Mould
Report.

There is moderate mould growth in both bedrooms, the bathroom and the kitchen of this property. It is condensation mould, not rising or penetrating damp: every wall tested returned normal moisture readings within the fabric, and the growth is confined to cold surfaces and corners where air movement is poor. Three things are driving it. The property has no working mechanical ventilation in either the kitchen or the bathroom, the cavity wall insulation appears to have slumped in the north facing wall leaving a cold band, and there is a high moisture load from indoor drying. A young child sleeps in the rear bedroom, which is the worst affected room, and this raises the assessment to a Category 1 hazard requiring prompt action.

Survey Overview

A mould inspection was carried out at 8 Halstead Rise, Lincoln at the request of the managing agent, following a report of mould from the tenant. The inspection was non-invasive and visual and covered all accessible rooms together with an external inspection of the elevations, roofline and rainwater goods. Relative humidity, air temperature and surface temperature were recorded in each affected room, and wall moisture readings were taken at low, mid and high level to establish whether moisture was present within the fabric of the walls or only on their surfaces. The property was occupied at the time of inspection and the heating was on.

Summary of Findings

The property is a 1970s semi-detached house of cavity wall construction with a solid concrete ground floor and UPVC double glazing throughout. Mould growth is present in four rooms and is moderate in extent, meaning it is clearly visible, covers more than isolated spots, but has not yet colonised whole wall surfaces.

In every affected location, wall moisture readings within the fabric were normal, between 12% and 16% WME. There is no rising damp and no penetrating damp at this property. The growth pattern is the signature of surface condensation: it follows the cold spots. It is heaviest in corners, at window reveals, behind furniture placed against outer walls, and in a distinct horizontal band across the north facing wall of the rear bedroom.

That band is significant. Surface temperature readings across that wall varied by 3.1 degrees between the band and the wall above and below it, which strongly suggests the cavity wall insulation has slumped and left a void. A cold band in an otherwise insulated wall will collect condensation preferentially, and no amount of tenant behaviour change will fully resolve it.

The moisture load in the property is also high. Neither the kitchen nor the bathroom has a working mechanical extract fan; the kitchen fan is present but is not connected, and the bathroom has none. Washing is dried indoors. Relative humidity was 68% in the rear bedroom and 74% in the bathroom at the time of inspection, both well above the threshold at which mould will establish on a cold surface.

No sampling or laboratory analysis was undertaken. The growth is visually consistent with common indoor species associated with condensation, but species cannot be confirmed without testing and none is claimed in this report.

Occupier Comments

The tenant reports that the mould appears each year from around October and recedes in the spring, and that it has become worse over the last two winters. They report wiping the bedroom walls with a supermarket mould spray every few weeks, and that it returns within a fortnight. The kitchen extract fan has never worked in their time at the property. Washing is dried on radiators and on an airer in the rear bedroom because there is no outdoor drying space. The heating is used in the evenings only, for cost reasons. A young child sleeps in the rear bedroom. This is recorded here because it is directly relevant to the risk assessment in this report.

8 Halstead Rise is a three bedroom 1970s semi-detached house of cavity wall construction with a solid concrete ground floor, a pitched concrete tile roof and UPVC double glazed windows throughout. The property is in reasonable general repair, the roof covering and rainwater goods are sound, and no external defects capable of admitting water were identified. The lounge, dining room and small third bedroom presented no mould growth and no elevated humidity, and are not discussed further in this report.

Primary Remedial Works

• Install a humidistat controlled mechanical extract fan to the bathroom, ducted to outside and sized to meet current Building Regulations Part F. This is the single most effective intervention available at this property.
• Connect or replace the kitchen extract fan so that it operates. A fan that has never been wired in provides no benefit and gives a false impression that the kitchen is ventilated.
• Arrange a borescope inspection of the cavity in the north facing wall of the rear bedroom to confirm whether the insulation has slumped. If it has, the cavity should be re-filled by a suitably qualified installer. The 3.1 degree temperature differential recorded across that wall will otherwise continue to produce condensation in the same band every winter.
• Treat the existing mould growth in all four affected rooms using a proprietary fungicidal wash, following the manufacturer's instructions and with appropriate ventilation and personal protection. Supermarket mould sprays remove the staining but do not reliably kill the growth at the root, which is why the tenant is seeing it return within a fortnight.

Recommended / Longer Term

• Consider installing a Positive Input Ventilation unit in the landing ceiling void. In a property of this type with a high moisture load and limited natural ventilation, a PIV unit provides continuous background ventilation that does not depend on windows being opened.
• Redecorate the affected surfaces once the mould has been treated and the ventilation works are complete, using a fungicidal or mould resistant emulsion. Decorating before the ventilation is addressed will simply cover the problem.
• Provide a means of outdoor drying, or a vented or condensing tumble dryer, so that indoor drying is no longer the only option available to the occupier.
• Review the loft insulation depth and the loft hatch seal at the same time as any cavity works, as both affect the surface temperature of the ceilings where growth is present.

Occupier Guidance

• Wipe down the condensation on the bedroom and kitchen windows each morning through the winter. It seems minor, but a window left wet returns that moisture to the room air as the day warms up.
• Open the trickle vents in the front bedroom and leave them open through the heating season. They are fitted and closed, and they cost nothing to use.
• Dry washing outdoors whenever the weather allows. Where it must be dried indoors, use one room with the door closed and the window open rather than the bedroom the child sleeps in.
• Keep furniture at least 50mm clear of the outer walls, particularly the chest of drawers in the rear bedroom, so air can circulate behind it.
• Maintain a low, steady background heat rather than heating only in the evenings. Understandably this has a cost, and it is raised here because a cold wall will attract condensation no matter how well the room is ventilated. The ventilation and insulation works recommended above are intended to reduce how much this matters.

This is a condensation problem, and it is a solvable one. Every wall tested returned normal moisture readings within the fabric, and no external defect capable of admitting water was found. The property does not need damp proofing, chemical injection or replastering, and any contractor recommending those things on the evidence recorded here should be questioned.

What it needs is ventilation and a warmer wall. Three factors are combining: there is no working mechanical extraction anywhere in the property, the cavity insulation in the north facing wall of the rear bedroom appears to have slumped and left a cold band, and the moisture load is high because there is no practical alternative to drying washing indoors. Of the three, the missing extraction is the cheapest to fix and will give the fastest improvement.

It is worth being fair to the occupier here. They have been treating the growth regularly with the products available to them and it keeps returning, which is exactly what will happen while the underlying conditions remain. Occupancy factors are contributing, and the guidance in this report addresses them, but this property would be difficult to keep mould free through a Lincolnshire winter whoever was living in it. The responsibility for the ventilation and insulation defects sits with the building, not the household.

Because a young child sleeps in the worst affected room, this is assessed as a Category 1 hazard and the works should be treated as a priority rather than scheduled at leisure. Once the extraction is installed, the cavity confirmed and made good, and the existing growth properly treated, the property should hold acceptable humidity through the winter and the mould should not re-establish.

Limitations and Use of Report

This report is based on a non-invasive visual inspection on the date stated. No intrusive or destructive investigations were undertaken and concealed areas were not inspected. No laboratory testing, air sampling, or invasive moisture testing was carried out. Findings represent conditions at the time of inspection only and should not be relied upon as a guarantee against future defects. This report provides general guidance on observed damp and mould conditions; it does not constitute a structural or full building survey. Further investigation may be required if conditions change. Moisture readings are indicative and not absolute measurements of material saturation. This report is prepared for the sole use of the client commissioning it and The Damp & Mould Man accepts no responsibility to any third party for its contents. SPECIMEN REPORT. This document is an illustrative example produced by The Damp & Mould Man to show the format and depth of our survey reporting. The property, its address, the client and the findings described are fictional and do not relate to any real property or person. Photographs are taken from our own past remediation work and from our reference library, and are included to illustrate the type of evidence a real report contains.