My shopping cart
Your cart is currently empty.
Continue ShoppingBostik SL-Gyp
- $39.99
Bostik SL-Gyp
- $39.99
Hybrid Gypsum-Based Self-Leveling Underlayment
Bostik SL-Gyp™
A premium hybrid gypsum and cement-based self-leveling underlayment designed for challenging substrates, radiant floor systems, renovation work, and new construction.
SL-Gyp™ combines smooth flow, rapid strength gain, high compressive strength, and broad substrate compatibility for demanding floor-leveling applications.
Product Highlights
Material Type
Hybrid Gypsum
Gypsum and cement-based formula
Thickness
1/4"–2"
Applied neat without extension
Walkable Time
3–4 Hours
Approximate return to foot traffic
Compressive Strength
Up to 5,000 PSI
For demanding flooring applications
Product Features
Radiant Heat Compatible
Suitable for use with hydronic and electric in-floor radiant heating systems.
Flexible Installation Thickness
Can be installed from 1/4 inch up to 2 inches thick without extension.
Fast Return to Service
Walkable in approximately 3 to 4 hours, with floor coverings installable in approximately 2 days.
Exceptional Strength
Provides compressive strength up to approximately 5,000 psi for demanding floor preparation projects.
Ideal for Pumping
Offers excellent flow and consistency for professional pumping applications.
Low-Prep Applications
Suitable for projects where shot-blasting or aggressive mechanical preparation cannot be performed.
Excellent Healing Properties
Maintains healing and pour-merging properties for up to approximately 20 minutes.
Rapid Strength Gain
Fast-curing performance helps support efficient construction and renovation schedules.
Performance & Specifications
Application Performance
Application Thickness
1/4"–2" Neat
Walkable Time
Approximately 3–4 Hours
Floor Covering Installation
Approximately 2 Days
Working / Healing Time
Up to 20 Minutes
Material Specifications
Water Requirement
5 Quarts per 50 lb. Bag
Compressive Strength
Approximately 5,000 PSI
Installation Method
Pour or Pump
Environmental Contribution
May Contribute to LEED® Projects
Recommended Applications
Radiant Heating Systems
Designed for use with in-floor hydronic and electric radiant heating systems.
Distressed Gypsum Floors
Suitable for repairing and leveling damaged or distressed gypsum-based substrates.
Plywood & Lightweight Concrete
Can be installed over structurally sound plywood and approved lightweight concrete substrates.
Low-Prep Renovation Projects
Ideal for applications where aggressive mechanical surface preparation is not practical.
Mud Beds & Adhesive Residue
Suitable for use over approved mud beds and properly prepared adhesive residue.
Commercial & Residential Flooring
Designed for demanding renovation and new-construction flooring applications.
Product Image
Product Resources
Technical Data Sheet
Bostik SL-Gyp™ Technical Data Sheet
Safety Data Sheet
Bostik SL-Gyp™ Safety Data Sheet
Project Specifications
SL-Gyp™ 3-Part Specifications
Surface Preparation
Bostik Surface Preparation Sell Sheet
Application Tip: Measure the specified water amount carefully and maintain a consistent mixing and placement process to support uniform flow, leveling, and strength development.
Important: Review the current Bostik Technical Data Sheet before installation. Confirm substrate suitability, required primer, surface preparation, mixing procedure, application thickness, curing conditions, moisture requirements, and floor-covering installation times.