5.1 — The Purpose of a Site Assessment

A site assessment is the foundation of every professional remediation job. Without a thorough assessment, you cannot correctly identify the type and source of damp, determine the extent of mould contamination, select the appropriate treatment method, or produce an accurate quotation. Skipping or rushing the assessment is the single most common cause of failed remediation.

The site assessment serves multiple purposes: it gathers the information needed to plan the remediation, it creates a documented record of the pre-treatment condition of the property, and it forms the basis of your written report to the client. In the event of a dispute or legal claim, your assessment documentation is your primary evidence.

5.2 — Preparation Before the Visit

A professional assessment begins before you arrive at the property. Good preparation saves time on site and ensures you have the right equipment and information.

Pre-Visit Information Gathering

• Obtain the client's description of the problem — when did it start, where is it, has it been treated before?
• Establish the property type (house, flat, HMO, social housing) and age — this informs likely damp types
• Ask whether any vulnerable occupants are present — this affects your PPE requirements and urgency assessment
• Confirm access arrangements — all affected rooms must be accessible
• Check whether any previous surveys or reports exist — request copies if so

Equipment Checklist

• Pin-type moisture meter with spare batteries
• Non-invasive (capacitance) moisture meter
• Torch — for inspecting dark corners, under-stairs areas, and roof spaces
• Camera or smartphone for photographic documentation
• Tape measure
• Notepad and assessment form, or tablet with digital assessment app
• PPE — minimum FFP2 mask, nitrile gloves, and eye protection for the assessment visit
• Probe thermometer and hygrometer (for measuring air temperature and relative humidity)

5.3 — The Client Interview

The client interview is a critical part of the assessment. Occupants often have information that is not visible during a physical inspection — when the problem started, whether it is seasonal, whether it correlates with weather, and what has already been tried. This information is essential for correct diagnosis.

Key Questions to Ask

• When did you first notice the problem? — Sudden onset suggests a leak; gradual onset suggests condensation or slow penetrating damp
• Has it changed over time? — Growing patches suggest an ongoing moisture source; stable patches may indicate a resolved issue
• Does it correlate with weather? — Worse after rain suggests penetrating damp; worse in winter suggests condensation
• Which rooms are affected? — Pattern of affected rooms helps identify the moisture source
• Has any treatment been carried out before? — Previous failed treatment is important context
• Are any occupants experiencing health symptoms? — Respiratory symptoms, allergies, or skin conditions may indicate significant exposure
• What is the heating and ventilation pattern? — How is the property heated? Are windows opened? Is there mechanical ventilation?
• Are clothes dried indoors? — A major source of moisture generation in condensation cases
• Have there been any recent plumbing works or leaks? — May indicate a plumbing source

5.4 — Visual Inspection

The visual inspection should be systematic and thorough. Work through the property room by room, inspecting all surfaces including walls, ceilings, floors, window reveals, and behind furniture. Do not rely on what the client shows you — inspect the whole property.

What to Look For

• Mould growth — note location, extent, colour, and whether it is active (fluffy, wet) or historic (dry, stained)
• Tide marks — horizontal staining at a consistent height indicating rising damp
• Salt deposits (efflorescence) — white crystalline deposits on masonry surfaces
• Blown or damaged plaster — hollow-sounding plaster at low level indicates salt damage from rising damp
• Staining patterns — water flow paths on walls and ceilings indicate penetrating damp routes
• Condensation indicators — black mould on window reveals, cold corners, and behind furniture
• Building defects — cracked render, missing pointing, defective gutters, failed flashings visible from inside
• Plumbing indicators — staining below bathrooms, adjacent to pipework, or on ceilings below wet rooms

Photographic Documentation

Photograph all findings systematically. Each photograph should be taken from a consistent distance and angle to allow comparison with post-treatment photographs. Include a scale reference where the extent of mould growth is significant. Photograph moisture meter readings on screen where possible.

5.5 — Moisture Meter Assessment

Moisture meter readings must be taken systematically and recorded accurately. A single reading is not sufficient — you need a moisture profile across the affected area to understand the pattern and extent of the damp.

Taking a Moisture Profile

• Take readings at multiple heights on affected walls — typically at floor level, 500mm, 1000mm, and 1500mm above floor level
• Take readings on adjacent unaffected walls to establish a baseline for the property
• Take readings on both faces of the wall where accessible — internal and external
• Take readings in adjacent rooms to identify whether damp is spreading
• Record all readings with their location — a simple sketch plan with reading locations is ideal

Interpreting the Moisture Profile

5.6 — Assessing the Extent of Mould Contamination

Accurately assessing the extent of mould contamination is essential for planning the remediation, selecting the appropriate treatment method, and producing an accurate quotation. The extent of contamination also determines the level of containment and PPE required during treatment.

Contamination Categories

• Minor contamination — isolated patches, total affected area less than 1m², surface mould only. Suitable for standard surface treatment by a competent operative.
• Moderate contamination — multiple patches or a single area of 1–3m², may involve soft furnishings or porous materials. Requires systematic treatment with appropriate containment.
• Severe contamination — extensive growth covering more than 3m², penetrating into building fabric, or involving structural materials. May require specialist contractor involvement, containment, and air filtration.

5.7 — Risk Assessment During the Survey

Before commencing remediation work, you must carry out a risk assessment for the job. Key risk factors to consider include:

• Extent of contamination — determines PPE level and containment requirements
• Presence of vulnerable occupants — may require temporary relocation during treatment
• Access and working at height — ceiling mould or high-level contamination may require steps or scaffolding
• Confined spaces — roof spaces, under-floor voids, and service ducts present additional risks
• Asbestos — properties built before 2000 may contain asbestos in textured coatings, floor tiles, or insulation. Do not disturb suspected asbestos-containing materials without appropriate survey and management
• Electrical hazards — damp environments and electrical installations require careful management

5.8 — The Survey Report

Every site assessment must result in a written survey report — your professional record of the condition found, your diagnosis, and your recommendations.

Survey Report Structure

• Property details — address, property type, age, date of survey, client name
• Summary of client's complaint — what the client reported and when
• Findings — description of all mould growth found, with locations, extent, and photographs
• Moisture meter readings — tabulated readings with locations, ideally with a sketch plan
• Diagnosis — your assessment of the damp type(s) present and their likely cause(s)
• Vulnerable occupants — note if any vulnerable persons are present and implications for urgency or precautions
• Recommendations — proposed remediation treatment, any prerequisite works, and prevention advice
• Limitations — any areas not inspected, any aspects requiring further investigation
• Operative details — name, qualifications, company, date

Key Terms — Module 5

Module 5 Summary

• A thorough site assessment is the foundation of every professional remediation job — never skip or rush it.
• Preparation before the visit includes gathering client information and ensuring you have the right equipment and PPE.
• The client interview often provides the key diagnostic clue — ask open questions and listen carefully.
• The visual inspection should be systematic and cover the whole property, not just the areas the client highlights.
• Moisture meter readings must be taken as a profile across affected areas and recorded with their locations.
• Assess the extent of contamination to determine the appropriate treatment approach, containment level, and PPE requirements.
• Every assessment must result in a written survey report with photographs, readings, diagnosis, and recommendations.

Version 1.0 — August 2026