---
product_id: 49049734
title: "Bostik Cempolay Ultra Strong self-levelling compound"
brand: "bostik"
price: "FREE"
currency: GBP
in_stock: false
reviews_count: 10
url: https://www.desertcart.co.uk/products/49049734-bostik-cempolay-ultra-strong-self-levelling-compound
store_origin: GB
region: United Kingdom
---

# Smooths & levels up to 20mm Fast setting in 2 hours Water & frost resistant Bostik Cempolay Ultra Strong self-levelling compound

**Brand:** bostik
**Price:** FREE
**Availability:** ❌ Out of Stock

## Summary

> ⚡ Level up your floors fast with Bostik’s ultra-strong smoothing compound!

## Quick Answers

- **What is this?** Bostik Cempolay Ultra Strong self-levelling compound by bostik
- **How much does it cost?** FREE with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/49049734-bostik-cempolay-ultra-strong-self-levelling-compound)

## Best For

- bostik enthusiasts

## Why This Product

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

## Key Features

- • **All-Weather Durability:** Waterproof and frost-resistant for reliable exterior and garage use.
- • **Rapid Ready in 2 Hours:** Get foot traffic-ready floors faster than ever—no downtime, no delays.
- • **Heavy-Duty 25kg Power Pack:** Bulk size designed for professional projects demanding strength and consistency.
- • **Versatile Surface Solution:** Ideal under ceramic tiles, natural stone, or as a final paintable wear surface indoors.
- • **Precision Leveling Up to 20mm:** Achieve perfectly smooth subfloors with thick, self-levelling coverage.

## Overview

Bostik Cempolay Ultra Strong is a 25kg cement-based smoothing compound that self-levels up to 20mm thickness, sets rapidly within 2 hours, and offers water and frost resistance. Perfect for both interior and exterior subfloor preparation, it supports heavy foot traffic quickly and can be used under tiles, stone, or as a paintable final surface.

## Description

Shop Bostik Cempolay Ultra Strong Smoothing Compound, Self-Levelling, Fast Setting, Water & Frost Resistant, 25kg. Free delivery on eligible orders of £20 or more.

Review: Great product! - I really enjoyed using this product and the instructions were excellent. 5 litres of water for the complete 25kg of powder. Stirred with a paddle mixer on my drill until smooth taking approximately 3 minutes and poured nicely. I use a spiked roller to remove any chance of air bubbles and this also did a good job of levelling so I didn’t use a trowel in the end. I left the compound overnight to set although it was ok to walk on after 4 hours. Temperature was 21° where I was working. Colour didn’t change over night. Checking the level afterwards - I was very grateful it was perfect in both directions. I did use a primer on the concrete before applying. The area is approximately 900mm by 500mm and the thickness varied from roughly 20mm to 10mm. I did choose to use screws in the floor which I levelled first as a check as I hadn’t used self levelling compound before. Very happy customer!
Review: Mix well - Did the job good stuff just didn’t order enough would use again

## Features

- Causes serious eye damage.
- May cause an allergic skin reaction.
- Repeated exposure may cause skin dryness or cracking.
- Ultra fast self smoothing compound able to withstand foot traffic in just 2 hours
- Smooths and levels up to 20mm thick
- Suitable for exterior use as an underlay
- Used to level sub floors prior to laying decorative floor coverings
- Internally can be left as a final wear surface which can be over painted

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01DIRB14U |
| Batteries Required? | No |
| Colour | Grey |
| Customer Reviews | 4.2 4.2 out of 5 stars (151) |
| Date First Available | 28 Mar. 2016 |
| Included Components | 1x Bostik Cempolay Ultra Strong, 25kg |
| Item Package Quantity | 1 |
| Item Weight | 25 kg |
| Item model number | 30812526 |
| Manufacturer | Bostik Limited |
| Material | Cement-based |
| Measurement System | Metric |
| Number of Pieces | 1 |
| Part Number | 30812526 |
| Power Source | AC |
| Product Dimensions | 46 x 39 x 12 cm; 25 kg |
| Size | 25kg |

## Images

![Bostik Cempolay Ultra Strong self-levelling compound - Image 1](https://m.media-amazon.com/images/I/61-225CLWPL.jpg)
![Bostik Cempolay Ultra Strong self-levelling compound - Image 2](https://m.media-amazon.com/images/I/71-7oZfdC9L.jpg)
![Bostik Cempolay Ultra Strong self-levelling compound - Image 3](https://m.media-amazon.com/images/I/611r-Lq2CxL.jpg)
![Bostik Cempolay Ultra Strong self-levelling compound - Image 4](https://m.media-amazon.com/images/I/613riEqidyL.jpg)
![Bostik Cempolay Ultra Strong self-levelling compound - Image 5](https://m.media-amazon.com/images/I/61p8jYYeKNL.jpg)

## Questions & Answers

**Q: Could this be used to fill in an imprint concrete driveway as the imprint is too deep and collects a lot of debris?**
A: This is more for internal levelling use. I have used it at the entrance to my garage and despite vehicles going in and out it has remained rock hard with no wear. However it was layed in hot weather and was allowed to harden over a period of 2 days without getting damp or wet.

**Q: Can this be used as a floor in a wet room?**
A: No

**Q: Can this be used to resurface exterior steps as a final product without adding slabs, tiles etc.**
A: I used it to level an outside yard in Victorian terrace. I only used about 5-10mm but 7 years pn it's still OK but doesn't get much foot traffic. I used pva glue and water mix to bond it. Not sure if this helps!

**Q: is this good for external use?**
A: Not intentionally but I dropped a splodge on a concrete slab outside several years ago (4+)  and it's still there despite more than a few jet washes

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great product!
*by D***D on 25 June 2021*

I really enjoyed using this product and the instructions were excellent. 5 litres of water for the complete 25kg of powder. Stirred with a paddle mixer on my drill until smooth taking approximately 3 minutes and poured nicely. I use a spiked roller to remove any chance of air bubbles and this also did a good job of levelling so I didn’t use a trowel in the end. I left the compound overnight to set although it was ok to walk on after 4 hours. Temperature was 21° where I was working. Colour didn’t change over night. Checking the level afterwards - I was very grateful it was perfect in both directions. I did use a primer on the concrete before applying. The area is approximately 900mm by 500mm and the thickness varied from roughly 20mm to 10mm. I did choose to use screws in the floor which I levelled first as a check as I hadn’t used self levelling compound before. Very happy customer!

### ⭐⭐⭐⭐ Mix well
*by H***. on 27 January 2020*

Did the job good stuff just didn’t order enough would use again

### ⭐⭐⭐⭐⭐ Follow the instructions and you'll get the results suggested...
*by D***D on 24 May 2021*

I used this product for levelling my garage floor thats attached to my house, ahead of getting a project car in that would be sat on wheel dolleys. I wanted something that was relatively tough , waterproof and would give a fairly level smooth finish, I wasnt disappointed with the product. Its the first time I levelled a floor as I had a bad low spot I wanted to take out, compounded with the old concrete floor being terrible finish. I learned a few things along the way prep is key, take your time (but not too much this goes off in a short while) and plan plan plan. Also do a lot of vacuuming to get rid of dust and dirt. Also make sure you get a bag more than you think you need. Firstly Prep: You tend to find high spots after you level, so its best to make sure you use a bolster to chisel any high lumps off the existing floor if its that bad before you start, then use the 'primer' stuff Bostik recommend. My garage is about 2.9m wide and a little over 5m long, I primed 98% of it, with a standard emulsion roller and paint brush and the 2.5litre bottles are enough, but only just. I used something like a 40 litre size flexi bucket, a plaster mixing paddle on a 1000w drill for mixing and mixed per instructions (dont try and know better than the instructions) to get a creamy consistency, poured it out and then used the smooth size of a tiling trowel to screed it in to hard to reach places, using a 2.4m long width of 'studwork' timber to generally screed after pouring out. I also used a spiking roller to get air out as I went. Results were generally a smooth floor, much more level than it ever was. My inexperience, doing it on my own (for the screed part) meant its not as good as it could be, but I am more than happy with the results. I used 4 bags, but should have gotten 5, as I needed to finish some last bits I couldnt get to while doing the bulk of the rest and ended up getting some of Wickes own brand version of this, the results were 'ok' but no where near as good as the Bostik product and its the same price at the time pretty much. It does take some time to dry on deeper areas and dont be surprised to see a few minor cracks if you use a heater to dry and paint the floor, if you are covering it, should be fine.

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*Product available on Desertcart United Kingdom*
*Store origin: GB*
*Last updated: 2026-05-18*