Fiber Cement Board installation

[davinci]

you guys like using this product? i always worry that on an older house it will appear wavey.
you guys ever use insulation board under it? or just tyvek?

[enforcer]

normally you won't use insulation board with fiber cement only house wrap. davinci,you seem like a nice guy and also seem to ask alot of questions(thats a good thing) and i respect that. but please,make sure your installer knows what he is doing with fiber cement or else you can find yourself with a world of problems.

[WNYcarpenter]

I've run miles of fiber cement...not to say our method is best. I liken fiber cement to drywall. Every framing/sheathing discrepency is magnified.

On new construction we apply the siding directly to the plywood/housewrap. On some remodels without enough stud cavity depth to get the required R value we have used insulation board. but in those instances the siding was board and batten.

It is my honest opinion, the only to avert waviness is to fir the walls (strap), or carry around a bucket of shims and eyeball every other course.

Waviness is what it is no matter what type of siding you're using. My biggest problem with fiber cement (clapboards) is that it isn't beveled!!!! I can stand a little waviness on a long wall, but the gaps under the siding because it doesn't lay flat is terrible. I'm not sold on the product and we've been installing it regularly for 8 years.

If you're unfamiliar with the product just have a little patience and learn a few of the tricks, it takes a little getting used to.

[Fuzzycram]

I haven't ran across a time where I needed insulation board. What I HAVE ran across is replacing siding on old houses where the walls weren't even sheathed and just had insulation and roofing felt on them. Here in florida when you find an exterior wall that is not sheathed, you gotta put plywood on it. Home owners are always pretty upset... ALWAYS use some sort of vapor barrier underneath. Tyvek is the SOP.

[clapboard]

We have gone up to 1-1/2" rigid foam under the siding nailing into the studs. Tarpaper is the best underlay. Tyvek is a rip-off scheme that does not work for allowing moisture out of the wall.