About the author: Cris Bierschank
Cris is the Sustainability Manager for MAPEI Americas. As a LEED Green Associate and member of the International Living Future Institute (ILFI), he assists customers involved in sustainable projects, such as LEED and Living Building Challenge (LBC). As a member of MAPEI’s Technical Services Department, Cris helps in writing and developing the company’s training programs and technical documents, and contributes to MAPEI’s social media and technical blog. His 35 years of experience in field engineering and training include collaboration on numerous global installation projects; and during his past 13 years with MAPEI, Cris has applied his experience to the construction and flooring industry.


STACK—methodology to determine 1.) Surface preparation 2.) Product selection 3.) Acceptable installation environment & Knowledge

STACK determines degree of surface preparation and layering requirements for an installation
Have you ever wished there was a better way to ensure that you captured all of the layers required for your installation? What about the surface preparation—is it in line with the floor covering manufacturer and installation requirements?  What is STACK?  It is a guideline to determine the degree of surface preparation and subsequent layers that are required for installing various types of floor coverings, ie: resilient flooring. The following breaks STACK down into five key areas of an installation:

S: Composition and condition of substrate?  Concrete, plywood, backer board, gypsum, existing tile?  And what is the condition of the substrate?—compressive strength, deflection, profile, flatness (1/8” or 1/16” in 10 feet?), imperfections, depressions, contaminants, excessive moisture, porosity, on grade, elevated.  All of these factors coupled with the ‘type of finished covering’ (based on flooring manufacturer’s recommendations) will determine the level of surface preparation required to properly install not only the finished covering but each successive layer in the system.

T: Type of floor covering?  Tile (porcelain? Large format?), stone, glass tile, VCT, resilient flooring, rubber flooring (virgin? recycled?), carpet (tile? roll? padding?) resin/epoxy flooring, cementitious toppings, wood flooring (solid? engineered?), bamboo, cork. This includes considering the composition of the floor covering that might affect the bond or stability of the covering-backing, moisture sensitivity, coefficient of expansion (thermal stability?)  The type of ‘floor covering’ selected is really the starting point, since your finished covering will dictate WHERE can it be installed?  HOW should it be installed? WHAT are the skills required to successfully install this particular floor covering?

A: Application requirements?  WHERE will it be installed? The 'WHERE' is typically dictated by the building owner, design professional and the finished covering manufacturer–interior/exterior, residential, commercial, industrial, chemical resistance required, vehicular traffic, roof, balcony.  If it is tile, does the manufacturer have a floor 'service rating' that limits where it can be used, such as residential, light commercial or heavy commercial?  Is it rated for freeze thaw or submerged applications?

C: Installation conditions and environment?  'What are the conditions that the installation will be exposed to during its life-cycle—interior or exterior, chemical attack, water submersion (pool, fountain, water feature) extreme swings of heat or cold (cycles of freeze-thaw), humidity (exterior or interior/steam room/shower), low, moderate and high heat exposure. Are the products selected rated for the environment?

K: Knowledge and experience of application?  What is the knowledge or skill level required for the installation—involving both product & application knowledge. This is where years of experience, technique, skill, ability, and know-how all comes together to make what is on the blueprints a reality for the customer. Today’s installer uses multiple resources to stack the odds in their favor—manufacturer’s technical documents, industry guidelines and standards, manufacturer and industry trainings.  Add to this the new kid on the block, social media, which opens up a variety of networking opportunities to an installer, such as industry specific forums, blogs and peer to peer networking.  Ultimately though, since the installer is really the one who is putting the finishing touch on the project with the flooring, they must determine whether or not there are certain unforeseen risks that might not be covered when applying STACK.  This is where skill and experience come into play.
For example:  Installing solid wood flooring in a basement is possible, but is it consistent with both the manufacturer’s recommendations and Industry—is it the right floor covering for the installation? Applying the principles of STACK asks the right questions to zero in on the proper finished covering for the installation. Since solid wood is moisture sensitive, will installing it in a basement exceed the manufacturer’s recommendation for moisture content (MC)?  In this case since solid wood flooring is too moisture sensitive for a basement, substituting solid wood for engineered wood would meet the requirements—win-win scenario for the customer who wanted wood flooring in their basement while still meeting the performance criteria.

When designing an installation system, no matter what the finished covering, employing STACK- to determine 1.) Surface preparation 2.) Product selection 3.) Acceptable installation environment can be the deciding factor between a successful install and a call back!

S: Composition and condition of substrate?
T: Type of floor covering?
A: Application requirements?
C: Installation conditions and environment?
K: Knowledge Required for Application?