---
product_id: 49495873
title: "Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm)"
brand: "w4"
price: "€ 37.58"
currency: EUR
in_stock: true
reviews_count: 12
category: "W4"
url: https://www.desertcart.hr/products/49495873-mastic-sealing-strip-grey-waterproof-butyl-seal-tape-for-roofs
store_origin: HR
region: Croatia
---

# 100% Waterproof Seal Weatherproof & Flexible Instant High Adhesion Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm)

**Brand:** w4
**Price:** € 37.58
**Availability:** ✅ In Stock

## Summary

> 💪 Seal it once, forget leaks forever!

## Quick Answers

- **What is this?** Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm) by w4
- **How much does it cost?** € 37.58 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/49495873-mastic-sealing-strip-grey-waterproof-butyl-seal-tape-for-roofs)

## Best For

- w4 enthusiasts

## Why This Product

- Trusted w4 brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **DIY-Ready & Reliable:** Perfect for quick fixes on roofs, windows, doors, and campervans—no pros needed.
- • **Trusted by Thousands:** 4.6-star rating from 800+ users who swear by its leak-proof performance.
- • **Instant Grip, Zero Slip:** Super strong adhesion that locks in place on contact—no repositioning drama.
- • **Unbeatable Waterproofing:** Stops leaks cold with a watertight seal you can trust.
- • **Flexible Fit for Every Gap:** Pliable design molds perfectly to uneven surfaces and tricky corners.

## Overview

The W4 Grey Mastic Sealing Strip is a 32mm thick, 5-meter long butyl adhesive tape designed for waterproofing and gap filling on roofs, windows, doors, and recreational vehicles. With instant high adhesion and flexible weatherproof properties, it creates a durable, watertight seal that withstands rain and harsh conditions. Backed by a 4.6-star rating and a 1-year warranty, it’s the go-to solution for professional-grade DIY leak repairs.

## Description

Product Description The Range Grey 45mm x 5m Grey 32mm x 5m Grey 19mm x 5m White 45mm x 5m White 32mm x 5m White 19mm x 5m

Review: Does the job nicely - I used this as a base for fitting a roof fan onto my van. Very high instant adhesion on a properly clean surface. Be sure that all the joins are touching if not overlapping by a mm or so. It is pliable so you can squish these joins together. I would say make sure you have the fan base or whatever you are bonding, in the right place and position as you set it down because it grips immediately. I was really pleased with the seal this created once I screwed that fan in. I had to wait 24hrs until I applied the sikaflex bead around the edge and it rained overnight. Zero leakage! That filled me with confidence that once fully sealed, it would be seriously watertight. Highly recommend
Review: Works well - Brilliant product, used for levelling electric fan on my campervan roof, not a leak in sight

## Features

- Great Product

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0036KG89I |
| Best Sellers Rank | 32,953 in DIY & Tools ( See Top 100 in DIY & Tools ) 531 in Sealers |
| Brand | W4 |
| Colour | Grey |
| Customer Reviews | 4.6 out of 5 stars 802 Reviews |
| Global Trade Identification Number | 05019328000178 |
| Included Components | 1 x W4 Grey Mastic Tape Roll |
| Item Thickness | 32 Millimetres |
| Item thickness | 32 Millimetres |
| Manufacturer | W4 |
| Manufacturer Warranty Description | 1 year. |
| Material | Plastic |
| Model Number | 00017 |
| Number of Items | 1 |
| Number of items | 1 |
| Part Number | 00017 |
| Recommended Uses For Product | Waterproofing, re-bedding and waterproofing of external components on recreational vehicles and camping equipment |
| Recommended uses for product | Waterproofing, re-bedding and waterproofing of external components on recreational vehicles and camping equipment Recommended uses for product Waterproofing, re-bedding and waterproofing of external components on recreational vehicles and camping equipment See more |
| Unit Count | 4 meter |

## Product Details

- **Brand:** W4
- **Colour:** Grey
- **Item thickness:** 32 Millimetres
- **Material:** Plastic

## Images

![Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm) - Image 1](https://m.media-amazon.com/images/I/71JksPgOMFL.jpg)
![Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm) - Image 2](https://m.media-amazon.com/images/I/71VOgnVhwmL.jpg)
![Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm) - Image 3](https://m.media-amazon.com/images/I/710ia+m-kSL.jpg)
![Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm) - Image 4](https://m.media-amazon.com/images/I/816wa3r1ntL.jpg)
![Mastic Sealing Strip Grey – Waterproof Butyl Seal Tape for Roofs, Windows, Doors & Caravans, Flexible Weatherproof Adhesive Strip for Gap Filling, Leak Repair & DIY Applications (32mm) - Image 5](https://m.media-amazon.com/images/I/710ARHxKiFL.jpg)

## Questions & Answers

**Q: Can someone please explain exactly how to use this to fix a leaky sunroof as i cant find any answers on google**
A: Had the same problem with the fan on my van. I took it off and removed all the old sealing first, gave it a good clean and then I marked the outline of the fan on the roof. I then put the sealing tape around these lines like a frame. I used 3 layers and had the edges overlapping to make sure there's not the slightest gap between. After the fan was put in place and the screws were in I sealed the outline with Sikaflex. Worked perfectly and it is 100% waterproof since. I hope this will answer your question and I also hope you understand my description.

**Q: How thick is it**
A: The grey sealing strip is 30 mm wide, 2mm thick on a roll

Eric

**Q: Is this just fora moterhome or can I use it in the house?**
A: Hi,
You can use this around the house, we have kitchen fitters using this to seat kitchen sinks and hobs down with it.

**Q: Is it supplied in black**
A: Hi,
No its not supplied in black im afraid.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Does the job nicely
*by V***D on 30 September 2024*

I used this as a base for fitting a roof fan onto my van. Very high instant adhesion on a properly clean surface. Be sure that all the joins are touching if not overlapping by a mm or so. It is pliable so you can squish these joins together. I would say make sure you have the fan base or whatever you are bonding, in the right place and position as you set it down because it grips immediately. I was really pleased with the seal this created once I screwed that fan in. I had to wait 24hrs until I applied the sikaflex bead around the edge and it rained overnight. Zero leakage! That filled me with confidence that once fully sealed, it would be seriously watertight. Highly recommend

### ⭐⭐⭐⭐⭐ Works well
*by F***1 on 23 October 2025*

Brilliant product, used for levelling electric fan on my campervan roof, not a leak in sight

### ⭐⭐⭐⭐ Super sticky sealant!
*by P***. on 7 April 2024*

This is the best you can buy and does the job really well provided the surfaces have been properly cleaned. Very sticky and waterproof, this is motorhome maker's go-to choice.

## Frequently Bought Together

- W4 Mastic Sealing Strip for Caravans & Motorhomesmm – Grey 32mm Weatherproof Sealant for Overlap Joints, Awning Rails, Roof-Lights, Window Surrounds & External Trims, Durable & Easy to Apply
- Sika Sikaflex-522 Caravan And Motorhome Adhesive Sealant – Weather And Mould Resistant – White – 300ml
- Caravan Roof Vent Fan, RV Air Vent Ventilation with Rain Sensor, Automatic Level Permanent Reversible Fan 12V for RV Motorhome (14" Black Translucent- Air Max Ultra Quiet-12 volt Fan)

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**Shop now:** [https://www.desertcart.hr/products/49495873-mastic-sealing-strip-grey-waterproof-butyl-seal-tape-for-roofs](https://www.desertcart.hr/products/49495873-mastic-sealing-strip-grey-waterproof-butyl-seal-tape-for-roofs)

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*Product available on Desertcart Croatia*
*Store origin: HR*
*Last updated: 2026-07-06*