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Commercial · General ContractorsHVAC Subcontractor for General Contractors
An HVAC subcontractor for general contractors has three jobs that should not need chasing: qualify before the bid, build to the Division 23 drawings on your schedule, and hand over a complete close-out package. ZK Mechanical prices commercial mechanical work for GCs across Burlington, Oakville, Milton, Hamilton and Mississauga, with TSSA-licensed gas technicians on the gas scope. Send the drawings, the specification and the addenda, and you receive a written price with inclusions and exclusions listed.
Before a GC carries a mechanical contractor's number, the paperwork has to be in hand. The usual pre-qualification list is a current WSIB clearance certificate, a certificate of liability insurance naming the GC and owner as additional insureds, the firm's TSSA contractor registration for gas work, and a written health and safety policy. For roof work, most constructors also ask for Working at Heights training records. Ask for our package when you send the tender documents, so it is on file before the subcontract is drafted.
We price what is drawn. The bid follows the Division 23 drawings and specification sections as issued, including addenda, and the bid letter names the items that fall between trades: who supplies and flashes roof curbs, who runs line-voltage power and disconnects, who pays utility charges for the gas meter, who cuts, patches and fire-stops. Scope gaps between divisions are where change orders come from. Naming them at tender costs nothing and saves an argument in month three.
Once awarded, the order of work is submittals, release, rough-in, set, start-up. Shop drawings and equipment submittals go to the consultant early, because rooftop units and make-up air units are built to order and nothing is released until they come back reviewed. On site we coordinate with the electrical contractor, whose connections fall under an ESA permit, with the roofer for curbs and penetrations, and with the sprinkler and framing trades for duct routes. Rough-in is finished ahead of the ceiling grid and board, which is the milestone your schedule cares about.
Close-out is a deliverable, not an afterthought. The package holds operation and maintenance manuals, a start-up sheet for every unit, the air balance report, red-lined as-built drawings, a warranty letter with start dates, and the inspection records: the building inspector's mechanical sign-off, gas pressure-test documentation and any TSSA approval the equipment required. Progress billing follows a schedule of values, with holdback handled under the Construction Act.
Our work for GCs is small and mid-size commercial: plaza units, tenant improvements, restaurants, industrial condos and stand-alone buildings, plus new construction HVAC on the residential side. Where a project has no mechanical drawings, we can carry the design under commercial HVAC design-build. The commercial HVAC page lists the equipment we install; send tender documents here with the closing date in the subject line.
Equipment we install and service
Packaged gas-electric and heat pump rooftop units, commercial split systems and ductless units, received, hoisted, set on curbs and connected. Crane booking and the lift plan are normally carried in the mechanical price, and the street or lot closure is coordinated through your site superintendent.
Supply, return and exhaust ductwork fabricated to the drawings, insulated where specified, with diffusers, grilles, fire dampers and access doors installed before close-in. Duct routes are checked against structure and sprinkler mains before fabrication, not after.
Gas distribution from the meter to each appliance, pressure tested and tagged by TSSA-licensed technicians, plus unit heaters, infrared tube heaters and gas-fired make-up air units with their venting and interlocks.
Washroom and general exhaust fans, energy recovery ventilators, thermostats and low-voltage control wiring. Building automation programming, where specified, is carried by the controls contractor named in the specification and we coordinate points with them.
What goes wrong in these buildings
- My mechanical sub went quiet the week the rooftop units were supposed to land.
- The mechanical price came in as one line with no inclusions, and the change orders started in week two.
- Occupancy is Friday and I still do not have the air balance report.
- The consultant rejected the shop drawings twice and nobody told me until the equipment was late.
- The roofer and the mechanical contractor each say the curb flashing is the other one's scope.
- I cannot issue the subcontract until I have a WSIB clearance and an insurance certificate.
How it works
Send drawings, specifications, addenda, the closing date and your pre-qualification form. You get the compliance documents and a bid letter that states what is carried, what is excluded and which alternates or separate prices were requested.
Submittals are logged with dates so late reviews are visible early. We attend site meetings, mark up coordination drawings with the other trades, and complete rough-in and the gas pressure test before the ceiling closes.
Each unit is started with readings recorded, the system is balanced to design airflow, deficiencies from the consultant's review are cleared, and the close-out package is delivered in the format the specification asks for.
Common questions
What do you need from us to price a job?
The mechanical drawings and Division 23 specification, architectural plans and reflected ceiling plans for duct routes, roof and structural drawings where units are being set, all addenda, the closing date and your schedule. If the electrical drawings are available we check that power is shown for every piece of mechanical equipment, since missing feeds are a common coordination gap.
Who carries the roof openings, curbs and electrical connections?
The bid letter states it line by line. The usual split has the mechanical trade supplying and setting the roof curbs with the units, while cutting the deck, framing the opening and flashing the curb stay with the roofer and framer, and power wiring and disconnects stay with the electrical contractor. If you want any of that carried in the mechanical number, say so at tender and it is priced separately.
Do you take design-build work when there are no mechanical drawings?
Yes, for small buildings. The mechanical design is prepared by a qualified designer, BCIN-registered or a professional engineer depending on the building's size and occupancy, and we give you one price for design, permit drawings and installation. On larger projects where the owner has an engineer, we price the engineer's documents as issued.
What is in your close-out package?
Operation and maintenance manuals for every piece of equipment, start-up sheets with recorded readings, the air balance report, as-built drawings, a warranty letter stating start and end dates, gas pressure-test records and copies of inspection sign-offs. It is assembled as the job progresses so it can be handed over at substantial performance, not weeks afterward.
Related
Keep the building running.
One licensed team for installs, maintenance contracts and 2 AM calls.