If you think that you have rising damp then you need a building surveyor to investigate the problem. They will be able to tell you exactly what is causing the problem and how to fix it.
The Royal Institution of Chartered Surveyors (RICS) lists companies with qualified building surveyors and gives some advice.
If you rent your home then you will probably need to contact your landlord to get the problem fixed. Tell us about the problem if you are in a Dacorum Borough Council-owned property.
Environmental Health will only be able to help if this does not solve the problem, or your landlord refuses to fix the issue.