A Problem That Wouldn’t Go Away
Michael had been managing an office building in Addlestone for nearly seven years, and he’d always taken pride in running what he considered one of the town’s better commercial properties. The three-storey building housed a mix of small businesses – a digital marketing agency, an insurance brokerage, a couple of recruitment firms, and a small café on the ground floor that kept everyone caffeinated.
“I like to think of myself as a hands-on manager,” Michael says. “When there’s a problem, I deal with it. I don’t ignore things and hope they’ll go away.”
But the problem that started developing in late autumn was different. It wasn’t something he could see or easily identify – it was something he could smell. And so could everyone else in the building.
“It started subtly,” Michael recalls. “Maybe mid-October. A couple of people mentioned a slightly unpleasant odour in the ground floor lobby. Nothing dramatic, just a bit off. I assumed someone had tracked something in from outside, or maybe the bins needed emptying more frequently.”
He arranged for additional cleaning, had the carpets professionally shampooed, and made sure the waste was collected more regularly. For a few days, it seemed to help. But then the smell returned, stronger than before.
“By November, it was unmistakable,” Michael says, grimacing at the memory. “Sewage. That’s what it smelled like. Not all the time, but particularly after heavy rain. It would get so bad that people working on the ground floor were complaining they felt nauseous.”
“It was a dream job at first,” Julie remembers. “We had a great team, reliable clients, and the warehouse itself seemed solid. But there was this one niggling issue that kept coming up – puddles in the yard after heavy rain.”
Initially, Julie didn’t think much of it. A bit of standing water in a loading bay seemed like a minor inconvenience rather than a serious problem. But as the months passed and Britain’s weather became increasingly unpredictable, those puddles started turning into ponds.
“Last October was the wake-up call,” Julie says, her expression serious. “We had three days of torrential rain, and the water in the main loading area was ankle-deep. Drivers were refusing to reverse their lorries up to the bay because they were worried about getting stuck. We had pallets of stock sitting on the warehouse floor that we couldn’t load because the area was flooded. I was losing business, and I knew I couldn’t keep making excuses to our clients.”
The Search for Answers
Michael’s first instinct was to call in his regular maintenance contractor – a local handyman who’d helped with various issues over the years. They checked the toilets, inspected all the visible plumbing, examined the external waste pipes, and even climbed onto the roof to check the soil vent pipes.
Nothing seemed obviously wrong.
“They couldn’t find anything,” Michael explains. “Everything looked fine on the surface. The drains were flowing, there were no visible leaks, the vents were clear. But the smell was getting worse, not better.”
The situation was starting to affect his tenants seriously. The recruitment firm on the ground floor reported that candidates attending interviews were commenting on the unpleasant odour. The café owner, Tony, was particularly distressed.
“Tony called me one morning in a right state,” Michael remembers. “He said, ‘Michael, I’ve got customers asking if there’s a problem with the drains. I’m running a food business here – I can’t have people thinking my café smells like sewage.’ I could hear the panic in his voice, and I didn’t blame him. His livelihood was at stake.”
The insurance brokerage on the first floor gave Michael an ultimatum: fix the problem within the month, or they’d start looking for alternative premises when their lease came up for renewal.
“That’s when I knew I was out of my depth,” Michael admits. “This wasn’t something I could fix with air fresheners and professional cleaning. Something was fundamentally wrong, and I needed proper expertise.”
Bringing in the Specialists
A colleague in property management recommended YourDrainExperts, mentioning they’d successfully dealt with a similar mysterious smell at an Egham office building the previous year. Michael called us that afternoon.
“The woman I spoke to on the phone was reassuring,” Michael says. “She didn’t seem surprised by what I was describing at all. She said they’d dealt with plenty of cases where smells appear after rain, and that usually means there’s something going on underground. She suggested a CCTV drain survey to get to the bottom of it.”
We arranged to attend Station Court the following week. Michael met our team in the car park, where we began identifying the building’s drainage access points.
“I’d never actually thought about what was under the ground before,” Michael reflects. “You just assume it all works, don’t you? Out of sight, out of mind. But watching them prepare to send a camera down into the drains, I realized how little I actually knew about the building’s infrastructure.”
The Truth Beneath the Surface
Our engineers fed the CCTV camera into the drainage system through the main inspection chamber. Michael stood with them, watching the monitor as the camera navigated through the pipes.
“At first, everything looked okay,” Michael remembers. “Just pipes doing what pipes do. But then the camera reached a section serving the ground floor, and you could see immediately that something wasn’t right.”
The footage revealed a substantial build-up of congealed fats, oils, and food waste coating the inside of the pipes. The accumulation had created a thick, sticky layer that was reducing the pipe’s diameter significantly – not enough to cause a complete blockage, but enough to slow drainage and trap organic matter.
“The engineer explained that this was probably coming from Tony’s café,” Michael says. “Not through any fault of his – it’s just what happens when you’ve got a commercial kitchen. Fats wash down the drains, cool in the pipes, and gradually build up over time. And where you’ve got organic matter sitting in warm, damp conditions, you get bacterial growth. That’s what was causing the smell.”
But the survey revealed a second, more serious problem. Further along the drainage run, our cameras identified several cracks in the underground pipes – likely caused by a combination of age, ground movement, and the weight of vehicles in the car park above.
“When they showed me the cracks, I could actually see wastewater seeping out into the surrounding soil,” Michael says. “The engineer said this was making the smell worse because contaminated water was escaping into the ground beneath the building. After heavy rain, when the water table rose, it would force those sewage gases up through any available route – which explained why the smell was always worse after rainfall.”
The Solution
Our engineers outlined a comprehensive plan. First, high-pressure water jetting would blast away all the accumulated fats and organic matter, eliminating the source of the smell. Second, the cracked pipes would be repaired using no-dig relining technology – creating a new, seamless pipe inside the existing one without the need for excavation.
“The no-dig aspect was crucial,” Michael emphasizes. “I couldn’t have the car park dug up or access roads blocked. My tenants needed to keep operating throughout the repairs. The fact that they could fix it without major disruption was a game-changer.”
Michael approved the work immediately, and our team returned three days later to carry it out. The jetting process took most of a day, with our equipment systematically clearing years of accumulated debris from the pipes. The following day, we completed the relining work, sealing the cracks and restoring structural integrity to the damaged sections.
Fresh Air at Last
The change was immediate and undeniable. By the end of that week, the smell had completely disappeared.
“I remember walking into the building on the Monday morning after the work was completed,” Michael says, smiling at the memory. “Tony was already there, opening up the café. He caught my eye and gave me this huge grin and a thumbs up. He didn’t need to say anything – we both knew the smell was gone.”
The insurance brokerage withdrew their threat to leave. The recruitment firm reported that interviews were proceeding without embarrassing questions about the building’s plumbing. And Tony’s café returned to its usual busy state, with customers no longer greeted by unpleasant odours.
Two months later, following another period of heavy rainfall, Michael held his breath – but the smell never returned.
“The difference was night and day,” he reflects. “And what really impressed me about YourDrainExperts was how they took the time to explain everything. They showed me the footage, walked me through what they’d found, and explained exactly why the smell was happening and how their solution would fix it permanently. They didn’t just patch the problem – they solved it properly.”
Michael has since implemented a six-monthly maintenance schedule with YourDrainExperts, combining regular jetting to prevent fat build-up with periodic CCTV surveys to monitor the system’s condition.
“I learned that preventative maintenance is far cheaper than crisis management,” he says. “A few hundred pounds twice a year for drain cleaning is nothing compared to the cost of losing tenants or dealing with emergency repairs. And honestly, after that experience, I sleep better knowing the drains are being properly looked after.”
Lessons for Property Managers
This Addlestone case study highlights several important considerations for commercial property managers:
- Persistent sewage smells that worsen after rainfall typically indicate underground drainage problems
- Commercial kitchens inevitably produce fats and oils that accumulate in drainage systems over time Cracked or damaged underground pipes can leak wastewater into surrounding soil, creating odour problems that surface after rain
- CCTV drain surveys provide definitive diagnosis when surface inspections reveal nothing
- Modern no-dig repair technology allows drainage issues to be resolved without disrupting commercial operations
- Regular preventative maintenance prevents fat build-up and identifies deteriorating infrastructure before problems develop
- Addressing root causes through professional drainage repair is more effective than attempting to mask symptoms with cleaning or air fresheners
If you manage commercial property in Addlestone and are dealing with mysterious odours that seem impossible to eliminate, particularly if they worsen after rainfall, the problem almost certainly lies in your drainage system. A professional CCTV drain survey can identify the source and provide the evidence needed for effective, permanent remediation.
FAQs: Solving Mysterious Sewage Smells in Addlestone Office Buildings
There's a sewage smell in my office building that gets worse when it rains. What's causing this?
Right, this is classic drainage system behaviour, and Michael at Station Court experienced exactly the same thing.
Here’s what’s happening: somewhere in your underground drainage system, there’s either damage (like cracks in the pipes) or a build-up of organic waste, or quite possibly both. During dry weather, these problems are mostly contained underground. Unpleasant, but not making their way into your building.
Then it rains heavily. The water table rises, groundwater saturates the soil around your drains, and suddenly all those sewage gases that were sitting in the damaged pipes or around cracked sections get pushed upwards. They find their way through any available route – through the building’s drainage connections, up through the floor, wherever there’s a weakness.
It’s a bit like squeezing a sponge – the rain is putting pressure on the whole underground system, and the gases have to go somewhere. Unfortunately, that somewhere is often your building.
The fat and grease build-up makes it worse because that’s creating bacterial growth inside your pipes, which produces even more foul-smelling gases. Add water pressure from rain forcing those gases upward, and you’ve got the perfect recipe for that lovely post-rainfall sewage smell.
The good news? A CCTV survey will show exactly where the problem is – the cracked pipes, the build-up, whatever’s causing it. Once you can see it, you can fix it. Michael’s smell disappeared completely once they’d repaired the cracks and cleared out the accumulated waste.
We've tried air fresheners, professional cleaning, even had the vents checked. Why won't the smell go away?
Because you’re trying to mask a symptom rather than fix the actual problem, and I completely understand why – when you can’t see what’s causing something, you try everything you can think of, right?
Michael did exactly the same thing. Professional carpet cleaning, extra bin collections, checking all the visible plumbing – his maintenance team worked their socks off trying to sort it. And it probably did help a tiny bit, temporarily. But the smell kept coming back because none of those things addressed what was actually wrong underground.
Think of it like this: if you’ve got a dead mouse in your wall cavity, you can spray air freshener until the cows come home, but the smell’s not going away until you remove the dead mouse. Same principle here – if you’ve got cracked drains leaking sewage into the ground beneath your building, or pipes full of decomposing waste creating bacterial growth, surface-level fixes aren’t going to cut it.
I’ve spoken to so many property managers who’ve spent hundreds, sometimes thousands, on cleaning services, air purifiers, all sorts, when a few hundred quid on a CCTV survey would have shown them the real problem immediately.
The frustrating thing is you can waste months trying different things that don’t work. Michael was getting increasingly desperate, his tenants were threatening to leave, and none of his attempts were making any lasting difference. The CCTV survey was what finally gave him answers instead of just more guesswork.
Save yourself the time, money, and stress – get a camera down there and find out what’s actually going on.
Most warehouse drainage systems weren’t really designed with that kind of punishment in mind. Over time, the constant pressure causes tiny cracks to appear in the pipes. Joints between pipe sections can shift slightly. Older clay or concrete pipes might start to deform or compress.
None of this happens overnight – it’s gradual. You won’t notice it until one day you’ve got a proper problem on your hands. Maybe a section collapses during heavy rain, or those hairline cracks have spread and now you’re getting leaks into the surrounding ground.
The good news? A regular CCTV survey can spot these early warning signs – the small cracks before they become big problems. It’s much easier (and cheaper!) to reinforce a slightly damaged pipe than to deal with a collapsed drain that’s shut down your entire loading operation.
Do I need to evacuate the building or close offices while this is investigated and fixed?
No, absolutely not – and this is something that really worried Michael because he had businesses operating from the building who couldn’t afford downtime.
The CCTV survey itself is completely non-disruptive. We access your drainage system through existing manholes or inspection chambers, usually outside the building. Your tenants won’t even know we’re there. Michael watched the whole survey from the car park while his offices carried on as normal inside.
As for the actual repairs, again, it depends on what we find, but in most cases you’re looking at minimal disruption. Michael’s work took three days:
- Day one and part of two: high-pressure water jetting to clear the accumulated waste from the pipes. This is done from outside access points.
- Rest of day two and day three: no-dig relining to seal the cracked pipes. Again, all done underground through access points.
The café in his building stayed open throughout. The offices kept operating. Nobody needed to evacuate or relocate temporarily. The only thing people noticed was that the smell gradually disappeared.
The only scenario where you might need to consider temporary measures is if you’ve got a severe structural failure – like a completely collapsed drain that’s causing sewage backup into the building. But even then, we’d usually be able to contain the immediate issue and restore partial function quickly while planning permanent repairs.
Put it this way: closing your building and losing business is exactly what Michael was desperately trying to avoid, and we sorted the problem without that ever being necessary. That’s the point of modern drainage repair techniques – fix the issue without wrecking your operations.
How quickly can this type of problem be diagnosed and fixed?
From first call to problem solved? In Michael’s case, about two weeks, and that’s pretty typical for this kind of issue.
Here’s roughly how it breaks down:
Initial survey (1-3 days from contact): We can usually get out to you within a few days of your call, sometimes sooner if it’s urgent. The actual CCTV survey takes a few hours – we’re not talking days of investigation. By the end of that day, you’ll know exactly what’s wrong and what needs fixing.
Planning and quoting (1-2 days): We’ll provide you with a detailed report, explain what we found, and give you a clear quote for the remedial work. You review it, ask any questions, approve the work.
Scheduling the repairs (2-7 days): How quickly we can start depends on your availability and ours. We’ll try to schedule it ASAP, especially if it’s affecting your business. Sometimes we can start within a couple of days, sometimes it might be a week if we need to order specific materials or you need time to arrange things your end.
Actual repair work (2-5 days typically): For something like Michael’s situation – jetting to clear waste build-up and relining to seal cracks – you’re looking at a few days of work. Not weeks.
So realistically, you’re probably looking at about two weeks from “I’ve got a problem” to “problem completely sorted.” Could be faster if everything aligns, might be slightly longer if the work’s more complex than expected.
Compare that to the months Michael spent trying different unsuccessful fixes, and you can see why going straight for a proper diagnosis makes sense.
The smell itself often starts improving within days of the repair work being completed, and once those cracks are sealed and the waste build-up is cleared, it’s gone for good.
One of my tenants runs a café – could their kitchen waste be causing the problem?
Possibly, yes – and this isn’t about blaming anyone, it’s just how commercial kitchens work.
In Michael’s case, the café was definitely contributing to the problem. When you’re running a food business, fats, oils, and grease inevitably go down the drains. You can be as careful as possible with grease traps and proper waste disposal, but some amount always gets into the drainage system over time.
Once it’s in the pipes, it cools and solidifies, especially in the cooler sections further from the building. This creates a coating inside the pipes that catches other debris – food particles, organic matter, whatever else is being washed down. Over time, you get this disgusting accumulation of waste that becomes a breeding ground for bacteria. That’s what creates the smell.
But here’s the important bit: the café waste wouldn’t be causing these problems if your drainage system was in good condition. The real issue in Michael’s building was the cracked pipes. If the drains had been sound, any waste would have flowed away properly to the sewers.
The combination of waste build-up AND damaged pipes was what created the perfect storm. The waste was generating smell through bacterial decomposition, and the cracks were allowing sewage to leak into the ground, where rain would then force the gases back up into the building.
So yes, commercial kitchens can contribute to drainage issues, but they’re rarely the sole cause. Usually it’s a combination of factors, and a CCTV survey will show you the complete picture.
Once Michael’s drains were jetted clear and the cracks repaired, the café could carry on operating as normal with no more smell issues – because the drainage system could now handle what it was meant to handle.
My tenants are complaining about the smell and threatening to leave. How do I keep them on board while sorting this?
This is a tough one, and I really feel for you because Michael was in exactly this position. His insurance brokerage gave him an ultimatum, the café owner was beside himself worrying about customer perception, and the whole thing was incredibly stressful.
Here’s what worked for Michael, and what I’d recommend:
Be honest and proactive: Don’t downplay it or make excuses. Acknowledge there’s a problem, tell them you’re taking it seriously, and outline exactly what you’re doing to fix it. Michael’s tenants appreciated that he was being upfront rather than pretending everything was fine.
Give them a timeline: Once you’ve got the CCTV survey done and know what needs fixing, tell your tenants specifically what’s being done and when. “We’ve identified cracked pipes and waste build-up. The repairs are scheduled for next week and will take three days” is much more reassuring than vague promises to “look into it.”
Keep them updated: Let them know when the work’s starting, how it’s progressing, when it’s finished. Communication goes a long way toward keeping people patient.
Act quickly: The longer the smell persists, the more frustrated your tenants will become. Michael was lucky in that he addressed it before anyone actually left, but it was getting close. Don’t let it drag on for months while you try different half-measures.
Demonstrate competence: Show them you’ve brought in specialists who know what they’re doing. When YourDrainExperts showed Michael the CCTV footage and explained exactly what was wrong and how they’d fix it, it gave him confidence – and that confidence came through when he talked to his tenants.
The really good news? Once Michael’s drainage was fixed and the smell disappeared, his relationship with his tenants actually improved. The insurance brokerage even complimented him on how he’d handled it. The café owner sent him wine. They saw that when faced with a serious problem, he’d dealt with it professionally and permanently.
So yes, tenant pressure is stressful, but it’s also motivation to get the problem properly sorted rather than just limping along hoping it’ll somehow resolve itself. And once it’s fixed, your tenants will remember that you came through for them when it mattered.