Rising Damp: Signs, Causes and How to Fix It

If you've noticed peeling paint, crumbling plaster or a dark line appearing near the bottom of your walls, you may be dealing with rising damp.

Rising damp is one of the most common problems we see in older properties across Kent, particularly Victorian and Edwardian homes. Left untreated, it can damage plaster, timber, decorations and even affect the value of your property.

At Thanet Plastering, we help homeowners identify the real cause of damp problems and provide long-lasting solutions that protect their homes for years to come.

What Is Rising Damp?

Rising damp occurs when moisture from the ground travels upwards through brickwork and plaster by a process called capillary action.

Most modern buildings include a damp proof course (DPC) designed to stop this movement. However, in older properties the original damp proof course may have failed, deteriorated or be completely absent.

As moisture rises through the walls, it carries salts from the ground which can cause significant damage to internal finishes.

Common Signs of Rising Damp

The most obvious signs include:

Tide Marks

A distinctive brown or yellow line can often be seen running horizontally along internal walls, typically between 300mm and 1 metre above floor level.

Crumbling Plaster

Moisture and salts break down the plaster from within, causing it to become soft, flaky and unstable.

White Salt Deposits

Known as efflorescence, these white powdery deposits appear as moisture evaporates from the wall surface.

Rotting Skirting Boards

Timber in contact with damp walls can become soft, swollen or begin to rot over time.

Peeling Paint and Wallpaper

Decorative finishes struggle to adhere to damp surfaces, leading to bubbling, flaking and peeling.

Rising Damp vs Condensation

Many homeowners mistake condensation for rising damp.

The two problems have very different causes.

Rising Damp	Condensation
Starts at ground level	Often appears around windows
Creates tide marks	Produces black mould
Causes salt deposits	Causes water droplets
Damages skirting boards	Common in bedrooms and bathrooms
Usually affects older properties	Linked to poor ventilation

Understanding the difference is essential before carrying out any repairs.

Why Are Victorian Houses More Susceptible?

Kent has many beautiful Victorian properties, particularly in Margate, Ramsgate, Broadstairs and Canterbury.

These homes often experience rising damp because:

• Original damp proof courses have failed.

• External ground levels have been raised over time.

• Traditional materials require breathable solutions.

• Previous repairs may have trapped moisture inside walls.

Treating older buildings correctly requires experience and an understanding of traditional construction methods.

What Causes Rising Damp?

Common causes include:

Failed Damp Proof Courses

Over time, existing damp proof barriers can break down and lose effectiveness.

Bridged Damp Proof Courses

External paving, flower beds or render can sit above the damp proof course, allowing moisture to bypass the protection.

Poor Drainage

Standing water around foundations can increase moisture levels within masonry.

Inappropriate Repairs

Modern impermeable materials can trap moisture within older walls rather than allowing them to breathe naturally.

How Is Rising Damp Treated?

The correct treatment depends on the condition of the property and the underlying cause.

Typical solutions include:

Damp Proof Course Installation

New damp proof systems can prevent moisture rising through masonry.

Removing Contaminated Plaster

Damaged plaster affected by salts often needs to be removed and replaced.

Replastering With Appropriate Materials

Breathable systems help walls dry naturally and reduce future problems.

Addressing External Ground Levels

Sometimes lowering external pathways or removing bridges over the damp proof course is necessary.

Can Rising Damp Be Fixed Permanently? Yes.

When the root cause is correctly identified and appropriate repairs are carried out, rising damp can be resolved permanently.

The key is avoiding quick fixes that simply cover up the symptoms.

Painting over damp walls or using anti-mould products without treating the underlying issue rarely works and often leads to more expensive repairs later.

Free Rising Damp Surveys Across Kent

Tel: 07852 701996

At Thanet Plastering, we provide honest advice and practical solutions for homeowners experiencing damp problems throughout Margate, Ramsgate, Broadstairs, Canterbury and the surrounding areas.

If you've noticed tide marks, crumbling plaster or persistent damp patches near floor level, we can assess the problem and recommend the most effective treatment.

Contact us today to arrange a free rising damp survey and protect your property before minor issues become major repairs.