As a gardener, you may reach a point where a couple of chairs on a patio isn’t enough. You have your space and your intentions, but the ever-changing weather hampers the outdoors. This is where a glass pergola is designed to help. It is a big investment, and so is the installation, but a glass pergola set in your garden will transform the space.
What Is a Glass Pergola?
A glass pergola is considered a permanent garden structure with a glazed, usually, aluminium framed glass roof. It is designed to attach to a house wall, or stand alone in the garden. A pergola is open-sided and has the option of being fitted with glass or polycarbonate panels on the sides, or some sort of enclosure like zip-blinds.
Glass is usually tempered or laminated for safety. Each system varies depending on the use of stepped glass panels, varying pitches of the glass, and others which may use a fully vaulted construction to aid in drainage.
Frame Construction
Aluminium is generally the material for framing because of its lightweight and strong support for spanning structures without needing support beams during construction. Aluminium is also able to withstand the test of time with no corrosion and minimal finish deterioration. Steel is heavier than aluminium and is typically more costly to maintain.
Rain management is a big concern on the roof of the structure. To manage this concern, there is a drain system designed for capturing rain and guiding it downward and away from the structure. The sections of this frame are designed to capture and guide rain to a lower element of the structure where it can be disposed of away from the structure.
Foundations
Foundations are typically the most overlooked concern when it comes to the construction of a freestanding structure. The foundation will be designed to withstand the lateral and vertical loading of the structure, including the load and resultant vector due to the wind. For structures that are attached to a building, a significant portion of the load will be transferred to the building and the structural support of the building will dictate where the fixings can be placed.
Design
Flat roofs offer a more modern aesthetic, while other roof designs like hip or gable are more popular for older designs. Roofs that are pitched are generally more effective for directing water away from the structure and are designed to be used on older properties. There are other designs like roof profiles that are more traditional for orangeries.
Louvred glass pergolas are different from other types of glass systems because unlike fixed glazing, roof panels can rotate. In closed position, it protects from the weather, but in the open position, it allows fresh air to circulate. Mechanisms can be manual or motorised. It is a proven flexible system compared with fixed-roof systems, and is especially valued during spring and autumn with unpredictable weather.
Integrated extras vary widely. LED lighting built into the frame, heating elements, retractable side screens, integrated speakers, and other options are widely available and can be considered, depending on the intended use of your glass system and how long you plan to use it during the year. There are other things that are often considered after the fact.
Condensation is rarely an issue with tempered glass, since glass has superior thermal insulative properties compared to older glazing, and a glass roof is more durable. In contrast, polycarbonate is more vulnerable to condensation and typically has a shorter lifespan, as it will yellow and become discoloured over time.
Most glass pergolas are considered permitted development, but planning permission can be necessary. This especially applies to things built above a certain size or systems that are inscribed on an older, listed building.
Maintenance of glass systems is straightforward, with a few exceptions. Oftentimes, cleaning the roof is unexpected. Since the glass is flat, debris building is more visible, compared to a pitched roof. Because of its flat and even structure, the surfaces are more prone to algae retention and need to be cleaned more than just a few times a year.
What it comes down to
It is true that a glass pergola is a structure that requires a significant investment, so purchasing one is a big decision. The construction quality for glass systems varies across the board, and the brochures seldom reveal the details that differentiate quality systems from budget ones. The differences show up in frame construction, drainage and how systems endure the winter. It is worth spending the time for a quality purchase.