Heavy Rain and Damp – 7 Signs Your Home May Be Letting Water In
Periods of heavy or persistent rain can expose defects in a property that may have gone unnoticed during dry weather.
A damp patch appearing after rainfall doesn’t automatically mean you need a new damp-proof course. In many cases, the source of moisture can be much higher up or elsewhere on the outside of the building.
As we move towards autumn, this is a good time to pay attention to changes inside your property following periods of wet weather.
Here are seven signs worth investigating.
1. Damp Patches That Appear After Rain
One of the most useful clues when investigating damp is when the problem appears.
If a wall remains relatively dry during settled weather but develops a damp patch following prolonged or wind-driven rain, this may indicate moisture penetrating through the external building envelope.
Potential sources can include defective pointing, cracked render, damaged masonry, failed seals around windows or defects at roof level.
The location of the visible damp isn’t always the exact location where water is entering.
2. Damp Around Chimney Breasts
Chimney stacks are particularly exposed to the weather.
Defective pointing, damaged flashing, deteriorated chimney pots, failed flaunching and problems with unused or poorly ventilated flues can all contribute to moisture problems.
A damp patch on a chimney breast therefore shouldn’t automatically be diagnosed as rising damp.
The chimney and roof junction may need investigating.
3. Staining Around Windows and External Doors
Water staining around windows or doors can indicate problems with seals, pointing, external finishes or drainage arrangements above the opening.
In some properties, water can penetrate around the opening and travel before becoming visible internally.
Look for staining, peeling paint, damaged plaster or changes that become more noticeable following rainfall.
4. Overflowing or Leaking Gutters
Gutters have a simple but extremely important job: moving rainwater away from the building.
Blocked, damaged or poorly aligned gutters can allow large amounts of water to repeatedly run down an external wall.
Over time this can contribute to saturated masonry and internal dampness.
During rainfall, safely observing how your gutters are performing can sometimes reveal problems that aren’t obvious on a dry day.
5. Damp at the Bottom of External Walls
Low-level damp isn’t always rising damp.
External ground levels, blocked drainage, leaking rainwater pipes, defective render and repeated splashback from hard surfaces can all contribute to moisture at the base of a wall.
Correct diagnosis is important before expensive remedial work is undertaken.
Installing a chemical damp-proof course won’t repair a leaking downpipe or defective external drainage.
6. Peeling Paint, Damaged Plaster or Salts
Persistent moisture can eventually affect internal finishes.
You may notice:
- Peeling or bubbling paint
- Discoloured plaster
- Crumbling finishes
- Salt deposits
- Musty odours
- Localised mould growth
These are symptoms of a moisture problem rather than a diagnosis of its cause.
The important part of a damp inspection is establishing why the moisture is present.
7. A Damp Problem That Keeps Coming Back
If an area is repeatedly redecorated but the staining or deterioration returns, the underlying moisture source may never have been properly addressed.
Simply painting over a damp patch won’t stop water entering the building.
The cause needs to be identified first and appropriate remedial work carried out.
“independent damp and mould inspections”
Damp Isn’t Always Rising Damp
“Wirral Council also explains the differences between condensation, penetrating damp and rising damp in its guidance for homeowners and tenants.”
This is one of the most important points I make during damp inspections.
Moisture within a building can result from numerous causes, including:
- Penetrating damp
- Plumbing leaks
- Roof defects
- Chimney defects
- Condensation
- Inadequate ventilation
- Defective rainwater goods
- High external ground levels
- Bridging of the damp-proof course
- Defective masonry, pointing or render
Moisture-meter readings can form part of an investigation, but readings alone don’t establish the cause.
The property needs to be considered as a complete building.
Landlord Damp & Property Health Checks
Independent Damp & Mould Surveys – Wirral, Liverpool, Chester & North Wales
NW Snag Surveys provides independent damp and mould inspections across Wirral, Liverpool, Chester, North Wales and surrounding areas.
The aim is to identify the likely source of the moisture and provide practical recommendations for appropriate remedial action.
Inspections are carried out by Andrew Kerrigan, RPSA Tech, with over 30 years’ experience within the construction industry.
If you’ve noticed damp staining appearing or becoming worse following recent rainfall, now can be a particularly useful time to have the problem investigated.
Arrange a Damp & Mould Inspection
If you’re concerned about damp, mould or water ingress in your property, get in touch to discuss an independent inspection.
NW Snag Surveys
Andrew Kerrigan, RPSA Tech
✉️ Email Andrew