Mr-Glass Home Additions & ADU Nationwide

Mr-Glass Home Additions & ADU: The Santa Clara Owner’s Guide

Mr-Glass home additions and ADU systems in Santa Clara typically run $45,000-$130,000 installed, depending on whether you’re extending an existing structure or building a detached unit from slab to roof. We stock Mr-Glass-compatible framing hardware, glazing channels, and weather-seal components for same-day replacement on most standard series. Most Santa Clara owners discover a problem when they notice water intrusion at the glass-to-frame junction or feel drafts where the thermal break should be performing.

Call (669) 259-1843

Which Mr-Glass Models This Applies To

Mr-Glass produces three primary series for residential additions: the 400 Series aluminum framing, the 600 Series thermally broken aluminum, and the 800 Series structural silicone-glazed system. The 400 Series uses a snap-in glazing bead with a 5/16-inch bite depth, while the 600 and 800 series share a 3/8-inch dual-durometer EPDM gasket system that is not interchangeable. Check the etched mark in the frame extrusion, usually visible on the interior face near the head jamb, or measure the glazing pocket width with a caliper if the label has worn off.

OEM Mr-Glass gaskets and pressure plates are available through their distribution network with a 2-3 week lead time. We stock quality aftermarket equivalents from Tremco and Dow Corning that match the Shore A hardness and UV-stabilization specs of the originals, and we warranty the installation regardless of which source we use. The compatibility gotcha in Santa Clara’s climate is the gasket compound: standard EPDM hardens faster than the silicone-blend formulations, so we specify the latter for any unit within three miles of the bay where salt air accelerates degradation.

Signs Your Mr-Glass Home Additions & ADU Is Failing

• Condensation between panes in the insulated glass unit (IGU). The desiccant in the spacer bar has saturated, which means the edge seal has failed. In Santa Clara, this usually shows up first on south-facing elevations where daily thermal cycling is most extreme.
• Draft at the sill or head even with the sash fully closed. The pile weatherstrip has compressed past recovery or the frame has settled slightly out of square, breaking the compression seal. We see this often in additions built on post-tension slabs that have experienced minor deflection.
• Visible daylight between the glass edge and the glazing pocket. The structural silicone or tape gasket has debonded from the frame, which compromises both weather resistance and the structural retention of the glass. This is not a cosmetic issue; it’s a safety concern if the unit is above ground level.
• Excessive frame sweating on the interior during Santa Clara’s winter mornings. The thermal break in the aluminum extrusion has lost integrity, allowing exterior cold to conduct directly to the interior surface. The 600 Series is particularly susceptible if the polyamide strip was nicked during original installation.
• Hardware operation growing stiff or noisy. The stainless steel rollers or hinges are corroding, usually from condensation runoff that pools in the track rather than draining through the weep holes. We clear and verify those drainage paths on every service call.

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Replacement Cost & What’s Included

The range depends on unit size, access difficulty (second-story work requires scaffolding), and whether the original installation used proper sill pan flashing that we need to preserve. Our quote is a flat written price with a written scope under Clause 1 of the Haven Standard, and every job includes a documented photo record of the condition we found and the work we performed. The 365-Day Done Right Promise covers the installation and materials.

DIY or Call Us?

There is one thing a Mr-Glass owner can safely check: verify that the weep holes at the sill are unobstructed and that the drainage plane below the unit is clear of debris. Use a piece of wire or a pipe cleaner, not compressed air, which can drive moisture deeper into the wall assembly.

Everything else warrants a professional. Removing an IGU without proper suction equipment risks breakage and serious laceration. Re-glazing with structural silicone requires surface preparation and cure time that cannot be rushed, and an improperly set unit will leak within the first winter. Thermal break work involves disassembling the frame extrusion, which disturbs the factory seal. We carry the Tremco and Dow Corning compounds calibrated to Mr-Glass specs on every truck, and we document the installation with photos you receive before we leave. Call (669) 259-1843 to schedule your free estimate.

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