SKU: 29379351824

Bostik Cempolay Ultra Strong – 20kg - Fast-Setting Self-Levelling Compound

Sale price$33.07 Regular price$36.74
Save 10%

Pay in installments of $9.19 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 17 - Jul 22

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

Bostik Cempolay Ultra Strong – 20kg - Fast-Setting Self-Levelling CompoundHigh Strength, Fast Setting Self Levelling Compound for Interior & Select Exterior Floors Bostik Cempolay Ultra Strong is a high performance, cement based self levelling compound formulated for smoothing uneven floors prior to laying final floor coverings. With exceptional compressive strength and rapid setting properties, it is ideal for both residential and commercial environments. Suitable for application on a wide range of substrates, it is

High-Strength, Fast-Setting Self-Levelling Compound for Interior & Select Exterior Floors

Bostik Cempolay Ultra Strong is a high-performance, cement-based self-levelling compound formulated for smoothing uneven floors prior to laying final floor coverings. With exceptional compressive strength and rapid setting properties, it is ideal for both residential and commercial environments. Suitable for application on a wide range of substrates, it is compatible with underfloor heating systems and can be used for certain exterior applications.

Key Features & Benefits

  • Triple-Function: Levels, smooths, and strengthens floor surfaces in a single application
  • High Compressive Strength: ≥20 N/mm² after 28 days (EN 13813 – CT-C20-F6)
  • Fast-Setting: Foot traffic in as little as 2 hours; tile in 3 hours (under 10mm)
  • Extended Thickness: Apply from 3mm up to 20mm in one layer
  • Underfloor Heating Compatible: Suitable for warm water systems (max 27°C surface)
  • Water & Frost Resistant: Can be used in certain external environments

Product & Technical Details

  • Form: Grey, free-flowing cement-based powder
  • Bag Size: 20kg
  • Coverage:
    • Approx. 4m² at 3mm thickness per 20kg bag
    • Approx. 0.6m² at 20mm thickness
  • Mix Ratio: 4 litres clean, cold water per 20kg
  • Working Time: 15–20 minutes at 20°C
  • Foot Traffic: Approx. 2 hours
  • Drying for Tiling: 3 hours (ceramic, under 10mm), 24 hours for impervious coverings
  • Application Temp: +5°C to +27°C
  • Shelf Life: 12 months unopened in cool, dry conditions (5°C–25°C)

Suitable Substrates

  • Concrete & cement/sand screeds
  • Stone, quarry tiles & unglazed ceramic tiles
  • Calcium sulphate screeds (with specialist priming)
  • Previously levelled or primed floors

Surface Preparation & Priming

  • Ensure surfaces are clean, dry, structurally sound and free from laitance, grease, oil or dust
  • Substrate moisture should be below 75% RH (use a hygrometer)
  • Prime porous surfaces with Bostik Universal Primer (1:2 dilution)
  • Prime non-porous surfaces with neat Bostik Universal Primer

Application Instructions

  1. Mix 20kg of powder with 4L clean water to a smooth, lump-free consistency
  2. Pour onto the primed subfloor and spread using a smoothing trowel
  3. Use a spiked roller to release trapped air and finish the surface
  4. Allow to cure per thickness and environment before applying finishes

Limitations & Precautions

  • Not suitable for use on timber floors, vinyl, tarmac or weak adhesive residues
  • Do not apply if temperatures will drop below 5°C within 24 hours
  • Not intended for movement-prone or flexible substrates
  • For thick applications >10mm, dry sharp sand can be used (not for heated floors)

Standards & Compliance

  • EN 13813 Classification: CT-C20-F6
  • Compressive Strength: ≥20 N/mm²
  • Flexural Strength: ≥6 N/mm²
  • Fire Classification: Class F

Suitable for Use With

  • Ceramic, porcelain and natural stone tiles
  • Laminate, wood, carpet and vinyl (after full cure)
  • Underfloor heating systems (water-fed, not electric)

Bostik Cempolay Ultra Strong offers a professional, high-performance floor smoothing solution with rapid setting and high durability. It’s ideal for preparing surfaces in time-critical installations across domestic, commercial, and light industrial spaces.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 29379351824

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.3 ★★★★★
Based on 27 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
J
Verified Purchase
Jak
San Leandro, US
★★★★★ 5
Cost effective
Style: 8.7 sqft(8 pcs), Material Type: Aluminum 197 mil
Nice, cost effective material. It stuck nicely to the door and was fairly easy to use. The grid marks on the back made it easy to cut. I would not rank it up with other materials in sound and heat isolation, but it did cut down the overall vibrations on the door panels and I did not feel heat immediately from the floor area as i did with bare metal. If you are working with a budget and want modest improvement, this material will work well over most stock materials.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 7, 2026
C
Verified Purchase
Carter Davis
Waukegan, US
★★★★★ 5
Good value and sticks well
Style: 8.7 sqft(8 pcs), Material Type: Aluminum 197 mil, Style: 8.7 sqft(8 pcs), Material Type: Aluminum 197 mil
For $14 for 8.7 square feet, this was more than enough to cover the important parts of the trunk of my 944. You DON'T need a roller to apply this, just strong hands and a well prepped surface. I vacuumed, lightly washed, then used 90% alcohol to clean the surface before applying. I could have used more and covered every inch, but there is diminishing returns in doing so (especially on a budget, or with a lower wattage sound system in my opinion). If this stuck as well as it did for me in a 45° garage, then it should stick just fine for you too. I will say, it is a little cheap feeling, but for the price I can't complain. There is an audible difference when knocking on the panels this material is applied to. I'm not a professional though, and if you're an audiophile, there are better options (but prepare to empty your wallet). Not sure I would do an entire vehicle with this material, but it is a great supplement.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 15, 2026
M
Verified Purchase
Michelle Sayre
Los Angeles, US
★★★★★ 5
Easy to work with
Style: 8.7 sqft(8 pcs), Material Type: Aluminum 197 mil
Excellent product. Strong adhesive and foam cover with silver aluminum barrier. Easy to handle and install. Cuts with razor type cutter without problems. Has inch measurements on paper side to help with fitting. Good value for cost.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 27, 2026
C
Verified Purchase
Chris L.
New York, US
★★★★★ 4
Good value for my application
Style: 37.1 sqft(34 pcs), Material Type: Aluminum 197 mil
I wanted this product for heat and sound installation. Worked well for my application of insulating Jeep floorboards. Easy to work with. Good adhesion. I may have went for a little thicker material. But it's better than only carpet. That's what Jeeps have so it worked great for me. Good value for the money, I like the size of the squares since I needed to do a lot of trimming anyway.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 26, 2025
D
Verified Purchase
D R Chapman
Houston, US
★★★★★ 5
Good value
Style: 16.3 sqft(15 pcs), Material Type: Aluminum 197 mil
Works well in installation but recommend an aluminum foil tape to go over all seams. Seems to work well as a heat insulator. Not sure about durability UNTILL we get some years under our belts.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026

recommand products