07710 444910

WIRRAL · MERSEYSIDE · CHESHIRE

Damp is a symptom. We diagnose the cause.

NTB is a damp proofing and plastering specialist. Every job starts with a survey: we establish which mechanism is moving water into your wall, treat that mechanism, then replaster properly afterwards.

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4.9 from 350+ reviews Usually a same-day reply

A room replastered throughout, the new render still drying, with a trowel and bucket left on the boards.

EXPERIENCE

38+ years in the building trade

GUARANTEE

30 years on all damp work

QUOTES

Free, in writing, after a survey

INSURANCE

£1m public liability

RECENT WORK

Treated, rendered, finished.

The same bay window wall replastered and finished flat.
The bay window wall before work, plaster blown and stained at skirting level.

BAY WINDOW · STRIPPED TO BRICK, TREATED, REPLASTERED · DRAG TO COMPARE

Back to the brick, then built up again.

Contaminated plaster holds the salts that draw moisture back in, so it comes off entirely. What goes back on is a salt-resistant render system, skimmed flat and left to dry through before anyone decorates.

A bedroom replastered throughout and left to dry.
BEDROOM, REPLASTERED THROUGHOUT
A chimney breast and both alcoves replastered.
CHIMNEY BREAST AND ALCOVES
A wall replastered up to the existing dado rail.
REPLASTERED BELOW THE DADO RAIL
A front room replastered around a leaded window.
FRONT ROOM, LEADED WINDOW
See all fourteen →

DIAGNOSIS

Three mechanisms. Three different repairs.

MECHANISM 01

Rising damp

Groundwater drawn upward through masonry by capillary action, where the damp proof course has failed or was never installed.

SIGNATURE

A tide mark up to roughly a metre, salt bloom on the plaster, worst at skirting level, present year round.

MECHANISM 02

Penetrating damp

Water crossing the wall laterally through a defect in the fabric: pointing, render, gutters, a bridged cavity, raised ground levels.

SIGNATURE

Patches that darken after rain and dry back between, often high on the wall or alongside a downpipe.

MECHANISM 03

Condensation

Moisture produced inside the building meeting a surface cold enough for it to condense on. A ventilation problem, not a masonry one.

SIGNATURE

Black spot mould in corners, behind furniture and on window reveals. Markedly worse through winter.

Reading one for another is why damp comes back after it has been "fixed". The survey comes first, and it decides everything after it.

METHOD

One corner, four stages.

Damp staining and salt bloom at the base of a plastered wall. The same wall stripped back to bare brickwork. Membrane board fixed across the treated brickwork. The finished wall, skimmed flat and drying out.

01 / 04 · DAMP IDENTIFIED

WHAT WE DO

Damp proofing, and the plastering that follows it.

Nine things, in the order they usually come up. All of them start from the same place: establishing the mechanism before specifying a repair.

01

Rising damp treatment & DPC

Groundwater rising through masonry by capillary action, where the damp proof course has failed or was never fitted. We inject a silicone-based DPC at mortar-course level, take contaminated plaster back to the brick, and replaster in a salt-resistant render system so the hygroscopic salts left in the wall cannot bloom through the new finish.

02

Penetrating damp

Water crossing the wall from outside. We trace the route: perished pointing, cracked render, a bridged cavity, blocked gutters, external ground levels sitting above the DPC. Then we repair the defect and make good internally once the wall has dried. Treatment without the repair will not hold.

03

Condensation & ventilation

Moisture generated inside the building condensing on cold surfaces. We assess where the humid air comes from and where it currently goes, then specify extraction, background ventilation or insulation. No chemical damp treatment is appropriate for condensation, and we will say so if that is what you have.

04

Plastering & re-plastering

Sand and cement render, waterproof render systems, skimming and full replastering. Plastering is half of what we do, which means damp repairs are finished by the same team rather than handed on to somebody else.

05

Basement & cellar tanking

Below-ground rooms held dry with a cementitious tanking slurry or a cavity drain membrane, chosen on water pressure and on how the room will be used. Habitable conversions are detailed differently from dry storage.

06

Timber & woodworm treatment

Damp brings decay with it. We identify wet rot, dry rot and active woodworm, cut out and replace affected timber, treat the surrounding structure, and deal with the moisture source that caused it.

07

Re-pointing & external walls

Perished mortar joints let water straight into the wall. We rake out and repoint in a mix suited to the brick or stone rather than the hardest one available, and repair render where it has blown or cracked.

08

Damp surveys & reports

A site survey with moisture readings and a written diagnosis of the mechanism at work, the repair specified and the price given before anything is booked in. Useful for homeowners, and for sales held up by a mortgage valuation.

09

General building work

NTB also carries out general building work. Where damp repairs open up into something larger, a rebuilt gable, a new floor, structural making good, it stays with one team and one point of contact.

REVIEWS

In their words.

4.9 OUT OF 5 From 350 reviews on MyBuilder, plus reviews on Google.

DAMP IN LIVING ROOM

Nigel did two jobs for me. Damp proof course in living room and insulation and plaster boards in bedroom. I am more than happy with the outcome. Nigel's work is meticulous, he is knowledgeable and trustworthy and I would highly recommend. The 30 year guarantee is also reassuring .

Lindsay, Wirral

MYBUILDER · 19 JUN 2026

WALL DAMPING

The response to our inquiry was prompt, the pricing was reasonable, the work was completed on schedule, and the site was left clean. I highly recommend NTB.

Sam, Manchester

MYBUILDER · 6 AUG 2026

DAMP PATCH BASEMENT WALL

Can't recommend Nigel enough! Came to quote for the work and started within a matter of days. He was incredibly friendly and efficient and made sure everything was clean and tidy afterwards. Thanks again!

antonella, Macclesfield

MYBUILDER · 4 AUG 2026

DAMP IN THE HALLWAY

Turned up to do quote and explained why I had rising damp and then came back a couple of days later and completed job very satisfied with the service.

Christine Kan, Liverpool

MYBUILDER · 28 JUL 2026

BEDROOM DAMP

Major issues in our bedroom, and we've tried all the other 'fixes', so called Nigel in for a quote which he did. Identified the problem straight away and proposed a fix, which we gave the go ahead. …

Pilchy 60

GOOGLE · LOCAL GUIDE · 127 REVIEWS

RISING DAMP

Very grateful to Nigel and his team for thoroughly identifying and treating a rising damp issue which had developed at our home. Professional from the outset Nigel quoted for the proposed work, booked this …

Sue Bates

GOOGLE · LOCAL GUIDE · 10 REVIEWS

Read all 350 on MyBuilder →