Understanding Damp: Types, Causes and Treatment Costs

Damp is one of the most common defects found during property surveys in Milton Keynes. Understanding the different types of damp, their causes, and treatment options is essential for any property buyer. This guide explains everything you need to know about moisture problems in residential properties.

The Three Main Types of Damp

1. Rising Damp

Rising damp occurs when groundwater rises up through walls via capillary action. This happens when the damp proof course (DPC) fails or is absent.

Signs of rising damp:

• Tide marks on walls (typically up to 1 meter high)
• Damp, discolored patches on plaster
• Peeling wallpaper or paint
• White salt deposits (efflorescence)
• Rotting skirting boards
• Musty smell in affected rooms

Common causes:

• Damaged or absent damp proof course
• Ground levels raised above DPC
• Bridging of DPC by render or debris
• Porous bricks in older properties

Treatment costs: £1,500 - £4,000 depending on affected area. Involves installing chemical DPC or replacing physical barrier.

2. Penetrating Damp

Penetrating damp occurs when water enters through walls, roofs, or windows due to defects in the building fabric.

Signs of penetrating damp:

• Damp patches appearing after rainfall
• Staining that worsens in wet weather
• Patches at any height (not just low down)
• Mold growth on walls
• Wet patches around windows or chimneys

Common causes:

• Damaged roof tiles or flashing
• Blocked or leaking gutters
• Cracked render or pointing
• Failed window seals
• Porous brickwork
• Defective chimney stacks

Treatment costs: £500 - £3,000 depending on source. Often involves repointing, roof repairs, or gutter replacement.

3. Condensation

Condensation is the most common form of damp, caused by excess moisture in the air meeting cold surfaces.

Signs of condensation:

• Water droplets on windows and walls
• Black mold on walls and ceilings
• Worse in bathrooms and kitchens
• Musty smell
• Appears in winter months
• Affects cold corners and window reveals

Common causes:

• Poor ventilation
• Inadequate heating
• Lack of extractor fans
• Drying clothes indoors
• Modern sealed windows without trickle vents

Treatment costs: £200 - £1,500. Installing ventilation, insulation, or dehumidifiers usually resolves the issue.

How Damp Affects Property Purchase

When a building survey identifies damp, it impacts your purchase in several ways:

• Price negotiation - Use treatment costs to reduce purchase price
• Mortgage implications - Severe damp may affect lending
• Insurance - Some insurers require treatment completion
• Future costs - Budget for repairs and ongoing maintenance
• Health concerns - Mold can cause respiratory issues

Damp Treatment Options

For rising damp:

• Chemical DPC injection (most common)
• Physical DPC insertion
• Replastering affected walls
• Typically guaranteed for 20-30 years

For penetrating damp:

• Repair source (roof, gutters, pointing)
• Waterproof rendering
• Cavity wall insulation checks
• Window seal replacement

For condensation:

• Install extractor fans
• Improve ventilation (trickle vents)
• Add insulation
• Upgrade heating system
• Use dehumidifiers

Frequently Asked Questions

Should I walk away from a property with damp?

Not necessarily. Condensation is easily treatable. Rising and penetrating damp can be fixed, but get quotes first. Only walk away if treatment costs are excessive or the property has multiple serious issues.

How much does a damp survey cost?

A specialist damp survey costs £150-£300. However, a RICS Level 2 or Level 3 survey includes damp assessment as standard and provides broader property insights.

Can I get a mortgage on a property with damp?

Minor damp issues won't prevent a mortgage. Severe rising damp may require treatment before lending is approved. Your surveyor will advise if damp affects mortgageability.

How long does damp treatment take?

Rising damp treatment: 1-3 days plus 2-4 weeks drying time. Penetrating damp: Depends on repairs needed (1-7 days typically). Condensation: Immediate improvements with ongoing ventilation management.

Is damp covered by insurance?

Generally no. Building insurance covers sudden damage (burst pipes) but not gradual deterioration like damp. However, damage caused by damp (like rot) may be covered.

Conclusion

Understanding damp is crucial for property buyers in Milton Keynes. While damp is common, it's treatable when identified early. A professional property survey will diagnose damp types accurately and provide treatment cost estimates, helping you negotiate or plan repairs.

Don't let damp fears prevent you from buying the right property - just ensure you understand the extent, causes, and costs before proceeding.