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Black mould on a window reveal above a window covered in condensation

Damp advice

Understanding damp before you spend money on it

Rising damp, penetrating damp and condensation look similar and need completely different work. Getting that wrong is how people end up paying twice.

The three types

Rising, penetrating and condensation

Almost every damp problem in a North East home is one of these three, or a combination of two of them. This is how to tell them apart before anyone quotes you.

A brown tidemark of rising damp staining the plaster low down on an internal wall

Rising damp

What it is
Groundwater drawn up through the base of a wall because the damp proof course has failed or was never fitted.
How to spot it
A tidemark rising from the skirting to roughly a metre, blown plaster low down, and white salt deposits. It affects the bottom of the wall, not the top.
What fixes it
A new chemical damp proof course injected into the mortar, then salt resistant replastering. External ground levels and gullies are checked at the same time.
Rainwater staining running down a brick wall below a leaking gutter

Penetrating damp

What it is
Rainwater getting in through the fabric of the building, for example a cracked gutter, failed pointing, a leaking downpipe or defective flashing.
How to spot it
One patch in one place rather than a band across the wall, often worse after heavy rain, and frequently at high level or beside a chimney.
What fixes it
Repair the defect that is letting water in, then make good inside. The survey checks gutters, downpipes, pointing and flashings to find the source.
Black mould spotting on a window reveal caused by condensation

Condensation

What it is
Moisture produced inside the property, from cooking, washing and drying clothes, settling on cold surfaces.
How to spot it
Black mould on window reveals, ceiling corners and behind furniture, plus water on the glass in the morning. Worst in winter.
What fixes it
Treat the mould, then improve ventilation and reduce humidity, usually with extraction or a positive input ventilation unit.

Symptom checker

What you can see, and what it usually means

None of this replaces a survey, but it will tell you roughly what you are dealing with. If you would rather just ask, call 0191 676 7900.

  • A tidemark rising up the wall

    A brown or yellow band above the skirting, with paint or plaster lifting along it.

    Likely rising damp

    See the service
  • Black spots and streaming windows

    Black speckling on window reveals, ceilings and behind wardrobes, with water on the glass each morning.

    Likely condensation

    See the service
  • One damp patch that never dries

    A single patch in one place, often near a gutter, downpipe or chimney, that stays dark after rain.

    Likely penetrating damp

    See the service
  • Soft, spongy or cracked timber

    Skirting, a door frame or a floorboard that gives way when pressed, sometimes with a musty smell.

    Likely timber decay

    See the service
  • Small round holes in floorboards

    Neat holes a couple of millimetres across, sometimes with fine dust beneath them.

    Likely woodworm

    See the service
  • Horizontal cracks in the brickwork

    Cracking that runs along the mortar courses outside, often repeating up the wall.

    Likely wall tie corrosion

    See the service

Questions

Common questions about damp work

Costs, guarantees, reports for lenders, and how long the work takes.

Landlords and agents

Damp and mould in rented property

Since the Social Housing (Regulation) Act and the wider attention on damp and mould, tenant reports need dealing with properly rather than with a coat of paint. We survey, report and treat, and provide the documentation you need on file.

Worried about damp in your property?

Book a free survey and we will tell you what is causing it, what needs doing and what it will cost, in writing. No pressure, no jargon, and nothing priced before the cause is confirmed.