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DWP
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Damp Proofing London

Rising damp, penetrating damp and condensation, correctly diagnosed and properly treated. We fix the cause, not the symptom alone, across London's homes and period properties.

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Diagnosis first — treatment second

Damp is one of the most misdiagnosed problems in London housing. Too often, someone sells a new damp-proof course when the real culprit is a leaking gutter, a bridged cavity or condensation. Treating the wrong cause is expensive and rarely works.

Because the cause decides the cure, we start every job by identifying what type of damp you have and where the moisture comes from. Only then do we recommend a treatment. That might be a new chemical DPC, fixing an ingress point, specialist replastering or better ventilation.

For example, rising damp climbs from the ground through porous brick, while penetrating damp enters through the wall from outside. Condensation forms when warm, moist air meets a cold surface. Each cause needs a different remedy, and therefore a correct diagnosis comes first.

The result is a genuine, lasting fix, whereas a cover-up would reappear in a year. However, if we need a closer look, our damp survey gives you a written report. For below-ground moisture, see our basement waterproofing service.

Our treatments cover the full range. A chemical DPC stops rising damp in the wall base. Membranes and specialist plaster deal with salts and moisture higher up. Meanwhile, we advise on gutters, air bricks and ventilation, since these often cause the trouble.

Period homes need extra care. Old brick and lime plaster must breathe, so the wrong product can trap water. For this reason, we pick materials that suit the building. You then get a written guarantee on the work.

Signs of a damp problem

  • Tide-marks or staining low down on internal walls
  • Peeling paint, blown plaster or crumbling skirting
  • Black mould in corners, on ceilings or around windows
  • A persistent musty smell in a room or hallway
  • Cold, damp-feeling walls that never seem to dry
  • Salt deposits (efflorescence) on masonry or plaster

How We Treat Damp

A methodical process that gets to the root cause and fixes it for good.
01

Diagnose the cause

A damp survey identifies whether the problem is rising, penetrating or condensation damp — because the wrong treatment wastes money.
02

Treat at source

We install a new chemical DPC, resolve the ingress point or address ventilation, depending on the true cause.
03

Remove & replaster

Salt-contaminated plaster is removed and replaced with a specialist replastering system that resists further damp.
04

Protect & guarantee

Finishes are made good and you receive a written guarantee on the treatment carried out.
Correct Diagnosis
We fix the cause, not the symptom.
Free Survey
Written report and fixed quote.
Guaranteed
Written guarantee on treatment.

Damp Proofing FAQs

How do I know if I have rising damp or penetrating damp? +
Rising damp usually shows as a tide-mark up to about a metre from the floor, often with salt staining. Penetrating damp appears as localised patches linked to a defect such as a leaking gutter or bridged cavity, and can appear at any height. Condensation shows as surface mould in cold spots. A survey confirms the true cause before any treatment.
What causes rising damp and how is it treated? +
Rising damp occurs when ground moisture travels up through masonry because the damp-proof course has failed or is absent. We treat it by installing a new chemical damp-proof course — injecting a water-repellent cream into the mortar bed — then removing salt-contaminated plaster and replastering with a suitable system.
Does my Victorian house need a new damp proof course? +
Not always. Many older London homes are wrongly diagnosed with rising damp when the real problem is penetrating damp, condensation or a bridged DPC. We investigate properly first and only recommend a new DPC where it's genuinely needed.
How do I stop condensation and mould? +
Condensation is a ventilation and heating issue rather than water ingress. We identify the cause and recommend practical measures — improved ventilation, insulation or targeted treatment — to control moisture and prevent black mould returning.

Damp Proofing Across London

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Get Your Damp Diagnosed

Book a free damp survey and get an honest diagnosis with a fixed quotation. Because the survey comes first, you pay only for what you need.

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