Winter gazebos in Almaty

At first glance the difference between a glazed and a winter gazebo seems unclear. A glazed gazebo is a structure whose perimeter is closed with glass. It gives good protection from wind and driving rain, but in frost it stays cold inside, close to the outdoor temperature.

A winter gazebo is a more complex structure. On top of the glazing it adds an insulated shell, a vapour barrier and a heat source. Every winter gazebo is glazed, but not every glazed one is a winter gazebo. If the perimeter is glazed but the walls, floor and roof are not insulated, heating such a gazebo in freezing weather is pointless: the heat will escape through the enclosing structures.

Choosing between a cold and a warm shell should be based on how you plan to use the building. For a cup of tea in mild cool weather and protection from the wind, a glazed gazebo is enough. For proper relaxation in freezing weather you need an insulated gazebo with heating.

The basis of any warm gazebo is a properly assembled thermal envelope. This is exactly what sets winter gazebos apart from summer ones, not the thickness of the timber in the posts. All the surfaces separating the interior space from the outside must be insulated.

The walls of a winter gazebo are insulated with mineral wool of 35-50 kg per cubic metre density, with a layer thickness of 100 mm. The roof is insulated thicker than the walls, with a 150 mm layer, and this is justified: warm air rises, and a noticeable part of the heat escapes through an uninsulated ceiling. The floor is insulated with a 100 mm layer of mineral wool.

A typical mistake during construction is to insulate the walls but forget about the floor and roof. In such a gazebo your feet are cold even with the heater running, and condensation forms on the cold ceiling. If the frame is steel, the posts freeze right through: they are covered with cladding and insulation so that thermal bridges do not negate the whole thermal envelope.

In a winter gazebo design the vapour-barrier section is often underestimated, and this is exactly where critical mistakes are made. A simple rule applies: the vapour-barrier film goes on the room side, and the wind-and-moisture membrane on the street side. If they are swapped, moisture from the warm air gets into the insulation and condenses there.

Wet mineral wool loses its insulating properties and does not fully recover them after drying: the fibres become compressed and gaps remain within the layer. Redoing such a shell is expensive, so it is easier to build it correctly from the start.

A ventilation gap of 40-50 mm is left between the insulation and the outer cladding. Through it the moisture that did get into the structure is carried out. A ventilated gap extends the service life of both the insulation and the cladding.

The choice of heat source depends on how often you plan to use the gazebo in winter and whether you need the ability to cook. Each option has its own features.

An electric convector is selected at a rate of 1 kW of power per 10 square metres of insulated space. It is mounted on the wall, takes up no usable area and needs no chimney. There is one downside: if the power goes out, the gazebo is left without heating. A convector with wiring — 45 000 KZT.

Infrared heaters heat people and objects rather than the air, so the warmth is felt right after switching on. In a large room they do not always give even heating. One heater — 45 000 KZT.

A steel pot-belly stove reaches working temperature quickly, while a cast-iron stove-fireplace takes longer to heat up but also gives off heat for longer after the firewood has burned down. A pot-belly stove with a chimney costs from 180 000 KZT, and a cast-iron stove-fireplace with a chimney — from 320 000 KZT. For a winter gazebo with a stove this is a practical option, if there is somewhere to store the firewood.

A brick fireplace is built for a specific gazebo. It is set on a separate reinforced slab at least 200 mm thick, not tied to the gazebo supports, and a basalt gasket is placed between the masonry and the wooden structures. The cost is from 260 000 KZT, with the foundation added on top.

Electric underfloor heating is a supplement, not the main heat source. It is laid at a power of 120-150 W per square metre: it warms your feet but cannot heat the air in hard frost. Underfloor heating with a thermostat — 14 000 KZT per square metre.

A winter gazebo with a fireplace or stove requires strict compliance with fire-safety rules. The chimney from a hearth inside the gazebo: a cross-section of at least 140x140 mm, and an outlet at least 0,5 metres above the roof ridge. If the pipe is lower, the draught worsens and the smoke may come into the room.

The distance from the firebox to unprotected combustible structures is at least 500 mm, and to those protected with a non-combustible finish at least 380 mm. In front of the firebox a non-combustible sheet at least 700x500 mm is laid on the floor with its long side along the firebox. Where the chimney passes through the roof a fire barrier is made — a widening of non-combustible material that prevents the heat from passing to the wooden elements.

A stove takes its combustion air from the room. In an airtight gazebo with no supply of fresh air the stove starts to smoke and the air in the room is quickly used up. That is why supply vents are built in at the bottom of the walls — a grille in the wall or a duct from the under-floor space. Without an air intake, heated gazebos with wood heating are dangerous.

Condensation forms where warm moist air meets a cold surface. On single glazing this happens even at a small temperature difference, and in frost ice inevitably forms along the edges of the glass. A single-chamber double-glazed unit — two panes and one air gap, an installed thickness of about 24 mm — keeps this boundary inside the unit rather than on the surface facing the room.

But even a double-glazed unit does not save a gazebo that is sealed shut. Without air movement moisture builds up in the structures and mould appears on the wood. That is why supply valves or opening sashes are provided, a ventilation gap is left in the roof, and the room is aired after gatherings, when the humidity inside is at its highest.

Using an all-season gazebo in Almaty has its own specifics. The snow load in the foothills reaches 150-200 kg per square metre, so the design roof pitch is set from 25 degrees. At such a pitch the snow slides off on its own, but during a thaw you should watch for ice on the overhangs.

If water is supplied to the gazebo, it is shut off for the winter and the system is blown through, and outdoor taps and hoses are removed so they are not burst by freezing. The chimney is cleaned before the start of the season, and firewood is kept under a canopy: damp firewood gives little heat and a lot of soot.

A floor with underfloor heating is finished with tiles or porcelain stoneware — they conduct heat well and are not afraid of moisture. Furniture is chosen from materials resistant to changes in temperature and humidity: rattan, aluminium, and wood with a protective impregnation. Soft furniture not intended for outdoors is not left in the gazebo in winter.

Under an insulated gazebo a monolithic slab 150 mm thick is more often made: it provides a level, warm floor and a rigid base for the glazing, and costs 75 000 KZT. Under a brick fireplace a separate reinforced slab at least 200 mm thick is poured. A pier foundation and screw piles are also possible, but they are set below the soil freezing depth.

Almaty is in a 9-point seismic zone: the frame corners and joints are reinforced with plates, and the foundation is reinforced with bars from 12 mm. This is a mandatory requirement for all winter gazebo designs in the region.

The price is made up of four parts: the frame and foundation, the shell insulation, the glazing and the heat source. The first three are included in the turnkey price of the structure; the heating is counted separately — from an electric convector at 45 000 KZT to a brick fireplace from 260 000 KZT. Insulating the shell with 100 mm of mineral wool with finishing — 12 000 KZT per square metre, a single-chamber double-glazed unit 24 mm in a PVC profile — 42 000 KZT per square metre, and an insulated entrance door — 65 000 KZT.

The construction time is from 12 to 26 days depending on the size and structure. A warm timber gazebo with double-glazed windows 3x4 m takes 14-18 days to build, and a winter gazebo of glued laminated timber with panoramic glazing 5x5 m — 22-26 days. We carry out the frame, insulation and fitting of the double-glazed units all year round. The only limitation is brick masonry: the mortar needs above-zero conditions while it sets, so in frost the masonry is postponed or a heated enclosure is set up. The warranty on the structure is 5 years, and a measuring visit within Almaty is free. We work across Almaty and the Almaty region: Kaskelen, Talgar, Issyk, Uzynagash.