Damp
Rising damp assessments
Careful assessment of low-level dampness, which is frequently caused by something other than rising damp.
What the issue is
Rising damp is moisture drawn upwards through porous masonry from the ground by capillary action. It is far less common than low-level dampness generally, and a confident diagnosis needs supporting evidence rather than a meter reading alone.
Common symptoms
- Dampness concentrated within the lowest 1m of a wall
- A tide mark or salt band
- Blown plaster at skirting level
- Decayed skirting boards
- Damp that persists in dry weather
Likely contributing factors
- Absent, bridged or breached damp-proof course
- Raised external ground or paving
- Solid floor to wall junction detailing
- Internal render bridging the DPC
- Debris in a subfloor void
Conditions that may be mistaken for it
- Penetrating damp at low level
- Condensation on cold ground-floor walls
- Hygroscopic salts holding moisture
- A leaking heating pipe within the floor
How the issue should be investigated
- Establish wall construction and floor type
- Check external ground levels against internal floor level
- Locate any existing damp-proof course
- Profile moisture at varying heights
- Consider salt contamination and plaster condition
Potential treatment or repair options
- Correcting external ground levels or bridging
- Repairing defective pointing or render
- Chemical damp-proof course where confirmed as appropriate
- Replastering with a suitable damp-resistant specification
- Allowing controlled drying
When treatment may not be appropriate
- Where the pattern and evidence do not support capillary rise
- Where a bridging defect can simply be removed
- Where existing plaster is sound and only decoration is affected
Factors affecting the cost
- Linear metres of wall involved
- Whether plaster removal and replastering is needed
- Skirting and radiator removal
- Waste disposal
- Occupied working conditions
What to expect during an inspection
The surveyor will examine the affected walls internally and externally, assess the floor and wall junction, take a moisture profile and record ground levels.
Final recommendations always depend on the property, the inspection findings and the confirmed cause. Elevated readings alone do not confirm rising damp, not every mould problem requires extensive treatment, and damp-affected plaster does not always need replacing.
Frequently asked questions
Next step
Not sure which inspection you need? Start with a few questions.
Tell us what you are seeing and we will set out what is likely, what is uncertain and which inspection would answer the question. Speak to us on 0333 335 6152 if you would rather talk it through.