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02-26-2008, 09:19 PM
i installed pro-fit ledgestone tight-fit stone on hardie backer with type-n mortar---it started falling off about 28 days later----what did i do wrong

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02-26-2008, 10:31 PM
Are you using the 3/4" thick model as a brick veneer? If you are, you have used the wrong mortar.

Type N mortar is a brick mortar, not a thinset mortar. It is meant for stacking full depth bricks and concrete blocks, not adhering brick veneer to hardie backer.

Can you give us a few more details about the installation? Did you use metal lath, brick ties?

02-26-2008, 10:33 PM
Hi There ohgeeo1,

besides what Colin said the HardiBacker might have sucked the water out
of the mortar and made it not cure properly. that could also be a factor.

Have a great day :)

02-26-2008, 10:52 PM
I think I've mistaken the stuff you are using with another product but Brian has brought up a very good point. Hardie backer can suck a lot of moisture out of the mortar. The cultured stone itself can suck a lot of moisture out of the mortar too. Did you dampen them before installing?

Did you also back butter the stones to ensure full coverage or did you just push the stones into the mortar bed?

02-26-2008, 11:10 PM
Mortars are differentiated primarily by their strength: M is the highest strength, S is next, and N is a moderate strength mortar. (O and K are lower strengths yet, which is important in repair work so as not to create a mortar that is stronger than the wall/units where it is being placed.)

there are three common types of mortar specified for new construction today and are N, S, and M. These were assigned by taking every other letter from the term “mason work.” you will notice that an “O” and a “K” also appear in that term. While these are recognized mortar types, they are typically used for non-load bearing walls and for tuckpointing or other repair work.