Protecting a Kitchen Wall from External Water Saturation in Bourne End, SL8
A damp survey and remedial treatment plan for a kitchen and conservatory at a property on Chapman Lane, addressing external ground-level water saturation with a French drain, DPC injection, and pointing remediation.
Project at a Glance
The Brief
We were asked to attend a property on Chapman Lane in Bourne End to carry out a full damp survey for the client, who had noticed flaking paint and general deterioration around the kitchen and conservatory.
A damp survey was carried out by our surveyor, Lionel Sewell FODCS, in wet weather conditions, to establish the cause of the issue and confirm whether any active moisture ingress was present before recommending treatment.
What the Survey Found
The survey found that ground levels fell away from the gravel driveway, past the side of the conservatory and along the kitchen elevation, with no surface water drainage provisions in place along either wall.
The painted masonry showed areas of peeling paint, along with notable deterioration to the pointing at low level on the kitchen wall. As this is a north-facing elevation with numerous mature trees nearby, the walls have limited opportunity to dry out naturally between periods of wet weather.
No damp proof course was identified along these elevations. The roof coverings and rainwater goods were in fair condition for the property’s age, though localised moss growth was noted, which can contribute to blocked gutters and downpipes if left unmanaged.
Internally, no mould growth or musty odours were present, and room readings of 18.5°C, 53.3% relative humidity, and an 8.8°C dew point were all within normal parameters. All accessible moisture readings to the kitchen and conservatory walls returned dry, confirmed using a pin-type Protimeter for accurate sub-surface readings rather than a surface pad device, which can be prone to false positives from humidity or condensation sitting on the wall surface.
Thermal imaging supported this, showing no evidence of moisture retention within the wall structure, with the cooler tonal variations consistent with cold weather rather than damp.
The one area of internal deterioration was localised flaking paint around two electrical socket outlets in the kitchen, where steam from a kettle and coffee machine, combined with fixed upper units restricting airflow at wall level, had led to surface condensation forming against a hygroscopic bonding-coat plaster finish.
The Diagnosis
Due to the dryness in all moisture readings on the inside of the walls, along with thermal imaging showing no concealed moisture in the wall, there was no sign of rising damp, penetrating damp, or damp caused by pipes in the house. The peeling paint in the kitchen around the sockets was caused by condensation.
The external picture told a different story. The absence of surface water drainage, combined with ground levels falling towards the property and prolonged shading from nearby trees, meant the base of the kitchen wall was being repeatedly saturated, which had already begun to affect the pointing.
Left untreated, this ongoing external saturation was assessed as the more likely long-term risk to the wall, even though no internal damp had yet developed.
The Treatment Strategy
Based on the survey findings, we recommended a three-part external and preventative approach, rather than any internal remedial ,damp proofing, since no active internal damp was present.
A French drain was recommended along the affected elevation to intercept and redirect rainwater away from the base of the walls, addressing the underlying drainage shortfall identified during the survey and reducing the moisture load reaching the foundations going forward.
Alongside this, a chemical DPC injection was recommended specifically to the kitchen walls, creating a permanent barrier against any future moisture transfer and giving the wall the best chance to dry and stay dry over the long term. Finally, pointing remediation was recommended to the area of deteriorated mortar at the base of the kitchen wall, to stop it acting as an ongoing entry point for surface water.
Internally, the client was advised to make regular use of the kitchen window during and after steam-generating activities, ensure any mechanical extraction is used consistently, and maintain steady background heating, with any redecoration around the affected sockets to be carried out using a breathable, moisture-resistant paint system once the loose material is removed.
The Treatment
The scope of works followed the recommendations set out in the survey and job sheet:
- Installing approximately 10 linear metres of French drain along the affected kitchen and conservatory elevation, connected to the identified stormwater and wastewater drainage points
- Carrying out DPC injection to approximately 6 linear metres of the kitchen walls
- Repointing approximately 1 sq.m of deteriorated mortar to the external kitchen wall
- Confirming parking was available within the property’s own driveway, avoiding the need for any additional access arrangements.
The job was scoped for completion within 3 to 4 days onsite.
The Result
The kitchen and conservatory walls are now protected from the external water saturation identified during the survey, with the French drain redirecting rainwater away from the base of the building and the newly installed DPC providing a long-term barrier against future moisture transfer. The repointed section of wall removes the localised weak point that had already begun to deteriorate. The DPC injection work carried out is backed by a 20-year guarantee.
No internal remedial damp proofing was required, and the client was advised on ventilation and redecoration steps to resolve the condensation-related paint flaking around the kitchen sockets.
Why this approach matters: the survey’s internal findings could easily have been mistaken for early rising damp, but pin-type moisture readings and thermal imaging confirmed the walls themselves were dry. That distinction meant treatment could be focused on the real cause: external water saturation from poor ground drainage, rather than carrying out unnecessary internal damp proofing works.
Damp Treatment FAQs
How can one distinguish rising damp from condensation?
The process involves the measurement of moisture by pin-type testing at various height and depth points as well as thermal imaging and environmental readings such as humidity and dew points. In rising damp, the pattern will show increased readings on the lower wall, while condensation will show low moisture levels within the wall but paint or plaster failure on the surface.
What is a French drain, and when should it be installed?
This is a technique that helps in the redirection of water flowing over the foundations of a property. It is very helpful, especially when the ground level around the property is high or where there are no surface water drainage facilities around the property.
Do I need a damp proof course injection if my walls are testing dry?
Not always, but where ground conditions or drainage issues are likely to increase future moisture pressure against a wall, a DPC injection can be installed as a preventative measure alongside external works, to protect the wall over the long term rather than waiting for a problem to develop.
Why was pointing repair included in the treatment plan?
Deteriorated pointing allows water to track into the wall at low level. Left unaddressed, it can undermine the effectiveness of external drainage improvements, so repairing it is usually carried out alongside French drain or DPC work rather than as a standalone job.
Do you carry out damp surveys and treatment across Buckinghamshire?
Yes. We carry out damp surveys and remedial treatment across Buckinghamshire and the wider South East. You can read more on our damp proofing page.
Planning a Damp Survey or Dealing with a Damp Problem?
Our surveyors diagnose the real cause of damp before recommending treatment, using moisture readings and a full property inspection rather than guesswork. The survey fee is deducted from the cost of work if you go ahead.
Survey carried out by Lionel Sewell, FODCS, damp surveyor at Advanced Damp. Project completed at Vineyard, Chapman Lane, Bourne End, SL8 5PB.
Sam Fitzgerald is the founder of Advanced Damp and a working damp and structural waterproofing surveyor with over 12 years of experience diagnosing and treating moisture problems in residential and commercial properties across London and the South East. He is FODCS certified (a Federation of Damp Certified Surveyor) and a member of the Federation of Damp. His hands-on work covers rising damp, penetrating damp, condensation, basement waterproofing to BS 8102, and thermal imaging surveys, and he has personally completed over 400 damp surveys across properties of every type and age. Everything he writes draws directly from jobs he has carried out. He does not write about treatments, products or causes he has not dealt with first-hand in the field.
