Survey-led sump pump installation across London
Sump Pump Installation Specialists
Basements and below-ground spaces can't rely on the structure alone to keep water out. Where groundwater pressure is high, a correctly sized sump pump is what actually removes the water your waterproofing system collects. Every installation starts with a CSSW-level survey, so the pump and drainage design match the real conditions of your property. Backed by our 20-year guarantee.
Over 30 Years
Designing and installing below-ground drainage and sump pump systems.
CSSW Qualified Surveyors
Every system is designed by a qualified surveyor, not a salesperson.
20-Year Guarantee
Written guarantee on sump pump installation and waterproofing works.
Survey Fee Deducted
The survey cost comes off the price of works if you go ahead.
What Is a Sump Pump?
A sump pump is a pump and chamber system built into the floor slab of a basement or below-ground space to remove water before it can cause flooding or damage. It's normally installed as part of a Type C (cavity drain) waterproofing system: membranes fitted to the walls and floor collect any water that gets through the surrounding structure, perimeter drainage channels carry that water to a sump chamber, and the pump then discharges it away from the property. Sump pumps can also be used as a standalone water management solution where a full membrane system isn't needed.
Because they're built into the floor and hidden from view, sump pumps let you keep the below-ground space fully usable while continuously protecting it in the background.
Correct sizing matters. A pump that's too small won't cope with heavy water ingress; one that's oversized, or badly specified, can end up doing more running than it should. Sump pumps aren't designed to run 24/7, so getting the size and design right at survey stage is what makes the system reliable long-term.
How Does a Sump Pump System Work?
Rather than working alone, a sump pump is one part of a Type C waterproofing system:
- Membranes on the walls and floor intercept moisture coming through the structure and channel it downward instead of letting it soak into the room.
- Perimeter drainage channels, usually set into the floor slab at the wall-floor joint, collect that water and carry it to the sump chamber. Channels are kept to a maximum of 25m before reaching a discharge point; larger spaces may need multiple channels or additional pumps.
- The sump chamber collects the water. Once it reaches a set level, the primary pump activates and discharges it away from the property through a pipe.
- A backup pump sits in the same chamber, set to a slightly higher float level, so the system keeps working if the main pump can't keep up or fails.
- A high-water alarm warns you if levels rise further than expected, and a battery backup keeps the pump running through a power cut exactly when stormwater ingress is most likely.
This is called a "water management system" because it doesn't try to stop every drop of water reaching the structure; it manages it safely away. Designed correctly to BS8102, it's considered a failsafe approach to below-ground waterproofing, including protection against flood-level water ingress.
Key Components of a Sump Pump System
Sump Chamber & Pump
The plastic chamber set into the floor slab, housing the primary and backup pump. Fitted with a sealed, accessible cover for servicing.
Sump chamber installation →
Perimeter Drainage Channels
Channels set at the wall-floor joint that capture water from the membrane system and direct it into the sump chamber.
Drainage channel design →
Alarms & Battery Backup
High water level alarms and battery backup units, specified under BS8102, that protect the system during power outages and alert you to any issue.
Alarm & backup systems →
For properties where gravity discharge is possible without a pump, see our basement waterproofing options. For structural water ingress in older basements and cellars, see cellar tanking.
Our Sump Pump Installation Process
CSSW Waterproofing Survey
A qualified surveyor assesses the below-ground space, hydrostatic pressure and existing drainage to determine whether a sump pump is needed and how it should be sized.
System Design & Fixed Quote
You receive a clear design chamber location, drainage layout, single or dual-pump specification and a fixed price, in line with BS8102.
Installation & Flood Testing
The sump pit is excavated (or built into a new slab), the chamber and pumps are installed and connected to drainage, and the system is flood tested and signed off before the access cover is fitted.
Not sure if you need a sump pump? A waterproofing survey will tell you whether gravity drainage is enough, or whether a pumped system is needed for your property.
How Much Does Sump Pump Installation Cost?
Costs depend on the size of the below-ground space, the number of pumps required, and the extent of drainage channelling needed. The figures below are typical UK guide prices; we always confirm a fixed price after a survey.
Backed by a 20-Year Guarantee
A correctly designed and installed sump pump system, to BS8102, is built to give lasting protection against water ingress. Our sump pump installations come with a written 20-year guarantee, giving you a clear record for the property and long-term confidence in the system.
An insurance-backed guarantee is available as an option on request. It isn't included as standard, and when taken, it can transfer to a new owner on resale, supporting your property's value.
Why Choose Advanced Damp
What Our Customers Say
The basement has stayed completely dry
"Advanced Damp surveyed our basement, explained exactly why we needed a dual sump pump system, and installed it cleanly with minimal disruption. No issues since."
Correctly sized system, no more flooding after storms
"After a previous pump failed during heavy rain, Advanced Damp resized the system properly and added a battery backup. Completely different result."
Accredited & Trusted
Sump Pump FAQs
What is a sump pump?
A sump pump is a pump and chamber system installed in the floor slab of a basement to collect and remove water, usually as part of a Type C waterproofing system. It stops water building up and causing flooding or damage in below-ground spaces.
How does a sump pump work?
Water collected by wall and floor membranes is channelled through perimeter drains into a sump chamber. Once it reaches a set level, the pump discharges it away from the property. A backup pump and high-water alarm add extra protection.
How much does it cost to install a sump pump?
Cost depends on the size of the space, the number of pumps needed, and the extent of drainage required. We provide a fixed price after a survey [see our guide prices above / contact us for a quote].
Will a sump pump stop my basement flooding?
Yes, when correctly sized and installed as part of a Type C system, a sump pump is one of the most effective ways to prevent basement flooding, including in high water tables or high hydrostatic pressure conditions.
How long does a sump pump last?
A correctly specified sump pump system is built for long-term reliable use, provided it's serviced annually. We back our installations with a written 20-year guarantee.
Do sump pumps need maintenance?
Yes. Pumps, alarms and battery backups should be serviced at least once a year to keep the system working reliably, particularly ahead of winter when water ingress is highest.
What happens if the power goes out?
Our sump pump systems include a battery backup as standard, so the pump keeps running during a power cut exactly when storm-driven water ingress is most likely.
Do I need a survey before installing a sump pump?
Yes. Pump size and drainage layout depend entirely on the water conditions at your property. A CSSW survey confirms what's needed before any work is quoted. The survey fee is deducted from the cost of work if you proceed.
Is a sump pump the same as a French drain?
No. A French drain uses gravity to carry water away where ground levels allow. A sump pump is used where gravity discharge isn't possible, actively pumping water out of the below-ground space.
Get Your Sump Pump System Properly Sized
Book a waterproofing survey and a CSSW-qualified surveyor will assess your below-ground space and give you a fixed-price design. The survey fee is deducted from the cost of work if you proceed.