Large-opening winter guide
Warm panoramic sliding doors for winter terraces.
A winter-terrace sliding door must control heat transfer and air leakage while carrying a large glass leaf. The selection therefore joins thermal design, leaf weight, rollers, locking, compression seals, threshold drainage and the installation junction.
What to specify first
Send the clear opening, overall frame size, number of leaves, glass build-up, design wind, indoor and outdoor temperatures, sill detail and accessibility requirement. Those inputs determine whether a proposed warm sliding system is structurally and thermally relevant to the project.
Why sliding-door results vary.
A large glazed area can lower centre-of-panel heat loss when good insulated glass is used, yet the long perimeter increases the importance of spacers, seals and installation. Sliding hardware must maintain alignment and closing pressure as leaf mass and temperature change.
A quoted Uw must identify the tested or calculated door size and glass. A smaller reference unit, different sill or different number of leaves can change the result.
Selection checklist for a winter terrace.
Review the complete opening before choosing the profile. The same system can require different glass, rollers, locking points, sill treatment and reinforcement at different dimensions.
- Opening dimensions, panel arrangement and daily operating pattern.
- Glass thickness, insulated-glass make-up and calculated leaf mass.
- Compression-seal path, locking points and hardware temperature range.
- Threshold height, drainage, snow exposure and accessible-route needs.
- Perimeter fixing, insulation continuity and interior condensation check.
FDTL140 reference.
FDTL140 is a 140 mm full-FRP side-press sliding system. The leaf slides horizontally and is pressed against the seals at the end of closing. The source catalogue lists a maximum leaf mass of 200 kg and Uw 1.02 W/(m²·K) for an identified configuration; each ordered opening still requires hardware, glass, drainage and installation review.
| Input | Why it matters | Release record |
|---|---|---|
| Leaf mass | Roller and profile loading | Glass calculation and hardware schedule |
| Closing pressure | Airtightness around the perimeter | Seal and lock adjustment criteria |
| Sill | Water removal and surface temperature | Drainage and installation detail |
| Door Uw | Project energy and comfort | Size, glass, spacer and calculation scope |
Frequently asked questions.
Can a panoramic sliding door be used on a heated winter terrace?
Yes when the complete door, glass, seals, sill and installation meet the project thermal, air, water and structural requirements. A product name alone is not enough.
What makes a sliding door warm?
Whole-door Uw, insulated glass, warm-edge spacer, frame construction, perimeter seals, closing pressure and an insulated installation junction work together.
How is maximum sliding-leaf size determined?
The glass and sash mass, profile deflection, hardware capacity, wind load, aspect ratio and operating force are checked for the actual opening.
Define the door and supply route.
FDTL140 sliding door
Review the 140 mm full-FRP system, 200 kg reference and performance scope.
OpenSevere-cold verification
Add low-temperature deformation and air-leakage checks where the project requires them.
OpenProfiles and glass-free CKD
Choose the fabrication responsibility split for a pilot or project batch.
Open