Sikaplan® WP 1100-20 HL PVC-P Sheet Waterproofing — Basements & Tunnels
Flexible, homogeneous PVC-P sheet waterproofing membrane with integral signal layer. Engineered for the waterproofing of basements, tunnels, and below-grade structures against water ingress. Specifically formulated for hot and tropical climatic conditions — HL designation confirms suitability for UAE's 45°C+ ambient temperatures.
The yellow signal layer faces inward during installation. Any damage that penetrates to this layer is immediately visible as a colour change from grey to yellow — enabling instant on-site quality control and damage detection before concrete is cast.
Specifically formulated for hot and tropical climatic conditions. Proven dimensional stability — less than 2.0% change at +80°C for 6 hours. Tested for long-term durability including warm water immersion at 50°C for up to 8 months with tensile and elongation changes below 20%. Withstands salt-laden groundwater, high hydrostatic pressure, and continuous thermal cycling across Dubai, Abu Dhabi, and Sharjah underground and infrastructure applications.
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What is Sikaplan® WP 1100-20 HL?
Sikaplan® WP 1100-20 HL is a high-performance, flexible PVC-based sheet waterproofing membrane designed for below-ground and structural waterproofing applications — basements, tunnels, and underground structures. It is a 2.0 mm thick homogeneous membrane with an integrated signal layer, manufactured from virgin PVC-P to ensure consistent quality and long-term durability.
The membrane is loosely laid and thermally welded to form fully watertight joints, creating a continuous barrier against water ingress. The HL designation confirms suitability for sustained hot climate conditions — specifically validated for UAE ambient temperatures exceeding 45°C. Free from DEHP plasticisers. CE Marked to EN 13491 (tunnels) and EN 13967 (basement tanking), certified by notified body 1213.
Key Performance Benefits
- High resistance to ageing and long-term degradation — durable waterproofing performance
- Manufactured from virgin PVC material — consistent quality and reliability
- Free from DEHP (DOP) plasticisers — safer and more stable long-term material performance
- Integrated signal layer — enables easy detection of damage during installation and inspection
- Optimised flexibility, tensile strength, and multi-axial elongation — accommodates structural movement
- High resistance to mechanical influences including puncture and site handling stresses
- Remains flexible even at low temperatures — performance across varying climatic conditions
- Suitable for contact with acidic soft water and alkaline environments — diverse soil and groundwater
- Resistant to root penetration and microbial attack — long-term underground durability
- Can be installed on damp substrates — improves on-site flexibility and application efficiency
- Excellent hot-air weldable joints — continuous, watertight thermally welded system
- Self-extinguishing behaviour in fire
All overlaps must be fully heat-welded using calibrated Leister welding equipment. No adhesive-taped or unjointed overlaps are acceptable. Welding parameters (temperature and speed) must be established by site trials before production welding begins. Trial welds must be tested by peel and shear to confirm target weld quality.
Physical & Mechanical Properties
| Base Material | Premium virgin PVC-P (DEHP-free) |
| Thickness | 2.00 mm (–5/+10%) (EN 1849-2) |
| Mass per Unit Area | 2.56 kg/m² (–5/+10%) |
| Tensile Strength (machine) | 17.0 N/mm² ± 2.0 (ISO 527 / EN 12311-2) |
| Tensile Strength (cross) | 16.0 N/mm² ± 2.0 (ISO 527 / EN 12311-2) |
| Elongation at Break | ≥ 300% (machine and cross) (ISO 527) |
| Modulus of Elasticity | ≤ 20 N/mm² at 1–2% elongation (ISO 527) |
| Burst Strength | ≥ 80% (D = 1.0 m) (EN 14151) |
| Static Puncture Resistance | 2.35 kN ± 0.25 (EN ISO 12236) |
| Impact Resistance | Watertight at 750 mm drop / 500 g (EN 12691) |
| Long-Term Compression | Watertight at 7.0 N/mm² for 50 hours |
| Foldability at Low Temp | No cracks at –20°C (EN 495-5) |
| Reaction to Fire | Class E (EN 13501-1) |
Durability & Chemical Resistance
| Dimensional Change (Heat) | < 2.0% at +80°C / 6h (EN 1107-2) |
| Resistance to Oxidation | Elongation & tensile change ≤ 10% (120d / 80°C) (EN 14575) |
| Warm Water Immersion | Tensile & elongation change <20%; mass change <4% (50°C / 8 months) |
| Mass Change (Warm Water) | < 10% (EN 14415) (70°C / 360 d) |
| Chemical Resistance | Saturated limewash & 5–6% sulfurous acid: ≤ 20% strength reduction |
| Microbiological Resistance | Tensile & elongation change ≤ 15% (EN 12225, 16 weeks) |
| Weathering Resistance | Remaining tensile & elongation ≥ 75% (EN 12224, 350 MJ/m²) |
| Weld Shear Resistance | ≥ 6.0 N/mm — break outside seam (EN 12317-2) |
| Weld Peel Resistance | ≥ 6.0 N/mm (EN 12316-2) |
Application Parameters
| Installation Method | Loose-laid and mechanically fastened |
| Jointing | Hot-air heat welding (Leister equipment) |
| Min. Application Temp | +5°C |
| Max. Ambient Temp | +35°C |
| Damp Substrate | Acceptable |
Application Guide — UAE Site Conditions
Follow these steps to achieve a continuous, fully watertight PVC-P sheet membrane system under UAE's high temperatures, aggressive groundwater, and coastal humidity conditions.
Substrate Preparation
In-situ concrete: Surface must be steel-trowel finished, clean, sound, dry, and free from standing or running water, oils, grease, dust, and loose or friable particles. Shotcrete: Surface profile must not exceed a ratio of length to depth of 5:1, with minimum 20 cm radius at changes in profile. Any active leaks must be sealed with Sika® waterproof plugging mortar or drained with a Sika® FlexoDrain system before membrane installation proceeds.
Where surface profile is irregular, apply a fine sprayed concrete layer (minimum 3–5 cm thick, max aggregate diameter 8 mm) to achieve a suitable profile. All steel elements — girders, reinforcement mesh, anchors — must be covered with a minimum of 4 cm fine sprayed concrete before membrane installation.
Geotextile / Drainage Layer Installation
Install a polypropylene geotextile (≥ 350 g/m²) or compatible drainage layer across the full substrate area prior to membrane installation. This layer protects the membrane from substrate aggregate point loads, accommodates minor surface irregularities, and provides a consistent bedding surface for the PVC-P sheet.
Membrane Installation — Loose Lay & Mechanical Fastening
Install the Sikaplan® WP 1100-20 HL membrane loose-laid over the geotextile, unrolling in the direction of work and positioning each sheet with the specified overlap width at all longitudinal and transverse joints. Fasten the membrane mechanically at the specified centres using Sikaplan® WP Disc fasteners in accordance with the Sika Method Statement for the project.
The integral yellow signal layer must face inward (between membrane and geotextile) so that any damage caused during installation is immediately visible when viewed from the exposed surface — inspect all sheets before welding commences.
Overlap Welding — Hot Air Heat Welding
All membrane overlaps must be fully heat-welded — no unjointed or adhesive-taped overlaps are acceptable. Use calibrated hot-air welding equipment: manual Leister Triac PID, semi-automatic Leister Triac Drive, or automatic Leister Twinny S. Jointing faces must be dry and clean. Welding parameters (temperature and speed) must be established by site trials before any production welding begins. Trial welds must be tested by peel and shear to confirm target weld quality. All T-joints require special preparation — chamfer the previously fabricated weld overlap before forming the T-joint weld.
Detail Waterproofing — Corners, Penetrations & Upstands
All structural details — internal corners, external corners, pipe penetrations, waterstop junctions, and wall-slab intersections — require specific detailing per the Sika Method Statement and project drawings. The Sikaplan® WP Tape System, preformed corner pieces, and Sika Waterbar® products for construction joint waterstops form the complete detail waterproofing system integrated with the sheet membrane.
Inspection, Testing & Concrete Protection
Before any concrete is cast over the membrane, carry out a full visual inspection of all welded overlaps, fastener points, detail areas, and field membrane for damage. Use the Sikaplan® WP signal layer — any cut or abrasion that penetrates to the yellow signal layer is immediately visible. Repair all identified damage before concreting using Sikaplan® WP membrane patches and fully heat-welded perimeter welds. Where specified, install Sikaplan® WP Protection Sheets over the completed membrane before steel fixing and concreting commences.
Post-Installation Performance
The completed system provides a fully watertight, compartmentalised below-grade envelope with long-term resistance to hydrostatic pressure, aggressive groundwater chemistry, root penetration, and structural movement. Suitable for residential basement slabs and walls, commercial podium decks, metro structures, highway tunnels, infrastructure underpasses, and large-scale civil foundations across all UAE project types.
Surface Temperature
Substrate temperature above 35°C causes PVC-P softening and deformation during mechanical fastening. In UAE summer, restrict installation to early morning (before 8:00 AM) or post-sunset in all exposed areas.
Weld Trial Required
Never begin production welding without completing site trial welds first. Temperature and speed parameters vary with ambient conditions — parameters valid in winter will over- or under-weld in UAE summer heat.
Signal Layer Orientation
The yellow signal layer must always face inward. Incorrect orientation means damage during installation cannot be detected. Inspect orientation on every roll before installation begins.
Recommended System Products
Sikaplan® WP 1100-20 HL is a system product. Combine with these Highway BMT-stocked Sika components for a complete, engineered below-grade waterproofing system for UAE residential, commercial, and infrastructure environments.