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Tuesday, May 21, 2024

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Expansion joints or mortar with a crack isolation membrane


I have a wall that is 11′ high by 28′ across. The tiles going on the wall are 4″x40″ and installed horizontally. Do I need to be concerned with expansion joints? This is a primed green board wall.

Should we have any expansions or should we use a mortar with a crack isolation membrane in it?

I have a message to our setting-material rep as well. Yet I am sure he will say use the expensive materials!


Every tile installation requires expansion joints. The placement and width and material used to fill the joints vary by the type and characteristics of the installation. Environmental conditions are an important consideration.

TCNA Handbook Method EJ-171 is the tile industry guide for expansion joints. There is more information in this method than I am able to recount in this email. I suggest reviewing your copy of EJ-171 to familiarize yourself with its requirements. If there is a specification professional (architect, etc.) on this job, you will notice that EJ-171 requires them to provide you with the details of where the joints should be and how they should be constructed. If you don’t have this specification in the plans you were provided, you should ask the specifier for the prints and details you need. 

– Mark Heinlein, 
NTCA Training Director

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