Basement Tanking & Waterproofing in London
Basements, cellars and lower-ground rooms in London are prone to water ingress because they sit below external ground level. If you’re seeing damp patches, running water, salts or flaking paint, you need a proper basement tanking / structural waterproofing system – not just another coat of masonry paint.
London Leak Repairs designs and installs basement waterproofing systems that keep water on the outside so you can use the space for storage, utilities or living accommodation.
Why waterproof a London basement?
- Stop water seeping through walls and floors
- Protect plaster and finishes from salts
- Make the room fully usable and lettable
- Add value by creating dry, usable square footage
- Reduce musty smells and mould
Our Basement Waterproofing Services
1. Basement & Cellar Survey
We assess the current structure, ground levels, existing coatings and the way water is entering. London basements are all different – some want a fully dry, habitable space, others just need a dry store – so we match the system to the use.
2. Cementitious Basement Tanking
For suitable substrates we can apply cementitious tanking (waterproof slurry) to walls and floors to form a continuous barrier. This is ideal where you want a robust, direct-applied system.
3. Cavity Drain Membrane Systems
Where a full tanked system isn’t suitable, we install cavity drain membranes that manage water behind the wall and discharge it via drainage channels and a sump/pump if required. This is a very popular option in London where water pressure or irregular substrates make direct tanking difficult.
4. Floor & Wall Joint Protection
Weak points are often wall/floor junctions, lightwells, steps and service penetrations. We detail these properly so the waterproofing is continuous.
5. Internal Replastering & Fit-Out
Once the waterproofing is complete, we can carry out specialist replastering and making good so the basement or cellar is ready for decorating or further fit-out.
Typical Basement Problems We Fix
- Water tracks running down basement walls
- Flaking / blistering paint on lower-ground rooms
- Salts showing through previous plaster
- Historic coatings failing and trapping moisture
- Water coming through after heavy rain
- Damp vaults in period London houses
Because we also do leak detection and damp proofing, we can deal with basements that have both ground moisture and plumbing/roof leaks feeding into them.
Areas We Cover
We install basement tanking and cavity drain systems across all London postcodes and nearby Home Counties (Essex, Kent, Surrey, Hertfordshire), working for homeowners, landlords, architects and developers.
FAQs – Basement Tanking in London
Is tanking permanent?
When it’s correctly specified for the structure and installed to the manufacturer’s guidance, it provides long-term protection. In some cases a maintainable cavity drain system is better – we’ll tell you which suits your basement.
Do I need a sump and pump?
If groundwater is persistent or you’re below the drain level, yes. We can supply, install and commission pumps as part of the system.
Can you waterproof part of a basement only?
Yes, we can phase works or treat specific rooms, but we’ll flag any risk of water tracking from untreated areas.
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