RedGard for crack prevention

[Michaeljftsmith]

I'm doing a tile floor and the homeowner wants a crack prevention membrane put down. Will RedGard work good for that and what's the best way to apply it? It's about 120 ft.² floor over a concrete slab.

 

[havasu]

Yes, redgard is perfect for a crack membrane. I layed porcelain plank at a home with a huge crack. I coated 4 plank widths wide on each side of the crack, and did 2 coats. Once dry, I used a polymer thinset (Mapei) and went over the crack. 10 years later, there is no cracking and looks perfect.

 

[Michaeljftsmith]

Yes, redgard is perfect for a crack membrane. I layed porcelain plank at a home with a huge crack. I coated 4 plank widths wide on each side of the crack, and did 2 coats. Once dry, I used a polymer thinset (Mapei) and went over the crack. 10 years later, there is no cracking and looks perfect.

So he wants me to spread it on the entire 120 sq ft "just in case" if the slab were to crack. Is that ok to do?

 

[Commercial Floor Rep]

Yes, you can coat the whole floor preventatively.

BUT, you should bear in mind that ALL crack suppression systems ONLY prevent cracks in the horizontal plane and only up to their limitations for movement. I believe Redguard states up to 1/8" like most roll applied systems. If there is any vertical movement a crack suppression system will not prevent cracking.

 

[havasu]

RedGard itself recommended 4 tile widths. Yes, you can do the entire floor but as Comm'l Floor Rep says, it all depends on the movement. That stuff is pricy though.

 

[Michaeljftsmith]

Yes, you can coat the whole floor preventatively.

BUT, you should bear in mind that ALL crack suppression systems ONLY prevent cracks in the horizontal plane and only up to their limitations for movement. I believe Redguard states up to 1/8" like most roll applied systems. If there is any vertical movement a crack suppression system will not prevent cracking.

Makes sense. Thank you and Havasu for your guys' help.