SL H715 BEST
Smart Advantages
- Fast setting and rapid curing, ready for resilient floor coverings in as little as 6 hours
- Low shrinkage formulation, minimises risk of cracking and debonding
- Excellent flow properties,ensures a smooth, level surface with minimal effort
- Hybrid technology, combines speed of cement with stability of gypsum
- Lower CO₂ footprint, up to 30% reduction compared to SL C710 BEST
- Low VOC emissions, EC1 PLUS & Blue Angel certified for improved indoor air quality
Characteristics
- Application thickness : 1 – 15 mm
- Walk on time : 2 hours
- Compressive / flexural strength : C40 / F10
- Coverage (Consumption) : 1.5 kg / mm / m²
- Water demand : 5 L per 25 kg bag
- Ready for resilient flooring after 6 hours (for up to 5mm thickness)
Why choose a hybrid self-levelling compound?
Traditional levelling products often force a compromise. Cement-based options cure quickly but may shrink and crack, while gypsum-based systems offer stability but slower drying times.
SL H715 BEST eliminates this trade-off. Its hybrid formulation provides:
- Rapid curing times
- Low internal tension
- Enhanced dimensional stability
This makes it particularly effective on challenging or unstable subfloors, especially in refurbishment projects.
Sustainability & environmental performance
SL H715 BEST has been created with sustainability in mind:
- Up to 30% lower CO₂ emissions through hybrid formulation
- Use of recycled gypsum from industrial by-products
- Very low TVOC emissions (≤60 µg/m³ after 28 days)
- Certified EMICODE® EC1 PLUS and Blauer Engel eco-label
This makes it a suitable choice for environmentally responsible flooring projects.
Application process: SL H715 BEST
Quick Application Steps (On-Site Guide)
- Prepare: Ensure substrate is clean, dry, sound and primed
- Mix: Add 5–5.25 L water per 25 kg bag, mix thoroughly
- Apply: Pour and spread (1–15 mm), use spiked roller
- Wait: Walkable in ~2 hours
- Cover: Floor coverings from 6 hours (depending on thickness)
1. Subfloor preparation
Proper preparation is essential for performance:
- Subfloors must be clean, sound, dry (<70% RH) and free from contaminants such as dust, grease, paint or adhesive residues
- Remove any weak or water-softenable materials
- Ensure tiles and existing surfaces are firmly bonded; repair or replace where necessary
- Treat cracks and joints using appropriate repair systems
- Apply a suitable primer according to the substrate type
Substrates must comply with relevant building standards before application.
2. Mixing
- Add 5 to 5.25 litres of clean, cold water into a mixing bucket
- Gradually add one 25 kg bag of compound while mixing continuously with a drill and paddle
- Mix for approximately 2 minutes until smooth and lump-free
- Allow to stand for 1 minute, then remix for 30 seconds
- Working time: approx. 30 minutes
Important: Do not overwater, as this may cause separation and affect performance.
3. Application
Apply the hybrid self-levelling compound in a single layer between 1–15 mm
- Pour onto the prepared substrate and spread using a smooth-edged steel trowel
- Use a spiked roller to remove air and improve finish
For large areas, the product can be pump applied, offering high output and efficiency.
Thanks to its excellent flow and self-levelling properties, the compound produces a smooth, seamless surface with minimal trowel marks.
4. Drying & curing
- Working time: ~30 minutes
- Walk-on time: ~2 hours
Protect the applied material from strong sunlight and draughts during curing.
Typical covering times:
- Resilient flooring (≤5 mm): ~6 hours
- Thicker layers (≤15 mm): ~12 hours
- Wood flooring: ~24 hours
5. Underfloor heating
- Switch off heating systems 48 hours before installation
- Wait 7 days after application before gradually increasing temperature
Common mistakes to avoid
- Overwatering the mix: leads to segregation and reduced strength
- Insufficient priming: can result in poor adhesion
- Applying onto weak or contaminated substrates
- Ignoring temperature conditions: outside +5°C to +25°C can affect curing
- Exposure to draughts or direct sunlight during drying
Fast Track Installation
Time-critical projects benefit from the product’s rapid drying performance:
- Resilient floor coverings: from 6 hours (≤5 mm)
- Thicker applications: from 12 hours
- Wood flooring: from 24 hours
This significantly reduces downtime and accelerates project completion without compromising quality.
Frequently Asked Questions
To use a self-levelling compound such as Bostik SL H715 BEST, the substrate must first be properly prepared, clean, sound and primed. The mixed compound is then poured onto the floor and spread evenly using a trowel. Its high flow properties allow it to level itself, creating a smooth and even surface ready for floor coverings. See the product page for the exact application.
Bostik SL H715 BEST is laid by pouring the mixed material onto the prepared subfloor at a thickness between 1 mm and 15 mm. The compound is spread with a smooth-edged trowel and finished with a spiked roller to remove air and ensure a uniform surface. It can be applied manually or by pump for larger areas. Contact your local Technical team for specifics on the best approach for your project. Contact us here.
A self-levelling compound like Bostik SL H715 BEST offers fast drying performance. It can typically accept foot traffic after approximately 2 hours, with floor coverings such as resilient materials installed from around 6 hours depending on thickness and conditions. Check the TDS for the precise information or contact your local technical team.
Bostik SL H715 BEST is designed for internal floor preparation and is not described as a waterproofing product. Subfloors must be dry and, where required, protected with a suitable damp-proof membrane before application. For Bostik’s waterproofing range visit this page.
Bostik SL H715 BEST is intended for use on internal floors only, including both renovation and new build applications. It is not specified for external use. For self-levelling compounds that can be used outside Bostik recommends the SL C980 XPS. SL C740 FIBER MAXI can also be used for exterior uses but needs to be covered afterwards.
To mix a self-levelling compound such as Bostik SL H715 BEST, add 5 to 5.25 litres of clean water to a mixing container, then gradually add the powder while mixing with a drill and paddle. Mix until smooth, allow it to rest briefly, then remix before application. The mixture remains workable for approximately 30 minutes.
With Bostik SL H715 BEST, the surface can typically be walked on after approximately 2 hours under standard conditions, allowing for faster project progression.
The required quantity of self-levelling compound depends on the application thickness and floor area. Bostik SL H715 BEST has a consumption rate of approximately 1.5 kg per mm per square metre, which can be used to calculate total material requirements.
