TCAA Tile Talk Monthly

July 2024

Introduction to Waterproofing Methods

Written by TCAA Tile Talk Monthly Sponsor: Schluter Systems Inc.

by Kali Pharand, Schluter's Product Standards and Sustainability Coordinator

The advent of indoor plumbing ushered in waterproofing challenges for bathroom and shower areas.  Since these areas are subject to daily, repeated moisture, the appropriate waterproofing must be determined prior to embarking on a wet area project.  Making this determination requires knowledge regarding various waterproofing methods.  Three of today’s most common waterproofing methods for indoor wet areas include the use of cementitious, liquid applied, and sheet applied waterproofing products.  Read on as we explore these three techniques to provide some insight and help establish which to use for your next wet-area application.

Cementitious

Cementitious waterproofing involves applying a thin layer of waterproof cement mixture over areas that will be exposed to moisture.  It is frequently used in exterior applications, although it can be performed in interior applications as well, using a long-handled brush and rolling the cement mixture over the solid backing.  Alternatively, cement waterproofing can be applied with a flat trowel. 

Liquid Applied

Liquid applied waterproofing requires the use of a liquid-based mixture and rolling or brushing it onto applicable areas in interior and exterior applications.  There are two types of liquid mixtures – elastomeric and acrylic. 

Sheet Applied

The final waterproofing method we’ll discuss here is sheet applied.  Sheets are available in band form for seams and connections, full membrane rolls for walls and floors, and corner pieces for seams on inside and outside corners.  The membranes and bands are available to purchase in different sized rolls that fit the needs of the installation and can be cut to the appropriate size, as needed.  Sheets or bands are applied with a thin-set mortar adhesive. The consistency of the mortar depends on the application, along with the substrate or solid backing (i.e., cement, drywall, foam board).  Trowels with appropriately sized notches are available for such applications and provide convenience, minimizing any guesswork.  Typically, a 2" overlap is necessary at all connections for the membrane to function as constructed and to provide a leak-proof layer.  The full membrane sheets can be applied over surrounding walls, and any expected penetrations can be cut-out as necessary while dry fitting the membrane over the substrate or solid backing.  Any fixtures that will penetrate through the application can be treated with the appropriate sealant to provide a waterproof barrier in conjunction with the membrane.  Specialized collars are also available to address waterproofing for piping protrusions, such as shower heads and mixing valves.

Standard Updates

New updates for waterproofing standards now include an option to specify waterproofing in two ways.  The existing ANSI standard is A118.10, which does not differentiate between liquid applied or sheet applied products.  Starting in 2024, specifiers will have the option to specify A118.10 L (liquid) or A118.10 S (sheet) membranes.  There is also an option to add a ‘v’ rating to either when working with waterproofing of a steam shower, specifically.

Reducing our carbon footprint with tile: Part 4 – Building material transparency, steps 3 & 4

by Scott Conwell, FAIA, FCSI, LEED AP, Director of Industry Development, International Masonry Institute

In last article, we examined the importance of transparency in reporting building material ingredients, and how a high degree of transparency positions tile favorably among competing finish materials. We looked at the first two steps toward building material transparency: inventorying ingredients and assessing their impacts. This article, Part 4 in the series, will discuss the final two steps: disclosure and optimization. Together, these steps to transparency will aid designers in making informed decisions about material selection. TCAA contractors should have a basic understanding of material ingredient reporting and the importance of transparency so they can communicate the sustainable benefits of tile to their customers, clients, and stakeholders.

 Step 3: Disclosure

Once the inventory and assessment stages are complete, manufacturers disclose their material ingredient information to design professionals. Ideally, those design professional will place a high priority on specifying safe and sustainable materials. The disclosure manufacturers make should be done using a standardized reporting format, for example a Health Product Declaration (HPD), a Manufacturer Inventory (MI), a Declare label, or another recognized vehicle for reporting. These reports present the GreenScreen® benchmark scores for each material ingredient in a clear and standardized way.

Click here for a short video clip showing how the material ingredients are disclosed in standardized formats, making it easy for designers to specify low carbon materials like tile: https://youtu.be/tw2K5lMTukE

Step 4: Optimization

If the first three steps toward transparency in construction materials are borne by the manufacturer, the final step, optimization, is the responsibility of the design professional.

Optimization occurs when a design professional specifies materials with the most thorough level of material ingredient reporting and the least impact to environmental and human health.

LEED v4 sets forth a good example of optimization in their Material Ingredient Reporting credit. When a project uses 20 different permanently installed products from at least 5 manufacturers who report their ingredients via health product declaration (HPD) or manufacturer inventory (MI) disclosing ingredients to at least 1,000 ppm, it’s eligible for 1 point; and if at least 5 of those products from 3 manufacturers report ingredients to 100 ppm, an additional point may be achieved.

A project doesn’t necessarily need to seek certification with LEED or any other rating system to optimize materials. The most basic step to building sustainably is selecting natural and lasting materials like ceramic tile, stone, and masonry. Transparency in disclosing building ingredients keeps manufacturers accountable. Tools like the Material Ingredient Guide help unify and standardize the reporting process.

Click here for a short video clip showing how designers may optimize their material selection based on manufacturers’’ transparency in reporting material ingredients by taking advantage of the Material Ingredient Reporting credit in LEED v4: https://youtu.be/WATk7JMsJnA