Thermally-Broken Aluminum Sill Extrusion

Thermally-Broken Aluminum Sill Extrusion

This proprietary 6063-T5 aluminum sill extrusion incorporates a factory-installed polyamide thermal break strut to interrupt the conductive aluminum path between interior and exterior sill faces — reducing condensation risk and thermal bridging at the critical sill condition where water management is most demanding. Designed for use across the full Blomberg T450N and T600N system line, it is the sill extrusion that the system was engineered around.

The extrusion features a sloped exterior face for positive drainage, an integrated weep slot pattern at 12" centers for reliable water evacuation, and a snap-in flush sill cover/threshold trim channel for a finished interior appearance. Available in standard 6', 8', and 12' lengths with Class 1 anodize in any standard RAL color — factory-cut to project length on request.

At a Santa Barbara coastal residence, it's the sill extrusion that keeps the water out, the heat in, and the interior floor finish dry — year after year, storm after storm.

Studio View — 24" Isometric Section with Callout Labels

A 24" cut section of the sill extrusion in isometric view, with callout lines labeling the polyamide thermal break strut, the weep slots at 12" centers along the exterior face, and the snap-in flush sill cover channel at the top. The sloped exterior drainage face is visible in the extrusion profile.

Installation — Santa Barbara Luxury Residential Construction Site

A Blomberg-certified glazing contractor installing the sill extrusion into a first-floor T450N rough opening at a luxury Santa Barbara modern residence. The stucco framing surrounds the opening, and the Pacific coastal landscape stretches beyond the open wall — the kind of project where the sill extrusion has to perform as well as the view.

Polyamide Thermal Break Cross-Section — Magnification Detail

The polyamide thermal break strut in the sill extrusion cross-section under magnification, showing the precision polyamide insert bonded to the aluminum flanges on both sides and the thermal isolation gap between interior and exterior aluminum faces. The polyamide insert is the engineering core of the sill's thermal performance — the same material and bonding process used in the T450N and T600N sash and frame profiles.

Specifications

Trim Channel: Snap-in flush sill cover/threshold trim included  |  Manufacturing: Blomberg Windows, Sacramento, CA, USA  |  Price shown: Per 6' length — select length at checkout