# Commercial Plumbing Contractor Selection > Licensing, self-performed scope, manpower and bid clarity: what St. Louis GCs and owners should verify before hiring a commercial plumbing contractor. Canonical: https://legacyplumbingmo.com/resources/how-to-choose-a-commercial-plumbing-contractor-in-st-louis Last updated: 2026-02-10 [Resources](https://legacyplumbingmo.com/resources) Hiring & Bidding Licensing, self-performed scope, manpower, and bid clarity — the five things St. Louis general contractors and facility owners should verify before awarding a commercial plumbing contract. February 10, 2026 6 min read Written and reviewed by the Legacy Plumbing field & estimating team Last reviewed: October 2026 · Legacy Plumbing is a union commercial plumbing contractor serving St. Louis since 1996. Picking a commercial plumbing contractor in St. Louis is not the same as calling a residential plumber with a bigger truck. The wrong pick shows up as missed underground dates, failed inspections, and change orders nobody budgeted. Here is what to verify before you award the work. Related service: [Commercial New Construction Plumbing](https://legacyplumbingmo.com/services/new-construction) ## 1. Confirm licensing in the jurisdiction you're building in St. Louis City, St. Louis County, [St. Charles County](https://legacyplumbingmo.com/locations/st-charles-county) , and [Jefferson County](https://legacyplumbingmo.com/locations/jefferson-county) each have their own permitting and inspection process. Ask which entity holds the master license, who pulls the permit, and whether the contractor has passed inspection in that jurisdiction recently. A contractor who routes permits through a third party adds a delay you will feel at rough-in. ## 2. Ask what they self-perform Every scope that gets subbed out is a schedule handoff. Ask specifically about underground [site utilities](https://legacyplumbingmo.com/commercial/underground-site-utilities) and [medical gas](https://legacyplumbingmo.com/services/medical-gas) . - Underground sanitary, storm, water service, and grease waste — is excavation in-house? - Medical gas brazing — are the brazers ASSE 6010 certified on staff? - Backflow certification testing — in-house or subbed? - Camera inspection and drain cleaning for existing buildings ## 3. Look at manpower, not just the bid number A low number means nothing if the crew cannot be on site when the slab is ready. Ask how many journeymen the contractor can put on your job and where those people come from. Union signatory contractors in St. Louis can draw from [UA Local 562](https://legacyplumbingmo.com/union-plumbing-contractor-st-louis) when a [general contractor](https://legacyplumbingmo.com/general-contractors) compresses the schedule; non-signatory shops are limited to who they already employ. ## 4. Read the bid for exclusions The cheapest bid is usually the one with the most exclusions. Compare scope line by line: trenching and backfill, core drilling, fixture furnish versus install, temporary water, testing and certification documentation, and final inspection coordination. A clear bid that costs more is often the cheaper job. ## 5. Check the project history that matches your building A contractor who builds warehouses is not automatically the right pick for a dental suite. Ask for St. Louis metro projects of similar type and size, and call the general contractor who ran them. ## What to send when you request a bid Drawings or a written scope, the target schedule, and the jurisdiction. That is enough for a real number. Legacy Plumbing returns commercial bids in the St. Louis metro within one business day. ## Related services & projects - [Service areas](https://legacyplumbingmo.com/service-areas) - [Middle School Renovation in St. Charles (St. Charles, MO)](https://legacyplumbingmo.com/projects/middle-school-renovation-st-charles-mo) - [Retail Plumbing in South St. Louis County (St. Louis, South St. Louis County)](https://legacyplumbingmo.com/projects/retail-building-plumbing-south-st-louis-county) - [Ground-Up Site Utilities (O'Fallon, MO)](https://legacyplumbingmo.com/projects/ground-up-site-utilities-ofallon-mo) - [Cold Storage Facility in Foristell (Foristell, MO)](https://legacyplumbingmo.com/projects/cold-storage-facility-foristell-mo) - [What to Include in a Plumbing Bid Invite to Get Accurate, Comparable Numbers](https://legacyplumbingmo.com/resources/what-to-include-in-a-plumbing-bid-invite) Service Area Commercial Plumbing in St. Louis, MO See local coverage ## Talk to a St. Louis commercial plumber Send drawings or a scope and we'll return a written bid within one business day. [636-978-0120](tel:+16369780120) [Contact Us](https://legacyplumbingmo.com/contact-us) ## More Resources - [How to Choose a Commercial Plumbing Company in St. Louis](https://legacyplumbingmo.com/resources/how-to-choose-a-commercial-plumbing-company-st-louis) What facility managers, GCs and owners should check before hiring a commercial plumber in St. Louis — licensing, union labor, service capacity, safety and pricing. - [Commercial Hydro Jetting vs. Drain Snaking: Which Does Your Building Need?](https://legacyplumbingmo.com/resources/commercial-hydro-jetting-vs-snaking-st-louis) When to hydro jet commercial drain lines in St. Louis instead of snaking them — grease, scale and roots, how often to jet, and what a camera inspection adds. - [Commercial Water Heater Replacement in St. Charles County: A Planning Guide](https://legacyplumbingmo.com/resources/commercial-water-heater-replacement-st-charles-county) Planning a commercial water heater replacement in St. Charles or St. Louis? Signs it's time, tank vs. tankless, sizing, permits, and how to avoid downtime. ## Need a Plumber in St. Louis or the Surrounding Area? Written bids within one business day, scheduled service Monday–Friday 7am–4pm, and union-trained crews since 1996 across the St. Louis metro and a 2-hour radius. [Get Free Estimate](https://legacyplumbingmo.com/contact-us) [636-978-0120](tel:+16369780120) ## Related - [Contact Legacy Plumbing](https://legacyplumbingmo.com/contact-us) - [Company facts](https://legacyplumbingmo.com/company-facts) - [All pages (llms.txt)](https://legacyplumbingmo.com/llms.txt)