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HYDRO-BLOK VAPORBLOK Liquid Waterproofing & Vapor Tight Membrane
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At a Glance
Quick Decision Guide
Container Size
3.5 gallons
Primary Function
Waterproofing and crack isolation
Steam Shower Use
Vapor-tight protection
Crack Isolation
Up to 1/8"
Application
Roller, trowel or sprayer
Tile Readiness
Next-day application
Standards
Exceeds ANSI A118.10 and A118.12
Formula
Low-VOC, water-based
Why Choose This Product
Key Benefits
Waterproof Protection
Cures into a durable, rubber-like barrier beneath tile installations.
Steam Shower Vapor Control
Helps HYDRO-BLOK assemblies meet or exceed the required 0.5 perm rating.
Crack Isolation
Accommodates substrate cracks up to 1/8" beneath supported tile installations.
Substrate Versatility
Applies over HYDRO-BLOK components and several common tile substrates.
ANSI Performance
Exceeds ANSI A118.10 waterproofing and A118.12 crack isolation standards.
Faster Project Scheduling
Fast-drying formula supports next-day tile application.
Flexible Application
Can be applied using a roller, trowel, or sprayer.
Low-Odor Formula
Water-based, low-VOC composition supports more comfortable application.
Product Information
Product Details
About This Product
HYDRO-BLOK VAPORBLOK Liquid Waterproofing Membrane for Tile
HYDRO-BLOK VAPORBLOK is a ready-to-use elastomeric membrane that cures into a durable, rubber-like barrier beneath tile installations. It combines waterproofing, vapor-control, and crack isolation performance for shower pans, steam showers, wet areas, and other supported tile assemblies.
Vapor-Tight Protection for Steam Showers
Applied over HYDRO-BLOK shower pans and wallboards at the required wet-film thickness, VAPORBLOK helps the completed assembly meet or exceed the 0.5 perm rating required for steam showers. It supports both residential and commercial steam shower installations when used according to the applicable thickness requirements.
Elastomeric Crack Isolation Across Common Substrates
The flexible membrane provides crack isolation for substrate movement up to 1/8" and exceeds ANSI A118.12. It can be used over cement backer board, gypsum backer board, gypsum drywall, dry-pack mortar beds, concrete, and compatible HYDRO-BLOK shower components.
Ready-to-Use Application with Faster Tile Scheduling
VAPORBLOK arrives ready to apply with a roller, trowel, or sprayer. Its fast-drying formulation supports next-day tile application, while the water-based, low-VOC composition provides low-odor performance for interior shower and wet-area projects.
Specifications
Brand
HYDRO-BLOK
Part Number
HBVAPORBL35
Product Type
Liquid waterproofing and crack isolation membrane
Container Size
3.5-gallon pail
Formula
Water-based elastomeric
Cured Barrier
Rubber-like
Primary Applications
Shower pans, wet areas and steam showers
Standards
Exceeds ANSI A118.10 and A118.12
Crack Isolation
Up to 1/8"
Steam Shower Rating
Meets or exceeds 0.5 perm requirement
Application Methods
Roller, trowel or sprayer
Tile Application
Next day
VOC Level
Low VOC
Odor
Low odor
Compatible Substrates
HYDRO-BLOK components, cement and gypsum backer board, drywall, mortar beds and concrete
Coverage
122.5 to 280 sq ft per pail, depending on application and wet-film thickness
Common Questions
Frequently Asked Questions
What is HYDRO-BLOK VAPORBLOK used for?
VAPORBLOK forms a durable, rubber-like waterproofing and crack isolation barrier beneath tile. It is designed for shower pans, wet areas, steam shower assemblies, and compatible common substrates. The cured elastomeric layer helps manage water, vapor, and minor substrate cracking according to the selected application.
Which substrates are compatible with VAPORBLOK?
It can be applied over HYDRO-BLOK shower components, cement backer board, gypsum backer board, gypsum drywall, dry-pack mortar beds, and concrete. Each substrate must be suitable for the intended tile assembly and prepared according to HYDRO-BLOK instructions before the membrane is applied.
Can VAPORBLOK be used in steam showers?
Yes. When used over HYDRO-BLOK pan and wallboard systems, VAPORBLOK is designed to meet or exceed the 0.5 perm rating required for steam showers. Residential steam assemblies require 20 mil wet thickness, while commercial steam assemblies require 36 mil wet thickness.
How much coverage does a pail provide for steam showers?
At 20 mil wet thickness for residential steam showers, coverage is approximately 80 sq ft per gallon or 280 sq ft per pail. At 36 mil for commercial steam showers, coverage is approximately 45 sq ft per gallon or 157.5 sq ft per pail.
What is the waterproof membrane coverage?
General waterproof membrane coverage is approximately 45 sq ft per gallon, or 157.5 sq ft per pail, at 36 mil wet thickness. For an ANSI A118.10 waterproof membrane application at 60 mil wet thickness, coverage is approximately 35 sq ft per gallon or 122.5 sq ft per pail.
How much crack isolation does VAPORBLOK provide?
The elastomeric membrane provides crack isolation for movement up to 1/8" and exceeds ANSI A118.12. At the listed 20 mil wet thickness for crack isolation, coverage is approximately 80 sq ft per gallon, or 280 sq ft from the 3.5-gallon pail.
How is VAPORBLOK applied, and when can tile be installed?
VAPORBLOK is ready to use and may be applied with a roller, trowel, or sprayer. HYDRO-BLOK identifies it as fast drying and allows next-day tile application. Actual drying conditions and wet-film thickness should follow the current manufacturer instructions before tile is installed.
What size is available, and what type of formula does it use?
VAPORBLOK is supplied in a 3.5-gallon pail and uses a water-based, low-VOC formula with low odor. Coverage varies by the required wet-film thickness and application type, so use the steam shower, waterproofing, or crack isolation rate that applies to the project.