use concreteboard / hardipanel to enhance LF TL performance?

First off, greetings and heart-felt felicitations to ALL of the originators, moderators and participants of this marvelous resource. This is truly a fine example of what the internet could/should be. I am a newbie who has been poking around in this forum for nearly a year and am still not yet ready to present my first plan to your collective perusal for comment, but have been encountering recurring issues relating to my involvement in other construction projects and would like to ask a question that i have not (yet) seen addressed elsewhere in the forum with any specificity.... From all that I have read thus far, it seems that gypsum board (doubled using GG on both sides of a double wall, for example) can be very effective in cutting down on sound transmission ABOVE 125Hz, but that it basically sux for low frequencies. All I deal with is reggae and there is ALWAYS a really heavy bass component involved. Has anyone published studies involving use of concrete-based tile backer board and/or hardi-panel in comparison to the use of plain gypsum? Some of those backer boards contain a styrofoam component and seem somewhat porous, but the hardi panel stuff is more like laminated layers of paperboard somehow impregnated with concrete. I did note where someone agreed that it might be useful as an exterior home siding in his NYC application, but I am more interested in it's possibilities for isolating a voice booth or a mixing/control room.... thanx in advance for your consideration, pablo p.s. -- if i can get my "plate" cleared off sometime in the next six months, I'll be planning my own space in 2008!

Hardie Panels are TERRIBLE!! As far as the panels themselves go! I have a stack of Hardipanel Stucco in my driveway thats going back. You need special everything to hang them correctly (Z channels, trims, started strips down to the special nails) and no one (Home Depot, Lowes, etc) carries, or can get the needed accessories unless you buy bulk. :evil: They are also heavy and horrible to even try to work with. :evil: As far as for sound isolation, I have no idea because I didnt get that far, because after trying to hang the first sheet and finding out all the extras needed, and how easily they crack and break, I called Home Depot and told them to get this crap out of my driveway. :oops: :evil: Again, Home Depot sell's the junk, but they DO NOT nor can they get the needed extras to install it. :evil: (only found one place online that sells the needed extras to install it, and then you have to buy bulk to get it) If you want $1000.00 worth of the 4X10 stucco panels, let me know because Home Depot said after mine is returned, they are going to have to give it away. :shock: AJ

Pablo, the answer is "no" a study has never been done...... BUt - to respond to another of your comments - no one (who knows anything) ever said that drywall was only effective down to 125 Hz - because that just isn't true............. What it takes is mass - and adding drywall adds mass........ you can try the other products if you wish - just let us know how they work out........... Rod

Hardie Panels are a trusted product to use in exterior siding applications in our current building industry, are not crap, are difficult to hand nail. It is, after all, a concrete product. Brien

...and the depth of the gap between the leaves is just as important as the amount of mass the leaves have, especially for low end transmission loss (TL). In other words, two massive leaves with a small air gap will perform poorly in TL, while two leaves of the same mass with a large gap will perform much better in TL. --Keith :mrgreen:

xSpace wrote:

Hardie Panels are a trusted product to use in exterior siding applications in our current building industry, are not crap, are difficult to hand nail. It is, after all, a concrete product.

Very true. I would not hesitate to recommend it as an outer skin on a standalone building -- even a studio, although in the case of the studio where indoor-outdoor TL was critical, I would probably advocate two layers of sheathing between it and the studs. Too bad I didn't have a large back yard on my property, or else I'd have probably done exactly that. --Keith :mrgreen:

Hardie Panels are a trusted product to use in exterior siding applications in our current building industry, are not crap, are difficult to hand nail. It is, after all, a concrete product.

Well, let me change my stance on them then. I think they would be GREAT for use for like exterior covering (siding) for like a foundation area for a walkout basement or somewhere where the attention to detail maybe isnt as important,,,,,,but,,,,beyond that, forget it. When I went back into my Home Depot store, in front of me they took their Hardie Panel Sales Binder from the Pro Desk and said, "This is what we think if the Hardie Panel Siding" and threw it in the trash can! :shock: Obviously they must have gotten a bunch of complaints. But again, they said their store and the one about 45 minutes away will no longer sell the stuff, and THEY referred to it as crap as well. For Studios,,,I have to agree with the comments about the fact that they have gaps between them when installed (which I believe they make clear that you do have to have according to the install instructions) Then say hello to ongoing maintainence with the caulking etc. And dont forget the special Z channel they require you use to keep warranty on the stuff. Maybe we/I am getting off the initial question as to would they be good for Studio application,,,and my opinion (based on the recent bad experience with the stuff I just had) is no!!,,,dont bother with it.

studio911 wrote:

Well, let me change my stance on them then. I think they would be GREAT for use for like exterior covering (siding) for like a foundation area for a walkout basement or somewhere where the attention to detail maybe isnt as important,,,,,,but,,,,beyond that, forget it.

Actually - it's used quite extensively in medium rise buildings (3 to 6 stories) for siding - and the fact that the people who work at home despot think it's crap doesn't mean much to me........ home despot is not selling the same products that you buy from the real suppliers....... for example - take any one of their plumbing products and check it side by side with something from a plumbing supply house - and you will see an immediate difference in quality - it is inconceivable to me that a product like Hardie Planks is carried bvy a company that won't carry all of the parts and pieces that Hardie makes to install their product - and then they'll bad mouth the product as if the problem is the manufacturers. James Hardie Co. has been in business for over 100 years - they must be doing something right........... Rod