Description
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✓ Pre-cut 4.0m length - the essential waterproofing solution for larger baths, shower trays and worktops
The Flexi-Seal 4.0m Waterproofing Strip is a professional-grade flexible rubber seal that creates a permanent, watertight barrier between shower trays, baths or worktops and your bathroom walls. Unlike silicone sealant alone, Flexi-Seal maintains a 100% waterproof seal even when subjected to building movement - particularly important in new builds and renovations.
Key Features & Benefits
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100% Waterproof Seal – Creates a permanent barrier that won't fail
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Flexible Rubber Construction – Accommodates building movement and settlement
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Butyl-Based Adhesive – Quick, secure installation with integrated adhesive strip
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Concealed Installation – Tiles or panels fit directly over the seal
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BS EN 28510-1 Tested – Independently tested to British and European standards
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Pre-Cut 4.0m Length – Ideal for larger baths, P-shaped baths, and full-size shower trays
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Generous Coverage – Complete coverage with material to spare
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Prevents Water Damage – Protects against leakage at vulnerable wall junctions
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Professional Grade – Essential for quality bathroom installations
Why 4.0m Length?
This generous 4.0m length is specifically designed for larger bathroom installations:
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Large Baths: Complete coverage for three sides of standard 1700mm baths with material to spare
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P-Shaped & L-Shaped Baths: Perfect for shaped baths with extended perimeters
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Full-Size Shower Trays: Ideal for 900mm, 1000mm, 1200mm shower trays (covers three sides)
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Extended Worktops: Suitable for longer bathroom vanity units and countertops
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Wet Rooms: Adequate length for larger former installations
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Reduced Waste: Right-sized for larger projects without running short
For smaller installations, consider our 2.0m or 3.2m options to minimize waste.
How Flexi-Seal Works
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Preparation: Clean and dry the edge of your shower tray, bath or worktop
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Application: Remove backing and apply Flexi-Seal to the edge using the butyl adhesive strip
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Installation: Position the tray/bath against the wall with the seal extending up the wall surface
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Tiling: Fit tiles or wall panels over the flexible rubber seal
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Sealing: Apply silicone sealant at the bottom edge for a complete waterproof system
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Protection: The flexible seal accommodates building movement without compromising the waterproof barrier
What's Included
- Flexi-Seal flexible rubber waterproofing strip (4.0 metres)
- Integrated butyl-based adhesive backing
- Installation instructions
Technical Specifications
- Manufacturer: Spajet
- Product: Flexi-Seal waterproofing strip
- Length: 4.0 metres (pre-cut)
- Width: Typically 100-120mm (upstand + base)
- Material: Flexible rubber seal
- Adhesive: Butyl-based adhesive strip
- Testing: Independently tested to BS EN 28510-1 1993
- Waterproof Rating: 100% permanent seal
- Application Temperature: 5°C to 35°C
- Installation: Apply to tray/bath edge before positioning
- Finish: Tile or panel over seal
- Coverage: Large baths, P-shaped baths, full-size shower trays, extended worktops
- Barcode: 5060134754946
- SKU: FLEXI14
Applications & Use Cases
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Large Bath Installations: 1700mm, 1800mm standard baths (three sides)
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P-Shaped Shower Baths: Extended perimeter coverage
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L-Shaped Baths: Complete sealing for shaped bath configurations
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Full-Size Shower Trays: 900mm, 1000mm, 1200mm trays
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Extended Worktops: Longer vanity units and countertop installations
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New Builds: Essential where building movement is expected
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Renovations: Upgrade existing installations with superior waterproofing
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Commercial Bathrooms: Hotels, gyms, care facilities
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Wet Rooms: Larger former edge waterproofing
Why Choose Flexi-Seal Over Silicone Alone?
Traditional silicone sealant is the first line of defence, but it has limitations. Building movement, settlement, and thermal expansion can cause silicone to crack or separate from surfaces over time. Flexi-Seal provides a critical secondary barrier that:
- Accommodates building movement without failing
- Creates a waterproof membrane behind the tiles
- Prevents water from reaching the substrate even if silicone fails
- Extends the life of your bathroom installation
- Meets and exceeds building regulations for wet areas
- Prevents costly water damage, rot, and mould growth
BS EN 28510-1 1993 Testing
Flexi-Seal has been independently tested to BS EN 28510-1 1993, the British and European standard for pressure-sensitive adhesive tapes. This certification confirms:
- Adhesive strength and reliability
- Performance under stress and movement
- Waterproof integrity
- Suitability for bathroom applications
- Compliance with building regulations
Installation Instructions
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Prepare Surface: Ensure shower tray, bath or worktop edges are clean, dry, and dust-free
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Measure & Cut: 4.0m length is pre-cut; trim if needed for your specific installation
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Remove Backing: Peel away the protective backing to expose the butyl adhesive
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Apply Strip: Press Flexi-Seal firmly onto the edge, ensuring good adhesion along the entire length
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Position Item: Install the tray, bath or worktop with the seal extending up the wall
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Tile Over: Apply tiles or wall panels over the upstand portion of the seal
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Seal Base: Once tiling is complete, apply silicone sealant to the bottom edge
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Cure: Allow silicone to cure as per manufacturer's instructions
Professional Tips
- Always use neutral cure silicone (not acetic/vinegar cure) to avoid damaging the seal
- Apply to clean, dry surfaces for maximum adhesion
- Work in temperatures between 5°C and 35°C for best results
- Press firmly along the entire length to ensure complete adhesion
- Ensure the upstand extends high enough to be covered by tiles/panels
- For P-shaped or L-shaped baths, measure the full perimeter before cutting
When Flexi-Seal is NOT Required
Important Note: Flexi-Seal is not required if using a shower tray with an integrated upstand option, as these trays already incorporate the waterproofing feature. Check your shower tray specifications before purchasing.
Building Regulations Compliance
Flexi-Seal helps ensure compliance with UK Building Regulations Part C (Site Preparation and Resistance to Contaminants and Moisture) by providing effective waterproofing in wet areas. The dual-layer approach (flexible seal + silicone) is considered best practice by professional bathroom installers and exceeds minimum requirements.
Length Comparison Guide
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2.0m Length: Ideal for compact showers (700-800mm), smaller baths, worktops
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3.2m Length: Perfect for standard shower trays and baths (covers three sides)
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4.0m Length (this product): Best for large baths, P-shaped baths, full-size shower trays - generous coverage with material to spare
Choose the length that best matches your installation to ensure complete coverage without running short.
Coverage Examples
Standard 1700mm Bath (three sides):
- Two long sides: 1700mm × 2 = 3400mm
- One short end: 700mm
- Total required: 4100mm (4.1m)
- 4.0m length provides near-complete coverage
1200mm Shower Tray (three sides):
- Two sides: 1200mm × 2 = 2400mm
- One side: 800mm
- Total required: 3200mm (3.2m)
- 4.0m length provides complete coverage with 800mm to spare
About Spajet
Spajet specializes in professional waterproofing and bathroom installation products. Their Flexi-Seal range is trusted by professional installers, bathroom fitters, and builders across the UK for reliable, long-lasting protection against water damage.
Perfect for: Professional bathroom installers, plumbers, tilers, builders, property developers, and competent DIY enthusiasts seeking reliable, tested waterproofing for larger bathroom installations that exceeds building regulations and prevents costly water damage.
🛡️ PROFESSIONAL WATERPROOFING: Pre-Cut 4.0m Strip - Save £13 🛡️
