Private Landlord's Guide to Damp and Mould Prevention

Damp and mould issues can turn a profitable rental property into a liability. Beyond the repair costs, there's potential for disrepair claims, void periods, and reputational damage that affects your ability to let quickly at good rates.

This guide covers what private landlords need to know to prevent problems and respond appropriately when they occur.

Your Legal Obligations

Section 11 of the Landlord and Tenant Act 1985

For most tenancies, landlords must:

• Keep the structure and exterior in repair
• Keep installations for water, gas, electricity, and sanitation in repair
• Keep installations for space heating and water heating in repair

Damp caused by disrepair to any of these falls squarely within your responsibility.

Fitness for Human Habitation

The Homes (Fitness for Human Habitation) Act 2018 requires properties to be fit throughout the tenancy. Severe damp and mould can render a property unfit, giving tenants the right to seek court orders and damages.

HHSRS

Local authorities can inspect private rentals using the Housing Health and Safety Rating System. Category 1 hazards (including serious damp and mould) require mandatory action.

Understanding Damp Types

Condensation Damp

The most common type. Caused by warm, moist air meeting cold surfaces. Characterised by:

• Black mould on walls, ceilings, window reveals
• Water droplets on windows and cold surfaces
• Musty smell
• Worse in winter and in poorly ventilated rooms

Landlord responsibility: Provide adequate ventilation and heating capability. However, if the property is capable of being adequately heated and ventilated, tenant behaviour may be a contributing factor.

Penetrating Damp

Water entering through the building fabric. Signs include:

• Damp patches on walls, often corresponding to external defects
• Worse during or after rainfall
• May cause plaster damage, bubbling paint, staining

Landlord responsibility: Almost always a landlord issue—relates to structural repair obligations.

Rising Damp

Ground moisture rising through walls. Relatively rare compared to condensation. Signs include:

• Tide marks on lower walls (up to about 1 metre)
• Salt deposits on plaster
• Deteriorating skirting boards

Landlord responsibility: A structural issue requiring professional diagnosis and repair.

Prevention Strategies

Property Selection and Purchase

If you're buying to let, consider damp risk:

• Commission a proper survey including damp assessment
• Note construction type (solid walls are higher risk)
• Check existing ventilation provision
• Assess heating system adequacy

Between Tenancies

Use void periods productively:

• Inspect thoroughly: Check for early signs of damp
• Service ventilation: Clean/replace extractor fans
• Check windows: Seals intact, trickle vents open
• Address any issues: Easier without tenant in residence

Ongoing Maintenance

Regular attention prevents small issues becoming expensive problems:

• Annual heating service: Ensure system works efficiently
• Gutter clearance: Blocked gutters cause penetrating damp
• Exterior checks: Pointing, render, roof tiles
• Ventilation verification: Fans working, vents clear

Tenant Communication

At Tenancy Start

Set expectations early:

• Explain how ventilation and heating should be used
• Show them how extractor fans work and when to use them
• Ask them to report any condensation or damp promptly
• Provide written guidance they can refer back to

During Tenancy

Stay in appropriate contact:

• Periodic inspections (with proper notice)
• Seasonal reminders about ventilation in winter
• Prompt response when issues are reported

When Issues Arise

Respond appropriately:

• Don't automatically blame the tenant: Investigate first
• Inspect promptly: Show you take it seriously
• Document everything: Photos, readings, your actions
• Fix what needs fixing: Don't delay necessary repairs

When Tenants Report Damp

Step 1: Acknowledge and Investigate

Within a few days of a report:

• Visit the property (give proper notice)
• Photograph conditions
• Check for obvious causes (leaks, blocked gutters, failed seals)
• Note ventilation and heating provision

Step 2: Diagnose

Determine the likely cause:

• Is there a property defect causing the damp?
• Is ventilation adequate for the property type?
• Is heating sufficient and affordable to run?
• Are there behavioural factors you can identify?

Step 3: Act

Based on your findings:

• Repair any defects promptly
• Improve ventilation if inadequate
• Provide guidance to tenant if behaviour is a factor
• Consider environmental monitoring to track conditions

Avoiding Disputes

Documentation

Good records protect you if disputes arise:

• Inventory photos: Condition at tenancy start
• Maintenance records: What you've done and when
• Communication logs: Advice given to tenant
• Inspection reports: Regular property checks

Proportionate Response

Responding quickly and reasonably to reports makes disputes less likely:

• Don't delay inspections or repairs
• Don't dismiss tenant concerns
• Do fix what's clearly your responsibility
• Do communicate what you're doing and why

When You Disagree

If you believe the issue is behavioural, not property-related:

• Have evidence to support your view (environmental data helps)
• Provide clear, non-judgmental guidance
• Offer practical solutions (better extractor, dehumidifier)
• Consider whether the property has limitations

The Business Case for Prevention

Cost Comparison

Tenant Retention

Good tenants are valuable. Properties with damp issues see:

• Higher turnover (tenants leave)
• Difficulty letting (word spreads)
• Lower achievable rents
• More management time dealing with complaints