Doors and windows from overseas factories.
Aluminum lift-and-slide doors, pivot doors, folding doors and tilt-and-turn windows made in China show up on more DMV job sites every year. Here is what we check so they pass inspection and keep working.
Why these projects need a different process
A U.S. dealer order comes with a local rep, a warranty desk and parts on a shelf. A direct factory order comes with a container. Nobody local is responsible for the product until someone installs it, and by then any mistake in size or spec is expensive to fix.
The factories are usually precise. They build exactly what the order says. Most of the problems we see start with the order itself.
1. Rough opening deductions
Factories manufacture to the exact unit dimension you give them. If you send the rough opening size instead of the unit size, the frame won't fit. Approve factory shop drawings that show the unit size, the rough opening, sub-frame details and sill drainage. Architectural elevations alone are not enough.
2. Safety glazing marks
Glass in doors, next to doors, near the floor and in wet areas must be tempered or laminated, with a permanent certification mark etched in the corner of each pane (ANSI Z97.1 / CPSC 16 CFR 1201, certified by SGCC or an equivalent body). No mark usually means a failed inspection, even if the glass really is tempered.
3. Energy code in climate zone 4A
Montgomery County, DC and Northern Virginia sit in IECC climate zone 4A. Under the 2021 IECC prescriptive path, windows and glazed doors need a U-factor of 0.30 or lower, and ENERGY STAR uses 0.27 for Maryland. Many custom factory profiles have no NFRC label, so ask the factory for tested or calculated values and the glass make-up. Local code adoption varies, so we confirm the requirement for your address.
4. Thermal breaks
Aluminum conducts heat. A frame without a thermal break sweats and can frost on the inside in winter. Ask for a polyamide thermal break (commonly specified as PA66 GF25) and a profile section drawing that shows it.
5. Hardware and spare parts
Rollers, multi-point locks, gaskets and handles are usually metric and brand-specific. Get the hardware brand in writing and order a spares kit with the shipment: rollers, gasket runs, a handle, keepers and a lock cylinder.
6. Crating and delivery
Glazed units should travel upright in braced wooden crates or on A-frames, never in loose cartons. On delivery, open the crates, photograph every unit and check glass marks and hardware count before signing for the freight.
7. The install details
Get the installation manual in English and confirm the sill pan, flashing tape and anchor pattern work with the frame. Heavy lift-and-slide panels need a crew and equipment sized for the weight.