Basements in Dhaka and other cities of Bangladesh are now used for car parking, generators, pump rooms, storage and even shops. But a basement sits below the ground, surrounded by soil that stays wet for much of the year. Without proper basement waterproofing, water seeps in through walls, floors and joints, damaging the structure and everything stored inside.
Why Basements in Bangladesh Leak
- High groundwater: In many areas the water table rises close to the surface during the monsoon, pressing water against basement walls and floors.
- Hydrostatic pressure: Water in the soil pushes on the structure and forces its way through any weak point.
- Construction joints: Joints between the raft, walls and slabs are common leak paths if not sealed properly.
- Cracks: Shrinkage and settlement cracks let water through.
- Pipe and cable openings: Penetrations through walls are often left poorly sealed.
- Poor concrete quality: Porous or honeycombed concrete absorbs and passes water.
Signs Your Basement Needs Waterproofing
- Damp patches or water lines on walls
- Water seeping from floor cracks or wall-floor joints
- White salt deposits (efflorescence) on concrete
- Peeling paint or failing floor coatings
- Musty smell and high humidity
- Rust stains that may point to corroding reinforcement
Basement Waterproofing Methods
1. External (Positive-Side) Membrane
A membrane is applied on the outside of the basement walls and under the raft before backfilling, so water is stopped before it reaches the concrete. This is the best approach for new construction. Bituminous membrane waterproofing is widely used for this.
2. Cementitious and Crystalline Coatings
Cementitious coatings bond strongly to concrete and can be applied on the inside face, which makes them useful for existing basements where the outside cannot be reached. Learn more about cementitious waterproofing.
3. Integral Waterproofing Admixtures
Admixtures added to the concrete during casting reduce permeability and make the structure itself more water-resistant. See our concrete admixtures and read about waterproofing and water reducing admixture.
4. Crack Injection and Joint Sealing
Active leaks through cracks can be sealed with crack repair injection, while construction and expansion joints are treated with suitable joint sealants or waterstops.
5. Drainage and Sump Pumps
In high-water areas, perimeter drainage and a sump pump help reduce water pressure on the structure and remove any water that does enter.
Best Time to Waterproof a Basement
The cheapest and most effective time is during construction, when the outside of the walls and the underside of the raft are still accessible. For existing buildings, the dry season gives the best working conditions, so leaks can be traced and repaired before the next monsoon.
Basement Floors: Waterproof Before You Coat
Many basement car parks get an epoxy or PU floor. If the slab is not waterproofed first, moisture rising from below can make the coating blister and peel. Plan waterproofing together with car parking garage flooring for a long-lasting result.
Why Choose Fountech
Fountech has worked on waterproofing in Bangladesh since 2006, covering basements, roofs, water tanks and factory buildings. We start with a site visit, find where the water is entering and then recommend the right system. Read our ultimate guide to concrete waterproofing, see why clients choose our waterproofing service in Bangladesh, or explore all options on our waterproofing in Bangladesh page. Contact us for a basement inspection.
