The boards are probably alright, but the siding company is most likely correct. They were installed wrong. If the siding is secure, despite the cracks, I'd leave it. If it looks like the corner are going to fall off, they can be removed and replaced like any other clap (paying attention to redrive the nails right).

I was thinking the same thing about letting it go, however, it seems that these cracks and splits are shrinking too as they pull away from the nail. I guess our main concern is will the cracking and spliting continue to show up? I think we are just not totally convinced it is a "nailing" problem since there seems to be this shrinking too. Thanks for the replies!

Fiber cement does not shrink or swell.

Sounds like an installation problem.

We have Certainteed fiber cement siding. We noticed several small cracks in our siding (probably about 8), within about 20 months of our build. Unfortunately we did not report them immediatlely and Certainteed would only replace the boards. So we have the boards (enough to reside the whole section) but have to pay for the labor on our own--which will be the most expensive part. It is complex enough that we will probably caulk and paint and let it go.

The rep that came to our home said that it is not uncommon to see cracks like ours in our region (midwest), mostly on new construction due to settling.

If we had reported the cracks in the first two years the warranty would have covered the labor and the materials (so she says--she probably would have used a different excuse if this one had not worked).

BTW, the company had a person on site with the installation of our siding since it was our contractors first job to make sure he was doing it properly. It was installed by the book.

Is this what your cracks look like?

Here is a link that might be useful:

That's interesting. Based on my DIY knowledge a vertical crack like that would signify stress from the house moving. I don't think IMO that fiber/cement has much tolerance for movement. That word CEMENT means something.

Hmmm srercrcr, interesting point--it does remind me of a crack that appeared in the concrete of our pool deck within a few months of the completion of our pool.

Our house sits on a basement and we have tall ceilings in our basement.

I wonder if this product fares better on a house built on a slab.

I guess I'm lucky that it only happened on one part of my house. It is in the back of my house, where the walk out basement is.

I hope people are aware that if you report it in the first two years after installation, the labor and material should be covered under warranty. But, do not procrastinate, like we did.

red lover,

Thanks so much for your response; our cracks are more on the corners but we have some like yours only more of a horizontal crack. I can sort of understand why they think it is an install problem because most of the cracks are on the corners, hence, must be a nailing problem. However, all these nail holes were pre-drilled and as you can see(hopefully) the nails are NOT below the panel surface as they say nor are they at an angle what they call 'directional nailing'. Builder is not happy and is trying to get a Certainteed rep out here to look.
I will try and post a pic.

Here is a link that might be useful: crack in siding

found this thread on another site and hope it's ok to link it.

Thought you might find it interesting. I did.

Here is a link that might be useful: info on siding installation and problems

that corner crack is careless installers. they were not careful and drove the nail at an angle. cement siding is very fragile in the corners and must not be stressed. you can see the nail is offset from the hole.

That was an interesting article....I just don't know what to think. I mean, why would our builder, with all his experience with the product, same crew, only boards on some sides of the house, no problems on ANY other build, all of a sudden 'screw up' our house? I went outside and took another pic of a different kind of crack. The horizontal crack is up quite a ways up on the house so I really can't get a shot of it, but it is a 'hair-line' crack running through the middle of the board.

Here is a link that might be useful: another crack

the last picture looks like some kind of movement stress crack. you can see the gap in the siding is not uniform but i cant tell if it was cut crooked or if it has somehow moved.

It's an installation error.

Twotogo,

I noticed another installation error in the picture of the "stress" crack to the left of your window. There is no horizontal Z flashing installed above the window trim and the siding is caulked directly to the trim. If you refer to the installation instructions from any fiber cement siding manufacturer, they instruct that horizontal flashing must be installed in these areas and that the installer leave an "uncaulked" 1/4" gap where the siding meets the flashing. The flashing is to prevent the possibility of water infiltration and the gap is meant to act as an escape for any water or moisture that might get behind the siding. If the gap is caulked (with or without flashing), moisture can get trapped in these areas and cause problems down the road. The fact that I didn't see any flashing above the window indicates you will most certainly have leakage issues at some point. Short of pulling the siding above all windows and properly installing horizontal Z flashing, the only thing you can do is very closely and frequently monitor those caulked joints to minimize water infiltration. From everything I've read and seen on your siding, I have to agree that it is an installation issue. Hopefully you have Tyvek installed behind the siding to prevent rotting to your wall sheathing should you experience water infiltration.

Best of luck to you

We too had a new home built and wanted fiber cement siding. It was installed with a rep from the manufacturer on site to show how. We had cracks the first year and a half everywhere, in corners, near nails, right down the center, and wherever it was cut to fot around things sticking out of the house. Now year 4 and one replacement later, THEY'RE BACK. Manufac. sends out the same form letter saying it was installed wrong. Well their rep helped with installation. they are offering only 3 sides of material and we need to install. this has been ongoing and I am frustrated. My advice, fight hard for your money back and DO NOT GET FIBER CEMENT SIDING FROM CERTAINTEED!

My hardie board plank siding was installed in 2001 and now 7 of the boards are vertical cracking on the south side of the house. lI contacted Hardie and they offered to replace 7 boards which doesn't help. contact johnr9q@yahoo.com

"lI contacted Hardie and they offered to replace 7 boards which doesn't help."

17 years later, they offer to replace the boards, and it doesn't help? What did you expect them to offer you?