hardibacker vs. fibrerock (talk amongst yourselves)
After extensive archaeological research on the "No More Greenboard" thread, I decided this was a subtlely different question deserving of its own caterwauling.
I have some bathroom wall skimming and other more eclectic applications where I would normally use 1/4" hardibacker. We've paintted it with latex milk for skimcoating with Diamond where used in the plaster wall context and of course used as moisture resistant substrate for flooring.
The Fiberrock is about 25% cheaper (or put another way the hardibacker is about 33% more). $8 a sheet for FR and $11 for HB.
Aside from not having some grid lines on one side, is anyone familiar with significantly different material content or function between the two products?
The one use is as cited above for plaster skimmed walls in bathrooms (but not in shower enclosures, although it seems either would serve in these areas as well if other waterproofing/seam treaments are observed)..
The other thing I want to use it for although I'd been planning to use 1/2" thick material (don't know if FR is available at 1/2" or if it would be equivalently cheaper that HB 1/2") is as underlyament over foam with passages for warm floor, where one side of the underlyament would be in contact with the top of the pipe and with aluminum sheeting surrounding the back of the pipe. (I'm also interested in 4x8 availability, but where I have found HB available in 4x8, they are looking at a 50% premium over the 3x5s so I may just have to forego that idea although I don't know if you can get FR in 4x8).
Both FR and HB seem as if they would be reasonably good at heat transfer and the finish flooring would either be wood glued and mechnaically secured to nailing sheet under the foam, or it might be tile or carpet. Obviously the floor finishes all have their own issues in terms of radiant heat, but I'm trying to get the best start that I can by chosing an underlayment that has a bit of mass and the least possible "R" value of its own.
Re: hardibacker vs. fibrerock (talk amongst yourselves)
I prefer the densheild myself,, and no it is not as easy to finish over ,, John if your plastering over it,, would you run a tight skim first with the diamond? That is normally the way I work it with the DW compound,