How to attach hardibacker to a rebar skeleton

[Tscarborough]

Re: How to attach hardibacker to a rebar skeleton

Given that actual design, this is how I would build it:

I would form and place the first layer up to the floor of tier one of vermicu-crete. I would then build the outer walls of the first tier out of cheap brick (called utility brick or commons). I would then form and place the second layer to the floor of the second tier out of vermicu-crete, with the outer walls of cheap brick. etc. I would then stucco (SBC) the entire thing, making sure to slope each tier to one low spot and weep it at that point. I would also cove all inside corners, and probably apply a coat of Thoroseal to the inside of the planters themself.

Fast and quick, and cheap and light to boot.

[kebwi]

Re: How to attach hardibacker to a rebar skeleton

Interesting. You are echoing many of my ideas but which I lacked full confidence in. I had already hit on the idea of forming each vermicrete pour with 2"x8"x16" blocks. And I was going to weep-drain each tier of course. Another idea I had was that the third tier could be done differently from the lower two tiers. The third tier could be walled up in the same cheap concrete block you mentioned, the 2" cheapo stuff I was thinking about. But then instead of pouring it with vermicrete, I could just roof it with hardibacker or durock and fill in under with with vermiculite.

There may not be much utility in doing the third third differently however, so I may not bother with that.

One thing that had scared me off the cement brick form walls was unassuredness as to how I would cut them when and where necessary. They are only 2" thick thankfully (actually 1 5/8" if I recall). Could I cut them with the HF tile/brick saw? If so, should I get a different blade from the one I used for the bricks? Should I get one of those segmented blades to cut these things?

Thanks.

[Tscarborough]

Re: How to attach hardibacker to a rebar skeleton

Yes they cut with the same blade. They will, in fact, "sharpen" the blade by removing some matrix from the edge.

[kebwi]

Re: How to attach hardibacker to a rebar skeleton

I forgot to mention, I had had another concern about the concrete block wall when I was first thinking about it. I was worried that after the vermicrete cures and I "let everything go", that the blocks forming the wall would fall away, that they wouldn't be firmly bonded to the vermicrete. Is that not likely? Will they basically glue to the vermicrete solidly?

I was thinking about various ways of fixing this, but they all seemed difficult. One idea I had was to drive a rather long tapcon into the block faces with a large washer such that when the vermicrete was pour behind the wall it would lock against the washer and hold the block to the vermicrete.

Or tie plates between adjacent blocks to hold them together...lots of tapconing, sigh.

Is none of this necessary? Will the poured vermicrete hold them solidly? If not the only thing that will hold them in place is the surface bonding cement (stucco).

...although I still might wrap the whole thing in chicken-wire before stuccoing too, so I guess that's another possibility.

What do you think?