How we make money and how the diagnosis works
We are paid in two ways. Both are explained here, and both are labelled on the site wherever they appear.
Quote requests
When you ask for quotes, the company pays €15–35 for the contact. Only with your consent, and to 2 companies at most.
Affiliate links
For condensation we suggest 2–4 products. If you buy one, the shop pays us €1–5. The price for you is the same.
The model
Three hypotheses — condensation (C), rising damp (K) and water ingress (I) — plus a leak alert. Each answer adds points from −3 (against) to +3 (in favour). The points become probabilities through a softmax (τ ≈ 2). High confidence: the leading hypothesis is above 70% and more than 30 points ahead. When two hypotheses are both above 35%, we show a mixed case. Below 50%, we recommend a site visit.
| Sign | C | K | I |
|---|---|---|---|
| Band up to ~1 m from the floor | −2 | +3 | 0 |
| Salts, white powder, crumbling plaster | −2 | +3 | +1 |
| Basement or ground floor, wall against the ground | −1 | +2 | +1 |
| Above the ground floor | 0 | −3 | 0 |
| Black mould in upper corners / behind furniture | +3 | −2 | 0 |
| Black mould spots (elsewhere) | +2 | −1 | 0 |
| Patch in the corners or behind furniture, no mould | +1 | −1 | 0 |
| Droplets on the glass, worse in winter and in the morning | +3 | 0 | −1 |
| Worse after a shower or cooking | +1 | 0 | 0 |
| Habits: laundry indoors, little airing, no extractor fan (max.) | +4 | 0 | 0 |
| Gas or kerosene heater | +2 | 0 | 0 |
| Single glazing, aluminium without a thermal break, home built before 1990 | +1 | 0 | 0 |
| Outside wall (thermal bridge) | +1 | 0 | 0 |
| Patch with a sharp edge (tide mark) | −1 | 0 | +3 |
| Worse 1–3 days after rain | −1 | 0 | +3 |
| Top floor, terrace or roof above, ceiling | +1 | −3 | +2 |
| Same all year round or always growing (+ leak alert) | −2 | +1 | +1 |
| Pipes in the wall, neighbour, meter turning (+ alert) | 0 | 0 | +2 |
| Wall backs onto the neighbour's bathroom or kitchen | 0 | 0 | +1 |
| Wall ≤ dew point + 1 °C (measured) | +4 | −1 | −1 |
| Morning humidity above 70% | +2 | 0 | 0 |
| Morning humidity below 55% | −2 | 0 | 0 |
Weights v0.3, based on building physics. We recalibrate every month against the diagnosis companies confirm on site.
Limits
The diagnosis is indicative and does not replace a site visit. We ask nothing about health. Photos are not used in the calculation — they are for the report and for the company.