External DPC Protection & Perimeter Drainage, Somersham PE28
A new drainage channel was run around the base of the external walls to keep groundwater off the brickwork and away from the damp-proof course underneath. Here’s a look at the work carried out at this property in Somersham.
Project at a Glance
The Job
This one came through as a completion visit at a property on The Pastures, Somersham, for customer. The scope was to install drainage protection around the outside of the property to safeguard the existing damp-proof course. Our contractor, Daniel Chapman, was out for the day to get it done.
It’s not the most dramatic job we do, but it’s an important one. Even a perfectly good damp-proof course can get bridged over time if ground levels sit too high against it, or if paving ends up channeling water straight at the base of a wall instead of away from it. Once that happens, moisture finds its way in regardless of how sound the DPC itself is. Putting in a proper drainage channel around the perimeter is one of the simplest ways to stop that ever becoming a problem.
The Work Carried Out
Daniel ran a drainage channel along the base of the external brickwork, tracking the perimeter of the property past windows, doors and around each corner, with the new paving laid right up to it.
The channel sits just below the brick line, so surface and ground water has a clear route away from the wall instead of pooling or sitting against the masonry, which is exactly the kind of thing that ends up compromising a damp-proof course from the outside.
It was a one-day job, and nothing unexpected came up along the way. The finish was left clean and tidy, with the new paving and drainage line sitting neatly against the brickwork ready for the rest of the landscaping to come together around it.
The Result
The job was completed on 13th March 2026. The customer was on site at completion, was walked around by Daniel to see the finished work, and confirmed everything had gone in as agreed, with the area left safe and tidy. It was signed off on the day and later approved by our Head Contractor.
Jobs like this tend to disappear once the paving’s down around them, but that’s really the point; it’s the kind of detail that quietly keeps a damp-proof course doing its job for years, rather than turning into a problem you only notice once it’s already inside the wall.
Perimeter Drainage & DPC FAQs
Why does a damp-proof course need external drainage protection?
A damp-proof course only works properly if it sits clear above the surrounding ground and isn’t sitting in standing or pooling water. A drainage channel keeps water moving away from the base of the wall, so the DPC doesn’t end up bridged or compromised over time.
What happens if ground levels or paving sit too close to the DPC?
If paving, soil or landscaping builds up above the level of the damp-proof course, water can bypass it altogether and track straight into the brickwork, which can lead to rising or penetrating damp showing up inside the property.
Is this the kind of thing you’d install as a preventative step, or only as a repair?
Both, really. It often goes in alongside new landscaping or paving as good practice, but just as often it’s something we recommend after a damp survey flags ground levels or poor drainage as a risk to an existing property.
How long does a job like this usually take?
It depends on the length of the run and how the property’s laid out, but a single external run like this one was done in a day. Bigger properties or trickier ground layouts can take a bit longer.
Thinking about protecting your property’s DPC?
Our qualified surveyors diagnose the real cause and give you a fixed-price quote. The survey fee is deducted from the cost of work if you go ahead.
Project completed at 2A The Pastures, Somersham, Cambridgeshire, PE28 3YX.
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.
