Balcony insulation in Batumi without condensation or mould

When to insulate a balcony and when not to

Balcony insulation in Batumi makes sense if you want to use the balcony as a room in winter: for a desk, a children's corner or a wardrobe. That takes warm glazing with double-glazed units, an insulated floor, walls and ceiling, and a source of heat. If any of these is missing, the insulation starts working against you.

The most common mistake looks like this: the walls are insulated under a cold aluminium frame with single glass. Warm, moist air from the apartment reaches the glass and frame and settles on them as water, the water runs down onto the sill and into the insulation, and by spring there is mould behind the lining. If you don't plan to change the frame, the balcony is better left cold. If you do, we fit the warm frame first. The types of frames with double glazing are covered on the page about balcony glazing.

If the balcony is being joined to a room, the wall between them is checked first. What can be done with it is covered in the section on room design.

Dew point: where the water on a balcony comes from

In winter the air in a Batumi apartment is humid. At +20 °C and 65% humidity the dew point is about +13 °C, and any surface colder than that gets covered in water. The concrete parapet, the floor slab and the ceiling slab of a balcony are colder than that in winter, so without insulation condensation settles on them even behind good double glazing.

Insulation moves the dew point inside the construction: it ends up within the insulation itself or on the concrete behind it. If vapour from the room gets there, it turns into water where nobody can see it. That is why we fit a vapour barrier on the room side and tape its joints and its junctions with the frame, slabs and walls. We calculate the insulation thickness so that the inner lining stays warmer than the dew point.

Floor, walls and ceiling: what we use

For the floor and parapet we use extruded polystyrene: it absorbs almost no water and doesn't compress under the screed. Mineral wool goes into the frame on the walls and ceiling, where the vapour barrier covers it reliably. We don't use white expanded polystyrene on balconies, as it is brittle and takes on more moisture than the extruded kind.

The balcony slab continues under the wall into the room, and cold travels along it into the apartment: in winter there can be a cold strip on the floor by the balcony door. We take the insulation right up to the threshold and the walls, and fill the joints between boards with foam. The waterproofing under the insulation is done the same way as in an ordinary balcony renovation, carried up the walls and under the threshold.

Underfloor heating, heat and ventilation

An insulated balcony needs its own heat source: the air conditioner in the room if the balcony opens into it, an electric convector heater or underfloor heating. The floor by the glazing is the coldest spot, and warming it gets rid of condensation in the bottom corners, so underfloor heating works better here than a convector.

We lay the electric mat in the tile adhesive bed or under a thin screed and connect it on a separate circuit through an RCD, with a thermostat and a floor sensor. Its cable runs in the wall and is photographed before it is covered. We don't lay the mat under wardrobes and cabinets, because it overheats under furniture.

Without fresh air, even a warm balcony mists up by morning. We leave a panel with a micro-ventilation setting or fit a trickle vent, and if laundry is dried on the balcony, it also needs an extractor fan or a dehumidifier.

How much balcony insulation in Batumi costs

Insulation costs from 130 to 180 ₾ per m² of surface. The price covers labour and materials: insulation, vapour barrier, tapes, frame and lining. We count the area across all the surfaces being insulated, that is the floor, walls, parapet and ceiling together, so for a balcony with five square metres of floor it comes to several times that.

Priced separately are skim coating the walls for painting, from 23 to 36 ₾ per m², laying electric underfloor heating on up to 5 m² for 210–240 ₾ (not including the mat and thermostat), and electrical points at 42–66 ₾ for each socket, switch or light. Warm glazing isn't included in this price: thermally broken aluminium costs 895–1,080 ₾ per m² of opening, and uPVC with double glazing is cheaper.

It costs more when the walls are damp and have to be treated and dried first, when the ceiling is uneven, or when someone else's insulation has to be redone. It costs less if a warm frame is already in and the joint around it has been done properly. The final cost is set after the site measurement and once the estimate is agreed.

How we check the layers before the lining goes on

Insulation is concealed work: once the lining is on, neither the insulation nor the vapour barrier can be seen. We photograph each layer before it is closed up: the joints between boards, the taped membrane, the junctions with the frame and threshold, and the underfloor heating cable route. The photos come in the weekly report and go into the handover file.

During the first winter it is worth keeping an eye on the corners at floor and ceiling level. Dark patches or damp reveals after insulation point to a gap in the vapour barrier or a cold bridge, and with the photos of the layers such a spot can be found without opening up the whole balcony. If our work is the cause, it is a warranty case.