Damp Type Diagnostic Tool
Seven questions about what you can actually see — pattern, height, weather, mould — and a structured first opinion on which damp you're dealing with, with the right next step.
What kind of damp do I have? The four mechanisms leave different evidence: rising damp draws a low tide mark with salts; penetrating damp tracks rainfall at any height; condensation grows black mould on cold spots; below-ground ingress wets basements and cellars. This tool scores your answers against those signatures and returns the most likely type with a confidence view and the matching guide, service and survey recommendation. It's a structured first opinion — the same pattern-reading a surveyor starts with — not a diagnosis; anything recurring, structural or pre-purchase deserves the £280–£450 survey that confirms mechanism definitively.
Use the diagnostic
Answer the questions
Answer each question from what you can observe. Skip none — 'not sure' is always an option.
1. Where is the damp?
2. Is there a horizontal 'tide mark' with white salty deposits?
3. Does it get worse during or just after rain?
4. Is there visible black mould?
5. Do windows stream with condensation on winter mornings?
6. Any of these outside? (pick the strongest match)
7. How does the affected area smell?
Related services and guides
Damp Surveys
The service this tool points toward — diagnosis-first, independent qualified providers.
View the serviceDamp Proofing (all services)
The service this tool points toward — diagnosis-first, independent qualified providers.
View the serviceDamp vs Condensation: How to Tell the Difference
The in-depth guide behind this tool's logic.
Read the guideRising Damp vs Penetrating Damp: Diagnosis Guide
The in-depth guide behind this tool's logic.
Read the guideDamp Type Diagnostic Tool FAQs
It applies the same pattern-signatures a surveyor starts from, so a clear result is a strong first opinion. Mixed or low-confidence results usually mean mixed mechanisms — common in period stock — which is precisely when the £280–£450 survey with depth profiling earns its fee.
The tool tells you so and recommends a survey: near-ties usually mean two mechanisms coexisting (a bridged DPC plus condensation, say), and each needs its own remedy.
No — scoring runs entirely in your browser. Nothing is transmitted and no contact details are requested.
As a viewing-day framework, absolutely. For the purchase itself, pair it with the Homebuyer Damp Checklist and a pre-purchase specialist survey — the findings become negotiating material.
Want a professional answer, not just an estimate?
Call today or book a survey — the right independent qualified specialist, matched to your property.