Rollable Cementitious Membrane for Crack-Resistant Tile Underlayment

Solution Overview

Problem

Ceramic tiles and natural stones applied directly to wood or drywall substrates face issues with cracking and damage due to the substrates' swelling and contraction, and existing underlayment solutions like cement board are heavy, labor-intensive, and not waterproof.

Innovation Solution

A flexible membrane underlayment composed of a basemat with a hydraulic component comprising at least 50% fly ash, a water-soluble film-forming polymer, and water, providing a waterproof, strong, and flexible surface for ceramic tiles that is lightweight and easy to handle, with a thin coating that can be rolled for storage and shipping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cement board is used as underlayment, then waterproofing and stability are improved, but weight and labor intensity increase

Engineering Contradiction:

ImprovewaterproofingVSAvoidweight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the composition parameters by using fly ash (at least 50% by weight) instead of traditional cement, and incorporates polymer modifiers to achieve waterproofing with reduced density. This compositional parameter change allows the membrane to be both waterproof and lightweight simultaneously

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite material system combining hydraulic binder (fly ash), polymer modifiers, and reinforcing fibers to achieve properties that individual materials cannot provide alone - specifically waterproofing, flexibility, and reduced weight in a single integrated membrane

Inventive Principle:

Principle #40Composite materials

2Reliability

If cement board is used as underlayment, then stability is improved, but ease of operation deteriorates

Engineering Contradiction:

ImprovestabilityVSAvoidease of handling

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent employs a flexible thin film membrane that can be easily rolled and unrolled during installation. The flexibility is achieved through polymer modification and controlled thickness (0.05-0.25 inches), while stability is maintained through the hydraulic binder system and reinforcing fibers embedded in the matrix

Inventive Principle:

Principle #30Flexible shells and thin films

3Weight of moving object

If plastic sheeting is used as underlayment, then weight is reduced, but bonding surface quality deteriorates

Engineering Contradiction:

ImproveweightVSAvoidbonding surface quality

Core Design Contradiction:

Weight of moving objectVSManufacturing precision

Solution Approach 1:

The invention creates a composite material system combining hydraulic binder (fly ash), polymer modifiers, and reinforcing fibers to achieve properties that individual materials cannot provide alone - specifically waterproofing, flexibility, and reduced weight in a single integrated membrane

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The membrane provides different properties at different levels: the bulk material is lightweight and flexible for easy handling, while the surface maintains hydraulic binder characteristics that provide excellent bonding quality for tile adhesion

Inventive Principle:

Principle #3Local quality

4Productivity

If ceramic tiles are applied directly to wood or drywall, then labor is reduced, but reliability deteriorates due to cracking

Engineering Contradiction:

Improvelabor efficiencyVSAvoidcracking resistance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs a flexible thin film membrane that can be easily rolled and unrolled during installation. The flexibility is achieved through polymer modification and controlled thickness (0.05-0.25 inches), while stability is maintained through the hydraulic binder system and reinforcing fibers embedded in the matrix

Inventive Principle:

Principle #30Flexible shells and thin films

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The membrane offers excellent moisture resistance, durability, and flexibility, reducing the risk of cracking and damage from substrate deformation, while being economical and lightweight, with rapid setting and low water demand, and no shrinkage-induced cracking.

Implementation Method 1

a flexible coating applied to the basemat, the coating including a hydraulic component comprising at least 50% fly ash by weight

Methodology Applied

Scientific EffectHydration: Mineral Hydration

Implementation Method 2

a polymer comprising a water-soluble, film-forming polymer; and water

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS9067383B2Flexible and rollable cementitious membrane and method of manufacturing it

Publication Date: 2015.06.30 UNITED STATES GYPSUM CO

AI summary

In a preferred embodiment, a membrane for use as an underlayment includes a basemat, which includes at least three plies, a ply of a meltblown polymer sandwiched between two plies of spunbond polymer; and a flexible coating applied to the basemat, the coating having a cementitious hydraulic component, a polymer comprising a water-soluble, film-forming polymer; and water. The finished membrane is flexible. Another embodiment for an underlayment for use underneath ceramic tiles includes a basemat and a coating of a set hydraulic component less than ⅛″ inches thick.A method of making the flexible membrane includes assembling components including a hydraulic component, a water-soluble, film-forming polymer and water, then mixing them to form a coating. A basemat is provided onto which the coating is applied over a flexible surface or no surface. After coating at least one face of the basemat, the coating is dried to form the membrane.