Which one say you, texags? Virtually the same price in this case....the advantage to Smartside I see is its lighter/easier to work with (which I don't care about because I am not installing it) and disadvantage is its an LP product which fell on their face with their last "engineered masonite" product. I am redoing my whole house with the respective trim and need opinions from those in the know on smartside. Thanks and Gig 'Em.

Since you're not installing it, it's a flip of the coin to me. I installed Hardi on part of house and will never do it again -- nasty! I replaced part of the siding on my workshop with Smart and it was soooooo easy compared to Hardy. Have not had any problems with either since, hence, my attitude that it's a flip of the coin if price is same.

I have used both, and Smartside is much easier to install but I think Hardi will have more longevity. I have even had a piece of smartside sitting in the dirt next to a piece of hardi for about a year and the hardi is holding up better. Also, the edges of the smartside don't look as good when they are finished(painted). If you are not doing the work I would go with Hardi.

Hardi. Even if you *are* doing the work. And make sure the installers are using the right saw blade for the Hardi.

There was a guy running around here a few months ago that was a big fan of the SmartSide. I put the two together and examine them and basically found that the Hardi is a cementboard... where the SmartSide is basically cement dust, sawdust, and some other binder materials. Which one do you think is going to resist rot better? The completely inorganic one, or the one with a bunch of organics thrown in?

I have had great success with Hardi and using Big Stretch caulk as sort of a 'glue' between butt ends of pieces placed flush to one another. The Big Stretch doesn't crack in the sun like I've seen all the other types we used on this one project do, and it's paintable unlike silicone.

Smartside comes in 16-ft lengths, whereas Hardi only comes in 12-ft lengths. If I were doing it myself, I would definitely use the Smartside. It is much lighter and you can cut it just like wood without having to worry about the silica dust.

Also, what the previous poster said about the Smartside isn't exactly true. There isn't any cement in the Smartside. From the backside of the Smartside it looks identical to a sheet of OSB. From their website:

quote:

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The process begins with either wood strands or wood fiber. A zinc borate compound is applied throughout the substrate to help protect against fungal decay and termites. Superior exterior-grade resins are used to create extremely strong bonds within the product.

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The one concern I have is the previously mentioned old LP siding that failed so miserably. But, the Smartside has a 50 year warranty which is much longer than the Hardi siding. Also, any company that bounces back from such a failure would be extremely careful to not make the same mistakes that they did previously.

10-4.....as I said, I understand the fundamental differences between the products, and I have read all of the specs. As you guys know, sometimes the product data does not exactly match the guarantees of the product. The other thing I am concerned with is my exterior walls are framed in 2x4 @ 16", which in my mind is not much to bear the weight of OSB and hardieplank (its so dang heavy). The weight of the smartside was another thing that I saw as an advantage. I appreciate everyones help. Exterior siding is always a big investment and I am always wary of new products....

Don't worry about the studs holding up the osb. That is a non issue. In fact, the osb-stud assembly will be stronger than what you have now. The main reason houses typically use 2x6 studs now is for more insulation, not weight bearing properties. Concerning the siding, the argument between these two products is pretty futile. The main reason any of these siding products fail is because they are installed incorrectly. Smartside is not like the masonite products of old. It is a much better product and with the correct flashing, paint and MAINTENANCE it will probably last a very long time. I would spend more time reading the specs and installation instructions for each than worrying about which is better, because if you install either of them wrong and they fail, then the warranty doesn't mean squat. As an alternate you could look into Miratec. They claim they are better than smartside.

BTW, I second that Big Stretch is a good sealant. Also OSI Quad, except that it is not water based so it is harder to clean up.

Thanks builder....I had not thought about the OSB adding structural integrity....I was thinking it was just adding weight. I printed off the install instructions for each last night and will review them this evening to see which is more "user friendly" to maintain warranty. Thanks again to all.

Builder93, can I get your advice?
Right now my home has 1/2" Iso board (foil faced both sides, basically a vapor barrier as it has a very low perm rating) over the 2x4's. The siding is directly over that. Hardie or Smartside do not spec backer materials so they have no preference per warranty, but would you, bearing cost and quality in mind:
a) Leave iso board in place, and wrap it in hardie wrap or tyvek to maintain the weather barrier (the iso board/barrier will be damaged during demo almost certainly, hence the reason for the wrap). This would also alleviate the cost of osb sheathing.
b) Remove iso board in its entirity and replace with 7/16" osb, wrapped in hardie wrap (or tyvek).
c) Leave the iso board in place, and cover with 7/16" OSB which is then covered with the hardie wrap (this is what my installer is recommending cause he wants the added r value which is minimal, I am concerned this will create a vapor trap given the low permeability of foil faced iso board and osb on top of that).