Mould is one of the most common complaints from flat owners in Batumi: black spots in the corner behind a wardrobe, a grey bloom on the window reveals (the side surfaces around the window frame), a musty smell in the bathroom. Owners often discover it when they come back after several months away and the flat has been shut the whole time. Below we look at where mould comes from, how to prevent it during a renovation and what to do if it has already appeared.
Why mould is so common in Batumi
Batumi is a humid subtropical city by the sea. Humidity is high almost all year round, it rains a lot, and in winter the temperature difference between outside and inside is enough for condensation to form on cold surfaces. Mould needs three things: moisture, organic material (wallpaper, plasterboard, dust, adhesive) and still air. In a closed flat with poor ventilation, all three conditions are met on their own.
The main sources of the problem are usually these:
- Condensation. Warm, humid air touches a cold wall, window or reveal and leaves water on it. If this happens every day, spots appear within a couple of months.
- Weak ventilation. The PVC windows seal tightly, the bathroom extractor fan does not work or is clogged, and the air in the flat is hardly ever replaced.
- Thermal bridges. Corners of external walls, junctions with the floor slabs, poorly insulated reveals — these areas are always colder than the rest of the wall, and that is exactly where moisture settles.
- Leaks. A badly sealed shower, a crack in the grout, a dripping waste trap, water from the neighbours upstairs. The moisture soaks into the wall and stays out of sight for a long time.
- Air conditioner. A dirty indoor unit and a badly routed drain are a separate story, covered below.
Ventilation: start with the air
Without proper air exchange, even expensive materials will lose the battle. Check whether there is a draught in the ventilation ducts in the kitchen and bathroom: hold a sheet of paper or a lighter flame up to the grille. If there is no draught, the duct may be clogged or was blocked off during renovation work. In a bathroom without a window, it is worth fitting a mechanical extractor fan with a non-return valve — ideally with a timer or a humidity sensor, so it keeps running for a while after a shower.
Windows with a micro-ventilation setting or trickle vents give a small, constant supply of fresh air without chilling the flat. This matters most for owners who spend long periods abroad: a flat sealed shut for six months will almost certainly greet you with a damp smell. If the flat stands empty, it makes sense to arrange for someone to air it at least from time to time and, if possible, to leave a dehumidifier or an air conditioner in dry mode running.
Bathroom: the waterproofing you cannot see
In a bathroom, the main protection is hidden under the tiles. Before tiling, the floor and walls in the shower area are coated with waterproofing that runs up onto the walls, and reinforcing tape is laid in the corners and at the joints. Pipe penetrations and the floor drain need special attention. If this layer is done badly, water seeps into the screed and walls for years, and you only notice when stains show through at the neighbours’ or in the hallway.
That is why we photograph all hidden work — waterproofing, pipes, wiring — before it is covered with tiles or plasterboard. You receive these photos in your weekly report, together with videos. Even several years later, they show where a pipe runs and how the waterproofing was done. We give a 5-year warranty on hidden engineering work.
Besides waterproofing, a bathroom needs good grout made for wet areas, sanitary sealant along the joints of the bath and shower tray, and a floor that slopes towards the drain so water does not pool.
Windows, reveals and thermal bridges
A classic place for mould is the window reveals and sill. The usual cause is that the window’s installation joint is not protected from moisture, or the reveal is not insulated and stays cold. During a renovation, it is worth checking the installation joint, redoing it if necessary and insulating the reveals, rather than simply filling and painting them. If the radiator or air conditioner does not warm the area by the window and a wide sill blocks the flow of warm air, condensation will keep coming back.
External corners and walls that face the street also need checking. Sometimes the fix is internal insulation of the problem section; sometimes it is enough not to push a wardrobe flat against such a wall and to leave a gap for air.
Air conditioner: a source of moisture and dirt
In Batumi, the air conditioner runs for many months of the year, and water constantly forms inside it. If the drain hose has the wrong slope, is kinked or is clogged, water can drip onto the wall and furniture. Inside a dirty unit, deposits build up on the heat exchanger and in the drain tray and are then blown around the room with the air.
Have the air conditioner cleaned at least once a year, and more often if you use it heavily. We offer air conditioner cleaning from 70 ₾ and check the drain as well if needed. If the unit is being installed during a renovation, it is better to hide the pipe run and drain in the wall in advance — and photograph them before they are closed up too.
Materials for a humid climate
Without naming specific brands, the general principles are:
- In wet areas — moisture-resistant plasterboard, cement boards and cement-based plasters instead of standard gypsum products.
- Before the finishing coat — primers with antiseptic (anti-mould) additives, especially on problem walls.
- Paints for damp rooms that can be washed. They absorb less moisture and are easier to clean.
- Be careful with non-woven and paper wallpaper on external walls and in bathrooms: mould can grow underneath it unnoticed.
- For bathroom joints — epoxy grout or a special grout for wet areas, plus sanitary silicone.
During a renovation and in a lived-in flat: what to do
If the renovation is still ahead, this is the best moment to solve the problem as a whole: check the ventilation, do the waterproofing, insulate the reveals, route the air conditioner drains correctly and choose the right materials. Make sure the screed and plaster have dried out before finishing — if you cover a damp base with paint or laminate, the problem will come back from inside.
If mould has already appeared in a flat you live in, find the cause first: condensation, a leak or ventilation. Simply painting over the stain is pointless — it will show through again within a season. The affected area has to be cleaned back to the base (sometimes the plaster has to come off), treated with an antiseptic, dried, and only then refinished. Mould is harmful to health, so serious cases are best left to specialists in mould, damp and waterproofing rather than scrubbed off yourself without protection.
If you are not sure where the moisture is coming from, a call-out from one of our tradesmen costs 50 ₾: they will inspect the flat and tell you what to do. If you need a renovation, the estimate will be ready 2 days after measuring.
Want to deal with the damp in your flat, or renovate with mould protection built in from the start? Get in touch — we will take a look, price the work and send you a clear plan, even if you are abroad right now.