Damp Proofing & Rising Damp Treatment

We find the real cause of the damp in your walls, then fix it properly, with guaranteed treatments and a finish you can decorate.

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PCA-qualified surveyors
Commission-free advice
Fixed, written quotations
Insurance Backed Guarantees
Trading since 1971

Experts in Damp Proofing in London and the Home Counties Since 1971

Damp can affect any property, damaging plaster, decorations, floors and timber if it is left alone. But damp walls don’t always mean rising damp, and treating the wrong problem wastes time and money.

At Tapco HomeDry our Property Care Association (PCA) qualified surveyors identify exactly what is causing the damp before recommending anything.

The three main types of damp

Rising damp

Ground moisture travels up through brick and mortar where the original damp proof course has failed, deteriorated or been bridged by raised ground levels, rendering or debris in a cavity. It typically leaves a tide mark up to about a metre high and salt deposits in the plaster.

Penetrating damp

Rainwater gets in through defects: failed pointing, cracked render, leaking gutters and downpipes, defective flashings or roofs. It can appear at any height, often gets worse after heavy rain and is common on exposed walls.

Condensation

Warm, moist air from cooking, washing and breathing condenses on cold surfaces. It causes black mould on walls, ceilings and window reveals and is frequently mistaken for rising damp. Read about condensation control.

Signs your property may need damp proofing

Damp problems usually start gradually and become more expensive the longer they are left. Look out for:

Damp patches on internal walls, especially near the floor
Tide marks above skirting boards
White, fluffy salt deposits (efflorescence)
Peeling wallpaper and bubbling or flaking paint
Crumbling or hollow-sounding plaster
Rotting skirting boards, door frames or floor timbers
Black mould and a musty smell
Walls that feel cold and damp to the touch

Before: damp-damaged plaster removed to raw brickwork. After: a new damp proof course and a breathable, salt-resistant plaster finish.

Why diagnosis comes first

Many damp problems are treated incorrectly because the visible symptoms look alike. A chemical damp proof course will not stop rain coming through cracked render, and no amount of injection will fix condensation. That is why every job starts with a proper survey.

Our surveyors use calibrated damp meters, hygrometers and surface thermometers, check the external walls, ground levels, gutters and drainage, and look at how the room is used and ventilated. Where rising damp is suspected, salt analysis helps confirm it. You then receive a written report that explains what is happening and why, and what we recommend.

Honest advice, no commission. Our surveyors are not paid commission. If the cause is a leaking gutter or condensation rather than rising damp, we will tell you, and we won’t sell you a treatment you don’t need.

How we treat rising damp

Remove contaminated plaster

Plaster affected by damp and salts is carefully removed, usually to a height of around a metre, with dust controlled and floors and furniture protected.
Install a new damp proof course

A water-repellent DPC cream is injected into a continuous mortar course at the base of the wall. It spreads through the mortar and cures to form a barrier against rising moisture.
Replaster with a salt-resistant system

The wall is replastered with a breathable, salt-resistant system designed for damp-proofed walls, ready for decoration once dry.
Guarantee and aftercare

You receive a written guarantee, which can be protected by an Insurance Backed Guarantee, and advice on decorating and keeping ground levels and gutters clear.

How we treat penetrating damp

Penetrating damp is fixed at its source. Depending on what the survey finds, that can include repointing, render repairs, replacing gutters and downpipes, re-forming flashings, lowering ground levels against the wall, or treating porous masonry with a breathable water repellent. Because we have our own property maintenance team, we can carry out the external repairs and the internal making good as one job.

Period and listed properties

Older buildings built with lime mortar, soft brick, flint or stone were designed to let moisture evaporate. Covering them in cement render, gypsum plaster or plastic paints can trap damp and make things worse. For period and listed properties we recommend breathable, lime-compatible repairs and only use injection where it is genuinely appropriate.

What affects the cost of damp proofing?

Every property is different, so we always quote after a survey. The main factors are:

The cause of the damp and whether external repairs are needed
The length and thickness of the walls being treated
How much plaster needs to be replaced, and the finish required
Access, and whether kitchens, radiators or fitted furniture need moving
Whether timber such as skirting boards or joists has decayed

You will receive a fixed, written quotation with no hidden extras.

Why choose Tapco HomeDry?

Damp and timber specialists since 1971, visiting around 4,000 properties a year
PCA-qualified, commission-free surveyors
Members of TrustMark and the Basement Waterproofing Association, and CHAS accredited
Written guarantees, with Insurance Backed Guarantees available
Our own trained teams carry out the work, from survey to replastering

1971

Established in Thames Ditton

55+

Years of damp & timber expertise

4,000+

Properties visited every year

Counties covered across the South East

Why choose Tapco

Damp Proofing done properly. Diagnosed first, guaranteed after.

Every property gets an individual assessment from a qualified surveyor before anything is recommended.

A little more about us

01

Commission-free surveys

Our PCA-qualified surveyors are not paid commission, so we only recommend the work your building genuinely needs.
02

Fixed, written quotations

After your survey you get a clear written report and a fixed quote, with no hidden extras.
03

Our own trained teams

Our own teams carry out the work, protect your home, keep dust down and leave everything clean.
04

Guaranteed for peace of mind

Written guarantees, which can be protected by an Insurance Backed Guarantee.

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Get started today

If you’ve noticed any of these issues, arranging a professional survey is the best way to identify the cause and prevent further damage.

Request a survey Or give us a call020 8398 6663

Frequently asked questions

How do I know if I have rising damp?

Typical signs are a tide mark up to about a metre above the floor, white salt deposits, peeling paint or wallpaper, crumbling plaster and rotting skirting boards. The same signs can be caused by penetrating damp, condensation or a leak, so a survey with calibrated meters is the only reliable way to know.

What is a damp proof course?

A damp proof course (DPC) is a barrier near the base of a wall that stops moisture rising up from the ground. Older properties used slate or bitumen, which can deteriorate or be bridged. Where a DPC has failed we install a new chemical DPC by injecting a water-repellent cream into the mortar.

Why does the wall need replastering?

Rising damp carries ground salts into the plaster. Those salts attract moisture from the air, so the wall can stay damp and blister even after a new DPC is installed. Replastering with a salt-resistant system removes the contaminated plaster and gives you a sound surface to decorate.

How long after damp proofing can I decorate?

It depends on the plaster system and how wet the wall was. Your surveyor will advise, but breathable paints are usually recommended at first while the wall finishes drying.

How long does a damp survey take?

Most residential damp surveys take between 60 and 90 minutes, depending on the size of the property and the complexity of the problem.

Is the work guaranteed?

Yes. Our damp proofing comes with a written guarantee, and for a single premium the guarantee can be protected by an Insurance Backed Guarantee (IBG).

Can I stay in my home during the work?

In most cases, yes. We work room by room, protect floors and furniture and keep dust to a minimum.

Local to you

Damp Proofing across London & the Home Counties

Choose your area for local information, the towns we cover and recent projects near you.

London Surrey Sussex Hampshire Kent Middlesex Oxfordshire Berkshire Hertfordshire Essex

Client testimonials

Tapco have just completed damp proofing my house and I can't fault the quality of their work and professionalism of their operatives. A great job from start to finish, I highly recommend them.

More kind words

What else we do

Our other services

Damp, timber and structural problems rarely come alone. Our surveyors look at the whole picture, so nothing falls through the gaps.

One specialist team, from survey to guarantee.

Not sure which you need?

Damp Proofing & Rising Damp Treatment

Experts in Damp Proofing in London and the Home Counties Since 1971