Description
Classi Seal Waterproofing Strip — 3.2m Pre-Cut — Self-Adhesive — Shower Trays & Baths
The Classi Seal 3.2m Waterproofing Strip is a professional self-adhesive tanking strip designed to create a reliable secondary waterproof seal between shower trays or baths and bathroom walls. The pre-cut 3.2m length is specifically sized to cover a standard UK shower tray or bath on three sides with minimal waste. Applied before installation, the flexible membrane accommodates up to 15mm of building movement and allows immediate tiling — no curing wait required. Provides far superior long-term protection compared to silicone sealant alone.
✅ Pre-cut 3.2m — ready to use. Covers a standard shower tray or bath on 3 sides (approx. 2 × 900mm sides + 1 × 700–800mm end = ~2.5–2.6m used, with trim allowance). For non-standard lengths or multiple bathrooms, see the
Classi Seal per-metre option (CS025).
Key Features
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3.2m pre-cut length — sized for standard shower tray or bath on 3 sides; no measuring or cutting from a roll
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Self-adhesive backing — pressure-sensitive; quick, clean installation
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15mm movement accommodation — flexes with building settlement without compromising the seal
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Tile immediately — no curing time required after application
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Superior to silicone alone — creates a waterproof membrane behind the tiles
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Flexible strip — conforms to shower tray and bath edges
Technical Specification
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Brand: Classi
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SKU: CS032
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EAN: 5060062840094
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Type: Self-adhesive flexible waterproofing tanking strip
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Length: 3.2 metres (pre-cut)
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Width: 100–120mm (upstand + base)
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Weight: 0.5kg
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Movement accommodation: Up to 15mm
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Adhesive: Pressure-sensitive self-adhesive backing
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Material: Flexible waterproof membrane
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Application temperature: 5°C to 35°C
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Suitable surfaces: Clean, dry, dust-free
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Coverage: Standard shower tray or bath — 3 sides
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Finish: Tile over upstand; seal base with neutral cure silicone
How It Works
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Prepare: Ensure tray or bath edges are clean, dry, and dust-free
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Apply: Remove backing and press Classi Seal firmly to the wall-facing edges of the tray or bath
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Position: Install the tray or bath — the upstand extends up the wall
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Tile: Apply tiles over the upstand immediately — no curing wait
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Seal: Apply neutral cure silicone to the bottom edge once tiling is complete
What’s Included
- Classi Seal 3.2m pre-cut waterproofing strip
Suitable For
- Standard shower tray to wall junctions — 3 sides
- Standard bath to wall junctions — 3 sides
- Wet room former edges (shorter runs)
- Bathroom renovations and new builds
- Commercial bathrooms — hotels, gyms, care facilities
Also Available
Frequently Asked Questions
Will 3.2m cover my shower tray or bath?
The 3.2m length is designed to cover a standard UK shower tray or bath on three sides — typically two long sides at approximately 900mm each and one short end at 700–800mm, totalling around 2.5–2.6m, leaving a comfortable trim allowance. For larger trays, non-standard sizes, or 4-sided installations, the per-metre option (CS025) allows you to order exactly the length you need. For larger baths and shower trays, see the Flexi-Seal 4.0m strip.
Why use a tanking strip instead of silicone alone?
Silicone sealant is the first line of defence but has limitations — building movement, settlement, and thermal expansion can cause silicone to crack or separate over time. Classi Seal provides a critical secondary barrier: a flexible waterproof membrane behind the tiles that accommodates up to 15mm of movement without failing. Even if the silicone joint cracks, the tanking strip prevents water from reaching the substrate. This dual-layer approach is considered best practice by professional bathroom installers and helps meet UK Building Regulations Part C requirements for wet areas.
Can I tile immediately after applying Classi Seal?
Yes — no curing time is required. Once the strip is applied and the tray or bath is positioned, you can tile over the upstand immediately. The base edge should be sealed with neutral cure silicone once tiling is complete.
What type of silicone should I use?
Always use neutral cure silicone (not acetic/vinegar cure). Acetic cure silicone releases acetic acid during curing which can damage the adhesive and membrane. Neutral cure silicone is widely available and is the correct choice for use with tanking strips and most bathroom materials.
What is the difference between this and the per-metre version?
This product (CS032) is a pre-cut 3.2m length — convenient for a single standard shower tray or bath installation with no measuring required. The per-metre version (CS025) is cut to your exact requirements from a 25m roll — ideal for non-standard lengths, larger enclosures, wet room perimeters, or multiple bathrooms where you want to order a specific total length.
Is professional installation required?
Classi Seal is suitable for professional bathroom fitters and competent DIY enthusiasts. Correct application is important to ensure a watertight seal — apply to clean, dry, dust-free surfaces at temperatures between 5°C and 35°C, and press firmly along the entire length. Always use neutral cure silicone for the base seal.
Can I order if the item shows as out of stock?
Yes — this product is available to order even when stock shows as zero. Please allow additional lead time and contact us on 01603 381095 to confirm availability.
