Frequently Asked Questions

Rising damp is water from the subsoil that climbs up through the capillaries of porous masonry — much like water in a sponge. It occurs when the horizontal damp-proof course at the base of the wall is missing, damaged, or worn out; a typical problem in older buildings constructed before modern standards. In standard brick masonry, it usually rises 50–150 cm, and in stone or mixed masonry, it can exceed 2 m, depending on the porosity of the material and the height of the capillary rise.

It is recognised by three typical signs: a horizontal "line" of damp parallel to the floor, white salt efflorescence on the surface (nitrates, chlorides, and sulphates dissolved in the ground), and seasonal variation — more pronounced in winter when water does not evaporate, and less visible in summer. The salts crystallise as the water evaporates and gradually break down the plaster from within, meaning that merely repainting hides the problem but does not stop it.

Condensation damp forms inside the room, not within the masonry. Warm air holds a certain amount of water vapour; when it hits a surface with a temperature below the dew point (typically a cold corner, a window reveal, or a thermal bridge), the vapour condenses into water. There are three key factors: indoor vapour production (showering, cooking, drying laundry, breath of occupants), insufficient ventilation, and cold surfaces caused by poor thermal insulation or an unheated room.

Characteristic symptoms include: mould in corners and around windows, droplets on glass, wet spots on external walls in winter, and indoor humidity constantly above 65%. In this case, the water does not come from the ground or the façade — it forms directly inside the house, so the solution lies in better ventilation, reducing vapour production, and increasing surface temperatures (insulation, heating).

Hydrostatic damp is water acting on the masonry under hydrostatic pressure — typically in basements and cellars below ground level, where the walls separate the interior from damp soil or reach below the water table. Water in the ground presses on the walls and floor of the basement and penetrates through the smallest cracks, construction joints and even the very structure of the concrete or masonry, if these are not waterproofed against pressurised water.

Symptoms: localised wet patches at any height (unlike the horizontal line of rising damp), drips or rivulets of water running down the walls, water in corners after heavy rain or in spring during the thaw. The term structural damp is used more broadly for all damp that enters the structure through a building failure — missing drainage, damaged external waterproofing, an unventilated basement. The solution is fundamentally different from rising damp: it requires intervention from the outside (drainage, waterproofing the walls against pressurised water, repairing rainwater downpipes). Injection at the base of the wall on its own will not stop hydrostatic water — it only addresses capillary rise.

They differ in the source of the water and the direction from which it enters the masonry. Rising damp climbs up from below through the capillaries of the masonry, out of the ground. Hydrostatic damp comes in from the side or from below under hydrostatic pressure (typically basements below the water table). Penetrating damp passes through the external wall — rain through a damaged façade, a cracked downpipe, a leaking roof. Condensation damp forms inside the room when damp air condenses on a cold surface.

Each calls for a different solution: rising — a horizontal barrier at the base of the wall (injection, sawing); hydrostatic — external waterproofing and drainage; penetrating — repairing the façade, downpipes or roof; condensation — ventilation, insulation, reducing vapour production. The worst mistake is to confuse the cause and treat the wrong type — the symptom disappears for a few months and the water comes back.

Three quick signals: the line of the damp (horizontal = rising, localised = penetrating), white efflorescence (a strong sign of rising damp), mould in corners around windows (a strong sign of condensation). When in doubt, take our short quiz or have the damp measured on site.

Salt from beneath the foundations rises with the water and crystallises on the surface as the water evaporates. Efflorescence is a diagnostic signal — if you can see it, the water really is moving through that wall. The salt also damages the plaster from within; merely repainting hides the problem but does not solve it.

Mould starts to grow when the plaster damp is above 70%, within 24–72 hours. The spores released into the air are allergens. In people with asthma or in small children, symptoms can appear within a few weeks. A damp wall is never just a cosmetic problem.

Dry brick has 5–10 times better thermal insulation than damp brick of the same thickness. The water in the pores conducts heat outwards. Buildings with an extensively damp basement typically use 20–30% more heating than the same buildings when dry.

Surface symptoms (efflorescence, mould) can be handled with cleaning and an anti-mould coating. The cause — water in the capillaries of the masonry — is not addressed by any coating or plaster. If you do not stop the source of the water, the damp returns within a few months. A permanent solution requires technology (WetBRICK® gel injection, for example, works for the long term).

It helps with condensation (humidity in the air). With rising damp it does not help at all — the water does not come from the air, it comes from the ground. Ventilation can only make the cold feel worse, because dry masonry would insulate better.

Yes, the first consultation, including measurement of the masonry damp, is free and without obligation. We measure using capacitive and microwave methods — no drilling, no damage to the plaster.

A capacitive moisture meter for surface measurement, a microwave moisture meter for depths of 5–30 cm, a thermal camera to map cold spots, and where necessary the carbide method (CM) for precise determination of the moisture content by mass, when documentation for the heritage authorities is needed.

For a standard family house, 60–90 minutes. For an apartment building, 2–4 hours. For a heritage building, depending on the scope, typically half a day. We tell you what we found right after the survey — no waiting weeks for an "assessment".

A row of holes 18 mm in diameter is drilled into the wall in a single horizontal line at the base of the wall, or in a cross grid across the whole area. A special material is injected into the holes (in our case WetBRICK® gel), which spreads through the capillaries and forms a barrier. Water from the subsoil no longer rises through the masonry.

Silicone is liquid and acts as a water-repellent coating in the pores. The gel is a polymer that cross-links directly in the masonry and forms a mechanically solid barrier. The gel works better in very wet walls (>80% damp) and in irregular masonry (mixed, stone).

The wall is cut horizontally with a diamond wire or saw. A damp-proof membrane (e.g. PE) is inserted into the cut. Effective, but aggressive — it cuts across the structural line of the wall and is almost never permitted for heritage buildings.

The principle: an electric charge in wires set into the wall is meant to reverse the capillary flow. In practice the results vary; independent studies do not confirm lasting effectiveness. We do not recommend it as a primary solution.

Yes — you will find a complete comparison with the five main methods in the Comparison of methods section. The short version: WetBRICK® wins in the categories "very damp masonry", "heritage buildings" and "durability"; chemical injection is cheaper for standard brick walls in good condition.

Three main products: WetBRICK® gel injection (a permanent solution to damp), Epasit® renovating plasters (surface regeneration after injection), Rotia® disinfection of spaces (eliminating mould, bacteria and viruses). Our specialisms: family houses, apartment buildings, heritage buildings, industrial properties and healthcare facilities.

We operate throughout Czechia and Slovakia. For projects in the rest of the EU (typically heritage buildings), we have a separate team that arranges each project on a case-by-case basis.

Yes. No job is too small for us. A minimum project typically starts at 15 m² of masonry.

Both. For homeowners' associations and cooperatives, we provide standardised documentation for the approval process (technical report, cost estimate, schedule).

Yes. For projects in heritage buildings, we routinely prepare a technological procedure, a technical report, and material safety data sheets, which we submit for assessment by the heritage authorities. Work proceeds only after their consent has been granted.

10 years for the combination of WetBRICK® + Epasit®, and 5 years for injection alone without renovating plaster. The warranty covers the functionality of the barrier — if rising damp reappears in the treated area within the warranty period, we will repair it free of charge.

The price always depends on the type and condition of the masonry, the area, accessibility, and related work. We deliberately do not provide quotes without an on-site survey to avoid sharing misleading figures. After a free consultation, we will send you a detailed estimate itemising all costs.

For larger jobs, yes, on an individual basis. For standard family houses, we usually require a 50% deposit and 50% upon completion.

For heritage buildings, yes — the Ministry of Culture, the National Heritage Institute, and regional programmes. For ordinary residential buildings, partly through the New Green Savings programme (insulation component). We can help you navigate current programmes, but we are not a grant agency.

No. We work while the building remains in normal use. Vibration is minimal, drilling noise is comparable to ordinary DIY, and we extract the dust. In apartment buildings, we manage access floor by floor according to the schedule.

Typically 1–3 days per 100 m² of masonry for standard brick. For stone masonry or difficult access, it can extend to 5–7 days. Epasit® renovating plaster is applied once the wall has dried out, typically 4–6 weeks after injection.

Water in the capillaries needs time to dry out. The first visible improvements (patches fading, the dry area growing) appear within 2–6 months. Full drying of the masonry takes 6–18 months, depending on wall thickness and the room's climate.

After injection, water remains in the wall and must escape. Ordinary plaster would trap it, crack, and allow salts to effloresce again. Epasit® is a renovating plaster with high porosity — it lets the water out and traps the salts inside, where they do no harm. Together with WetBRICK® injection, it provides a full 10-year warranty.

Space disinfection — it eliminates mould, bacteria, and viruses on surfaces and in the air. We recommend it after injection in spaces where there was extensive mould. It is done quickly (a single treatment, a few hours), using chemicals that are not hazardous to people or animals once the space has been aired out.

Yes, it is our speciality. WetBRICK® is widely used in heritage conservation because it requires no demolition, no cutting, and no other intervention in the structure. Our reference projects include Bratislava Castle and the Zwinger in Dresden.

We prepare complete documentation: a description of the technology, WetBRICK® material data sheets (they are neutral and do not affect the aesthetics), safety data sheets, and a proposed drilling layout. This is submitted to the National Heritage Institute or the local heritage authority. Approval typically takes 4–12 weeks. We carry out the work only after consent has been given.

The 18 mm drilled holes, whether in a single line at the base of the wall or in a cross grid across the whole area, are filled after injection to match the texture of the surrounding plaster. After 6 months, they are indistinguishable at a normal viewing distance. For exposed masonry (face brick, stone), we adjust the procedure slightly so the holes are placed in less visible joints.