A window sub for a Twin Cities builder should do three things: hit the date, flash and seal every opening the same way, and close out clean. JMB Builders runs the scope full-service or labor-only, locks lead times at contract, photographs every opening's flashing, and closes punch items the same week. Here is how it runs from takeoff to punch list.
It applies to new construction sets with the WRB, and to replacement and insurance scopes on renovation work, including full-frame openings that need rebuilding.
Two ways to hire us: full-service or labor-only
Full-service: we take off the window schedule from your plans, verify rough openings on site, order, receive and stage, and install. You get one line item and one contact. We install every brand and are not a dealer for any of them, so the product is whatever the schedule calls for.
Labor-only: your account, your order, your delivery. Our crew sets, shims, fastens, flashes, foams and seals. This suits builders with their own supplier pricing who need dependable labor that treats the openings right.
What happens before framing finishes?
The scope succeeds or fails weeks before install day. The pre-work checklist with your PM:
- 1Plan takeoff and window schedule review, flagging egress, tempered-glass locations and anything that will not pass inspection as drawn.
- 2Glass and ratings check against the energy compliance path: whole-window U-factor and SHGC on the schedule match what the plans were approved with, so the inspector's NFRC labels match the paperwork.
- 3Lead-time lock. Stock vinyl lines run a few weeks; custom colors, fiberglass and clad wood commonly run two months or more, and busy season stretches all of it. We get the manufacturer's current lead time in writing and back-plan the order from your framing schedule.
- 4Rough-opening verification on site once walls are up. Catching a wrong RO before the order ships beats arguing about it after.
- 5Delivery staging: where units land, who receives them and how they are protected until set.
How does each opening get flashed and sealed?
Every opening gets the same sequence regardless of schedule pressure:
- 1WRB cut and folded at the opening, sill flap in, head flap taped up out of the way.
- 2Sill pan: a rigid pan or flexible sill flashing with back dam and end dams, so any water that gets past the fin drains out over the WRB.
- 3Unit set plumb, level and square, shimmed at the fastening points and checked for reveal and operation before the last fastener goes in.
- 4Jamb flashing over the nail fin, then head flashing lapped under the WRB head flap. Head flashing goes over the wrap, never behind it. That detail is what separates a dry wall from a spring callback.
- 5Low-expansion foam at the interior perimeter, filling the rough-opening gap without bowing the frame.
- 6Interior air seal: backer rod and sealant or an air-barrier tape from frame to framing, so the foam is not the only thing stopping air.
Why do we foam and seal, not just set?
The NFRC label on a window rates the unit alone. Nothing on it accounts for the gap between the frame and the rough opening, and a quarter-inch gap left empty around a whole house of windows leaks more air than the windows themselves. On a spec home that is a blower-door number and a warranty call about a drafty bedroom. On a custom home it is a homeowner who paid for U-0.22 triple-pane and feels a draft at the casing.
So the perimeter is part of our set, not something the insulators pick up later. Low-expansion foam fills the gap; the interior edge gets a continuous seal to the framing. Openings are photographed at each stage, and the taped flashing in the photo above is that sequence. If your envelope consultant or super wants documentation, it already exists.
How do scheduling and closeout work?
You get a named lead on every job, a realistic crew-day count at bid time, and a call the moment anything threatens a date: weather, freight damage, a backorder. Surprises are what builders fire subs over. The phone call is part of the scope.
Closeout means every unit operated and locked, screens in, labels off except the NFRC stickers your inspector needs, openings foamed and sealed and ready for drywall, and debris gone. Punch items close the same week.
How is it priced, and how do you start?
Labor-only is priced per opening and moves with unit size, floor height and flashing spec. Full-service bundles supply and install per the window schedule. Either way you get a written scope with inclusions and exclusions spelled out, the same discipline we ask homeowners to demand when they compare quotes. Trim-out after the set is its own line, and painting or staining that trim is its own line too.
If a project goes to frame this season anywhere in the Twin Cities metro, send the window schedule, or three photos of the openings on a renovation, and you hear back from us within one business day: jmbbuildersmn@gmail.com.
What JMB Builders does
JMB Builders is a licensed Minnesota residential building contractor (BC809005) based in Zimmerman, working across the Twin Cities metro. One crew, one named lead. Paid by check or direct deposit. Call 763-204-2099 (text) or send the schedule through the site.
- Window installation crew for new construction — jmbbuildersmn.com/services/builders/window-installation-crew-new-construction
- Trim-out partner for window companies — jmbbuildersmn.com/services/builders/window-company-trim-out-partner
- New construction trim-out package — jmbbuildersmn.com/services/builders/new-construction-trim-out-package
- All contractor services — jmbbuildersmn.com/services/contractors
Frequently asked questions
Do you handle both new construction and replacement scopes for builders?
Yes. New construction sets with full flashing integration into the WRB, and replacement scopes on renovation and insurance projects, including full-frame work where the opening has to be rebuilt. The sill pan, flashing, foam and interior seal sequence is the same on both.
Can you work from our supplier's window package?
Yes. Labor-only is a core service, and many builders have their own supplier accounts. We will review the schedule before you order if you want a second set of eyes on ROs, egress, tempered locations and the U-factor and SHGC against the energy compliance path.
How far ahead do you book?
It depends on the season. Summer slots fill several weeks out. Winter is more flexible. Call with your framing date and you get a straight answer on what is real. We would rather turn down a date than miss one.
Are your crews licensed and insured for GC requirements?
JMB Builders is a licensed Minnesota residential building contractor, and the license number is on every bid. Certificates for your onboarding file are available on request. Fall protection on multi-story sets is standard practice, not a negotiation item.
Do you trim out the windows after they are set?
Yes, as its own line on the scope. Jamb extensions, casing, stool and apron, or drywall returns, paint-grade or stain-grade. It can be the same crew that set the windows, which keeps the reveals consistent. Painting is quoted as a separate line, or leave it primed and caulked for your painter.
Do you take storm and insurance repair work from GCs?
Yes. Hail-damaged window trim, fascia and siding, and window replacements on insurance claims. Send the adjuster's scope and three photos of the damage and you hear back from us within one business day. The paperwork matches the adjuster's line items so the claim reconciles.