Thermal insulation in Batumi from the inside: walls, corners and reveals

Where a new build apartment loses heat

Thermal insulation in Batumi apartments almost always starts with the corners. In the new builds we have seen, the load is usually carried by a reinforced concrete frame: columns, beams and slab edges reach the facade, and the gaps between them are filled with blockwork. In winter the concrete sections are colder than the masonry next to them, so they are what mainly needs insulating, with the layer carried onto the masonry at the edges. The weak spots are usually the same:

• the corner of a room where two outside walls and the floor slab meet;
• the strip above the window and below the ceiling, where a beam or slab edge runs;
• the reveals and sill, if the window was fitted on foam alone;
• the floor of an apartment above an archway, a driveway or an open terrace;
• the top-floor ceiling under a flat roof.

Balconies and loggias are insulated to their own scheme, together with warm glazing, and there is a separate page on balcony and loggia insulation.

When insulation won't help

Insulation doesn't cure a leak. If a corner gets wet after wind-driven rain rather than in cold weather, the water is coming through a crack in the facade, the window joint or the slab above. Under lining, a wall like that takes years to dry, so first we close off the water's path and dry the wall.

Insulation doesn't replace air exchange either. Where laundry is dried indoors and people sleep with the windows shut, water appears even on a warm wall, and what helps is air supply and extraction in the bedrooms. Nor do we hide mould under insulation: it carries on growing under a new layer, so antifungal treatment of the walls comes first.

An insulated wall doesn't heat anything by itself. It keeps in the heat from the air conditioner, boiler or convector heater, so heating the apartment in winter is worth sorting out together with the insulation.

Outside or inside

In terms of building physics, a wall is better insulated on the outside: the concrete and blockwork stay warm, the dew point moves into the outer layer, and the room doesn't lose a centimetre. But the facade of an apartment block is shared, and nobody touches it without a decision by the whole building, so in apartments we insulate from the inside.

This method comes at a price. The wall behind the insulation becomes colder than it was, and the humid air of the room must not reach it. We calculate the layer thickness for the material of your wall, and on the room side we fit a vapour barrier with every joint taped, or use an insulation board that lets almost no vapour through by itself. The edge of the floor slab can't be fully covered from the inside: the slab runs right through the wall, and some cold still gets in along it, which we allow for in the calculation.

How we insulate a wall from the inside

The thicknesses in the table are what we get on a typical wall; the exact figure comes from the calculation. We bond the boards over their whole area, not on dabs of adhesive, because condensation collects in the voids behind a board. In the framed system the weak point is the membrane: we tape its joints, its edges at the floor and ceiling and the openings around pipes, and every such detail is photographed before boarding.

At the junction with the ceiling and with an internal wall, cold gets round the insulation. We carry a strip of insulation onto the ceiling and the adjoining wall, otherwise the damp corner simply moves to the edge of the lining. Sockets on an outside wall puncture the vapour barrier, so we move them to internal walls, and where that isn't possible, we fit airtight back boxes.

Window, reveals and sill

A cold reveal says more about how the window was fitted than about the wall. If the window went in on foam alone, without tapes, the foam takes on water over time and crumbles, the joint freezes, and the reveal sweats along its whole height. We redo the joint, insulate the reveal and cover it with a moisture-resistant panel or plasterboard.

If the frame is old, with single glazing or gaps in the casements, insulating around it is pointless: condensation will stay on the glass and run down onto the sill. First we replace the window. How thermally broken aluminium differs from uPVC is explained in the comparison of window profiles.

Floors above a driveway and ceilings under the roof

In an apartment above an archway or an unheated ground floor, the cold comes through the floor. The insulation goes under a new screed: dense extruded polystyrene on the slab, a membrane on top and a reinforced screed at least 5 cm thick. The floor rises by 8–10 cm, so we work out the heights of thresholds and doors before starting.

A ceiling under a flat roof is insulated with mineral wool in a suspended frame, with a vapour barrier underneath. First we check the roof itself: if it leaks above you, the insulation is the first thing to get wet. The roof is shared, its repair is agreed with the building management company, and it has to be finished before we start.

How much thermal insulation in Batumi costs

Internal insulation of an outside wall costs 135–180 ₾ per m² with materials: frame, insulation, vapour barrier with tapes and plasterboard. Labour only, without the insulation and membrane, is 57–72 ₾ per m². Insulated reveals are priced along the window perimeter, at 63–84 ₾ per linear metre.

We measure the insulated surfaces, not the floor: the two outside walls of a 15 m² corner room usually come to 15–20 m² once the window is deducted. Damp walls and moving sockets push the price up, while insulating just one corner and the wall beside the window costs less. The final cost is set after the site measurement and once the estimate is agreed.