Basement Waterproofing
Heavy-duty sub-structure basement waterproofing and positive-side tanking systems designed to resist aggressive groundwater salinity and high hydrostatic heads across the UAE. Backed by 17-year warranties.
Substructure Waterproofing & Hydrostatic Pressure Defense
Basements and underground structures in the United Arab Emirates are subjected to extreme geotechnical environments. High water tables—often just 1.5 to 3.0 meters below ground surface near coastal and canal districts like Dubai Marina, Business Bay, and Jumeirah—exert continuous hydrostatic pressure against subterranean walls and foundation raft slabs. Furthermore, this groundwater contains elevated concentrations of chlorides and sulfates that rapidly attack structural concrete and rebar.
IZOMATE provides comprehensive basement tanking solutions engineered according to BS 8102 (Code of practice for protection of below ground structures against water from the ground). Our systems ensure complete structural dryness, preventing dampness, fungal growth, and structural corrosion.
Positive-Side External Tanking Systems
External positive-side tanking is the most effective approach for new basement construction:
- Under-Raft Waterproofing: Installed directly over blinding concrete prior to rebar placement. Dual-layer SBS bitumen membranes or pre-applied fully bonded HDPE self-adhesive sheet membranes form a continuous mechanical bond with poured concrete, preventing lateral water migration.
- Retaining Wall Tanking: Applied to exterior retaining walls following formwork striking. Slabs are primed, double-membrane waterproofed, and immediately covered with high-impact protection boards and dimpled drainage sheets before soil backfilling.
- Waterstop Integration: Pre-installed hydrophilic swellable waterstop profiles and re-injectable hose circuits installed at all kicker joints, construction joints, and pile-head interfaces.
Remedial High-Pressure Crack Injection
For existing basements experiencing active water seepage or joint leakage, external excavation is rarely feasible. IZOMATE deploys high-pressure plural-component polyurethane (PU) injection pumps operating up to 250 bar. Hydrophobic and hydrophilic injection resins penetrate the deepest hairline cracks, reacting with moisture within seconds to form an impermeable, elastomeric seal.
Geotechnical Ground Conditions & Soil Aggressiveness in Dubai
Substructure engineering in the coastal areas of the UAE—including Dubai Maritime City, Jumeirah, Business Bay, and Dubai Creek Harbour—faces exceptionally high groundwater tables that fluctuate with tidal cycles. Marine soil strata contain high concentrations of aggressive water-soluble salts: chlorides up to 25,000 ppm and sulfates exceeding 4,000 ppm. Under natural hydrostatic pressure, these aggressive ions permeate porous structural concrete, initiating rapid oxidation of reinforcement steel (rebar rusting), concrete cover spalling, and compromised structural load capacity.
To resist this continuous electrochemical onslaught, IZOMATE substructure tanking systems comply strictly with BS 8102 (Code of practice for protection of below ground structures against water from the ground) achieving Type A (Barrier Protection) and Type B (Structurally Integral Protection) performance grades. Every system combines multi-layer elastomeric membranes, robust mechanical detailing, and comprehensive protection boards.
Substrate Preparation & Detailing Around Construction Joints
Basement water tightness relies on meticulous detailing at critical cold joints, kicker interfaces, and pile-head cutoffs:
- Blinding Concrete Preparation: Cast blinding concrete (minimum 75mm grade C20) must be smooth, uniform, and free of protruding aggregate or standing water. A continuous solvent-based penetrating primer is applied at 0.25 to 0.30 kg/m² to seal surface micro-pores.
- Pile Head Waterproofing: Pile heads are chipped down to sound concrete, exposed rebar treated with zinc-rich anti-corrosion primer, and the pile perimeter sealed with two coats of polymer-modified crystalline waterproofing slurry before capping with high-strength non-shrink grout.
- Hydrophilic Waterstops & Re-Injectable Hoses: All horizontal and vertical construction joints feature pre-installed hydrophilic bentonite/butyl rubber waterstop strips that expand up to 300% upon contact with moisture. Alongside the waterstops, perforated re-injectable hoses are embedded to permit post-construction chemical resin injection if dynamic ground settlement occurs.
- Heavy-Duty Protection Boards: Immediately following dual-layer membrane torching, 3.2mm semi-rigid rot-proof asphaltic protection boards or 8mm high-density polyethylene (HDPE) dimpled drainage sheets are installed to shield the membrane from heavy aggregate impact and tearing during soil backfilling and mechanical compaction.
Quality Assurance & Dewatering Coordination
Substructure tanking must be executed in close coordination with active site dewatering operations. Ground water levels must be continuously maintained at least 500mm beneath the lowest excavation level throughout membrane installation, steel reinforcement placement, and concrete raft curing. A pre-pour joint inspection is conducted alongside the structural consultant’s representative, logging seam bleed-out, lap alignment, and protection board coverage to guarantee zero post-handover leakage.
Multi-Layer Application Detail
Continuous, monolithic barrier applied stage-by-stage with flood test verification.
Blinding Concrete Substrate
Clean, sound blinding concrete slab free of oil, water ponding, and sharp projections.
Penetrating Bitumen Primer
High-adhesion solvent-based primer penetrating concrete pores to establish a chemical bonding key.
Heavy-Duty 4mm SBS Membrane (Layer 1)
Fully bonded torch-applied SBS modified bitumen membrane with heavy-duty polyester reinforcement.
Heavy-Duty 4mm SBS Membrane (Layer 2)
Cross-laminated second layer torch-welded with staggered seams for absolute double-barrier security.
Protection Board & Dimple Drainage Sheet
3.2mm semi-rigid asphaltic protection board or HDPE dimple sheet shielding the membrane from backfill impact.
System Specifications & Standards
Verified physical and performance parameters per official manufacturer technical data sheets (TDS).
| Property / Parameter | Technical Value | Unit | Standard / Method |
|---|---|---|---|
| Total Membrane Thickness | 8.0 (2 x 4.0) | mm | EN 1849-1 |
| Hydrostatic Water Head Resistance | > 70 | meters head | DIN 52123 |
| Tensile Strength (Transverse) | 800 ± 100 | N / 50mm | ASTM D5147 |
| Puncture Resistance (Static) | > 350 | N | ASTM E154 |
| Crack Bridging Capability | > 3.5 | mm | ASTM C1305 |
From first visit to warranty
Inspect
Site visit, moisture and surface checks, photos.
Propose
System, layer build-up, price per m² and programme.
Install
Trained crew, stage-by-stage checks, flood test.
Hand over
Completion report and written warranty.
12 to 17 Years System Warranty
Every completed project includes a signed handover certificate, inspection log, and written warranty backed by manufacturer technical data.
Frequently Asked Questions
Answers to common questions regarding specifications, installation timeline, and preparation.
What is the difference between positive side and negative side basement waterproofing?
Positive-side waterproofing is applied to the exterior face of basement walls and under the foundation raft in contact with soil and groundwater. It prevents water from entering the concrete. Negative-side waterproofing is applied from inside the basement when external excavation is impossible.
How do you handle aggressive saline groundwater in Dubai coastal areas?
We specify multi-layer SBS-modified membranes with heavy-duty non-woven polyester carriers and chemical-resistant polymer additives that resist sulfate, chloride, and hydrocarbon attack commonly found in high water-table zones.
How are basement construction joints and tie-rod holes waterproofed?
Construction and cold joints are sealed with hydrophilic swellable waterstops (which expand up to 300% upon water contact) combined with injectable re-injectable hose systems. Tie-rod sleeves are plugged with non-shrink waterproof cementitious plugs.
Can active water leaks in existing basements be stopped without excavating outside?
Yes. Active basement leaks are permanently sealed from inside using high-pressure polyurethane (PU) injection resins that react instantly with rushing water to form a dense, flexible foam barrier within concrete cracks and honeycombs.
Can basement waterproofing be applied while active dewatering is running on site?
Yes. External positive-side basement tanking requires the dewatering system to maintain groundwater levels at least 500mm below the blinding slab during primer, membrane, and raft concrete placement until the structural weight offsets hydrostatic buoyancy.
What type of protection board is recommended before backfilling basement walls?
We recommend semi-rigid asphaltic protection boards (minimum 3.2mm thickness) or dimpled HDPE drainage sheets with integrated geotextile filter fleece. These protect the membrane against sharp rock puncturing and hydrostatic soil shear during heavy mechanical backfill compaction.