates to watch
- Polished concrete finish
- Fiber reinforcement in lieu of welded wire mesh
- Added slab thickness or higher strength mix
- Sealer or densifier added to the base finish
Line alternates up by the numbers on your bid form, keep add and deduct straight, and treat an unpriced alternate as a question, never as zero.
Unit prices and allowances to compare
- Additional concrete, per cubic yard
- Slab on grade, per square foot
- Curb, per linear foot
- Undercut and replacement of unsuitable soil, per cubic yard
Compare rates only where the units match, and note any quantity already included in the base bid.
Where concrete meets other trades
Gaps and double counts happen at the edges. Read these packages together:
- Sitework (excavation, backfill, site concrete)
- Rebar subcontractor (furnish and install)
- Structural steel (embeds, anchor bolts, deck)
- Electrical and plumbing (pads, sleeves, under-slab work)
How Bidtab lays out concrete bids
Upload each bidder's PDF to one project for the package. Bidtab reads every bid and shows, side by side and in the order you uploaded them:
- each base bid, as stated;
- alternates aligned by number and description, with add or deduct for each bidder;
- a scope row for each item the bids address, with every bidder marked Included, Excluded, Qualified or Not stated;
- allowances and unit prices, with their units;
- each bidder's exclusions and qualifications as written;
- open questions where a bid is silent on an item other bidders addressed, where a figure isn't printed on the page it came from, or where line items don't add up to the total.
Every figure shows the page and words it came from, and the whole comparison exports to an Excel workbook. Bidtab doesn't rank bidders or price excluded scope; those calls stay with you. See the sample project (a roofing package) for the layout.