A waterproofing bid reads clean on paper: below-grade membrane, dampproofing, insulation, all named against the wall sections and drawn in section detail. What the drawings don't settle is who supplies a flashing that masonry installs, who pays for a substrate that isn't cured enough to take a membrane on schedule, and who's on the hook for protecting a finished wall through a backfill sequence that runs longer than planned. None of that shows up as square footage, and all of it shows up as a claim later.
This is a working list of where those questions actually get decided, built from what shows up across real Canadian ICI tenders. Not a systems catalogue — a list of the specific clauses worth hunting down before the number leaves the office.
What's reliably yours
- Below-grade waterproofing, complete — sheet or fluid-applied systems on foundation walls and slabs, with protection board, drainage composite and terminations built to the detail. This is the core of the bid, and it's the one part every set of drawings actually shows in section.
- Dampproofing — the extents where the documents draw the line between dampproofing and true waterproofing. Extract which walls get which; the two systems price and perform completely differently, and specs mix the language more often than they should.
- Foamed-in-place insulation — spray-foam areas, thicknesses and types, closed-cell versus open-cell, plus any thermal barrier requirement over the foam and the air-barrier role it plays wherever the documents name it that way.
- Below-grade and perimeter insulation — rigid insulation on foundation walls and under slabs, wherever the documents assign it to this scope rather than to concrete or the general envelope package.
Where the fight actually happens
Air and vapour barrier systems — packaged here, or packaged with cladding?
The whole-building air barrier sometimes rides inside the waterproofing package and sometimes ships with cladding — and either answer is common enough that you can't assume. The real cost isn't the field of membrane itself; it's the transitions and tie-ins at every window, penetration and dissimilar-material interface, which is where the actual labour and the actual warranty exposure live. Extract the assignment explicitly rather than inferring it from which section the air barrier happens to be printed under.
Traffic and deck coatings — system and warranty, not just membrane type
Parking membranes, balcony coatings and hot rubberized asphalt decks are frequently priced by this trade, but they carry their own system names, their own warranty terms and often their own manufacturer certification requirement, separate from the below-grade system on the same job. Extract these with the specific system and warranty named rather than folding them into a generic membrane allowance — a traffic-rated deck coating and a foundation wall membrane are not interchangeable line items even when the same trade installs both.
Through-wall and cavity flashings — supply and install split, and often nobody has supply
Membrane through-wall flashings in masonry and cavity wall assemblies split cleanly by verb: masonry typically installs what waterproofing supplies. The trap, confirmed across real tenders, is that the supply side is frequently unowned by either trade — masonry assumes it arrives with the wall assembly, waterproofing assumes masonry orders its own flashing material. Extract who supplies and who builds in separately, per detail, rather than assuming the split is understood.
The other half: what isn't yours, even when it looks close
- Roofing membranes and roof insulation — the roofing trade's scope entirely, including its own vapour retarder. The material can look identical to a below-grade membrane; the trade line is drawn at the roof deck, not at the material spec.
- Batt insulation in framed walls — usually the drywall trade's. Worth recording the assignment explicitly even when it's obviously not yours, so the boundary is visible rather than assumed by everyone reading the same set.
- Waterstops in concrete joints — typically supplied and placed under the concrete trades, but extract who specifically, because real tenders disagree on this more often than the "typically" suggests.
Four things that hide outside the membrane spec
- Substrate acceptance and cure times. A 14 to 28 day concrete cure requirement before membrane application is a precondition that owns the schedule, not a footnote — confirm it against the actual pour dates before assuming the waterproofing crew can mobilize when the job plan says.
- Warranty and manufacturer oversight. Warranty terms, approved-applicator requirements, manufacturer site reviews and field adhesion testing all carry real cost and real schedule dependency, and they're routinely stated once, separate from the system spec itself.
- Termination and tie-in details. Terminations at grade, tie-ins to roofing and cladding, and detail conditions at every penetration — each drawn condition is its own piece of labour, not a rounding error on the overall membrane area.
- Backfill timing and protection. Who protects the finished membrane and exactly when backfill is permitted to proceed is a site-work coordination question with a real cost if the sequence runs long — see below.
Who you're actually sharing the envelope with
| Trade | What to reconcile before you price |
|---|---|
| Concrete & forming | Substrate finish quality, tie-hole treatment, kicker details and cure timing — all four decide whether the membrane can go on when the schedule says it can. |
| Site work | Backfill sequence and the handoff from your drainage board to their drainage pipe — confirm both ends of that connection are actually assigned to someone. |
| Roofing & cladding | Membrane tie-ins and air-barrier continuity at every interface where your system meets theirs — the failure point on most envelope warranty claims. |
| General contractor | Weather windows for application and who's responsible for protecting completed work once it's installed but not yet covered. |
The pass that catches most of this
Read the membrane spec for the system, then read Division 03 specifically for cure-time and substrate-acceptance language before assuming the schedule holds. Hunt the flashing details for supply-versus-install verbs rather than trusting that the split is obvious, and confirm the warranty and manufacturer-oversight clauses before pricing labour that assumes a certified applicator wasn't required. The membrane spec tells you the system; the clauses scattered outside it tell you what actually has to happen before that system can go on the wall.