I am in the process of deciding between CT and JH cement board siding. Any input on which way to go and why would be appreciated. Zad

Just finished that quest myself. You will hear lots of smoke about both, but my conclusion was that they are both good products.

Certainteed is cheaper right now as they are trying to win market share from Hardie.

How thick is the ct siding? I don't know much about it. I've heard hardie is very thick and if you're wanting to add 2 or more inches of foamboards you're going to have one heck of a thick wall.

Both of the fiber cement siding brands are 5/16" thick.

Will that be a problem if someone wanted to add say 4" of foamboard insulation underneath it? Would it create a wall that's too thick for a normal window?

I dont know which brand has more market share in my area, but I've seen more Certainteed failures and actually replaced a Certainteed failed southern exposure on a home that was about 4 years old and was a predrilled installation. I've seen Hardie failures too, seems to be earlier generation product though.

Drive around and look at fiber cement houses that are a few years old or more and you'll notice alot of failures.

Drive around and look at fiber cement houses that are a few years old or more and you'll notice alot of failures.

Considering the number of installed locations out there, do you think the "failures" are a result of bad product or bad installation?

Could you describe the symptoms of the failures? Moisture problems, structural/fastening defects? Am interested in using cement board in conjunction with 1.5" exterior foamboard and a 0.5" furred out drain plane over a SIP OSB panel. However I am seeing more "probably shouldn't be done" comments as opposed to the "very doable with the right details" comments. Nothing like real world experience to set a beginner straight. This build would be in Boise ID so not alot of humidity or unusual weather events.

Posted By greentree on 01 May 2012 08:33 AM
I dont know which brand has more market share in my area, but I've seen more Certainteed failures and actually replaced a Certainteed failed southern exposure on a home that was about 4 years old and was a predrilled installation. I've seen Hardie failures too, seems to be earlier generation product though.

Drive around and look at fiber cement houses that are a few years old or more and you'll notice alot of failures.

Details count.  Tell us more!

There has been one siding failure in our neighborhood where two pieces of HardiePlank siding about 6 ft. long were peeled off of a friend's house due to very high winds. In high wind areas, the siding is supposed to be installed using face nailing rather than blind nailing, and these were blind nailed. In blind nailing, the nails go through only the top of each new course, while in face nailing the nails are put in through two courses of siding, the bottom of the new course and the top of the previous course. That has been the only HardiePlank siding failure in this relatively new housing area of about 50 houses.

The houses here are too new, and the area too dry to worry much about moisture problems.

Improper installation can't be laid at the feet of the manufacturer, eh?

When installed backventilated with a rainscreen gap I can't imagine moisture related failures would be very common either, in any climate. (This is where the Canadian building codes have it dead-right, prescribing a 10mm minimum rainscreen independent of siding type.)

Face nailing vs blind nailing isn't the only decision one needs to make with fiber cement siding. Very few subcontractors who looked at my job had a viable plan for putting fiber cement over ICF. Almost none of them had any knowledge of fastener materials, shanks, head types, thread patterns, etc. To them, everything was just a nail or a screw, yet real world testing shows us that there are marked differences with all those things. Trim and transition treatments can make a difference in strength and weatherability. Technique can be important. A course of siding that might stay on if the nails were properly seated might be blown off if the nails crushed the material or were set at an angle. Even the season plays a part as you might be able to successfully nail to ICF in warm weather, while it is nearly impossible in cold.

There is too much discussion of brand merit and too little adherence to the proper application. Probably because it is easy to pan one brand or another and not so easy to go in and inspect for consistent and proper installation.

Posted By ICFHybrid on 01 May 2012 08:49 AM

Drive around and look at fiber cement houses that are a few years old or more and you'll notice alot of failures.

Considering the number of installed locations out there, do you think the "failures" are a result of bad product or bad installation?

I believe it to be both, but mainly installation failures. Installed exactly how the manufacturers want it to be done is a very time consuming and expensive proposition with anything but basic installs as anyone who works with it knows. Certainteed failure was both a material and prefinished surface failure and was time and material was paid for by the original supplier (finish applicator), I'm sure Certainteed shared in the cost as well as it was a fairly expensive ordeal on a high end home. In the neighborhood of 12-15 square, only on one southern exposure. Somewhere I have all the pictures of the material failure which was, like you mainly see, cracking around blind fasteners at butt joints. That's how it was first noticed as some butt joints cracked out of plane. Upon closer inspection there was also prefinished spider cracking all over the place. The finish looked fine from a distance but up close it was bad. Upon ripping off the entire side, fastener location was verfied and documented, hence the claim was paid out including demolition and the amount allotted was actually increased from the first offer. There is a hotel near me and the siding is literally falling off, exposing....bare OSB, nice! I'm sure that's an installtion issue, but I have noticed A LOT of crappy looking fiber cement when working around job sites in different areas wherever I am. When I travel that's what I notice, I saw some last month in Florida, last weekend in the twin cities. I noticed some issues in Europe, this is not an isolated issue. Actually, while typing this I remembered another one, I did rip off and replace fiber on a restoration job. That was because of lack of a kick-out flashing and resulted in OSB turning to mush and the fiber losing its finish and cracking from excessive movement, I belive that was an old generation board, not really the boards fault, but kick-out flashings are a part of the exterior system and needed. It's really in the details. Again, there's more good installations than bad, but there's more bad then you would think and its cropping up more and more as the boom homes age. It's not an installer friendly product, which I think is the main problem of the product. So if you want it, pay for it.

I have a different impression of fiber-cement siding than what greentree has expressed. My parents had asbestos siding, which I consider similar to fiber-cement, back when asbestos was not a bad word. It replaced clapboard siding that was a pain to keep repainting. The asbestos siding was maintenace free and looked fine for 45 years until the house was replaced with a McMansion.

The fiber-cement siding in this area looks better than most of the alternatives. Modern brick also lasts well, although they made local bricks here 100 years ago, and that brick is turning to powder. The old brick was not fired properly, if I understand correctly. I have had problems with cracking in the mortar between bricks in areas where the ground settles, and spent time trying to fill in all the cracks with filler that never quite matches the original mortar. I like my fiber-cement siding!

I don't know if Hardie has run into this problem, but my neighbor has an issue with his Certainteed CF. It seems to be cupping/curling. I don't know if it's all sides, but I know the south side is doing it pretty bad. I can see it when I drive by and his house is about 300 feet from the road. He owns the local lumberyard and Certainteed is supposedly going to replace it all. He got the pre-finished siding. Maybe it's an issue with the paint or the painting process.

I've done Hardie on my house and my detached garage. The garage I built in 2006 and the house I'm siding right now. The only thing I can mention, and I know most contractors don't do it, so it's worth watching for. Back the but joints with a small cut sheet of aluminum. Don't rely on caulk. As a matter of fact, I wouldn't even bother caulking, because it won't last long. The CF siding expanded and contracted more than I expected. Also, the CF siding lays tight against the wall. If there are any imperfections (bowed stud, crooked wall, ect) it will show. I find that if the walls are less than 15' or so in length, it's not much of an issue, but if you have a 50' long flat wall, you will see all imperfections. Vinyl siding is better about floating over these problems. So, if you have any of these issues, be prepared to shim between the siding and the wall if needed.

Also, keep a quart of of paint handy and a small felt trim brush and coat every cut edge. I know this is an other "skipped" step, but I think it's important.

I put JH siding on the addition on my house. It was originally aluminum siding. Working on the industry I saw too many color match issues with Certainteed use them. I also do not like that they will sell their name for other companies to label their products with the Certainteed name. MI Windows does this then charges a premium for the Certainteed named product. They are the exact same product other then the sash lock.

Where I see failure with fiber cement is when it is installed too close to moisture. I used Versatex starter board, stealth corners and stealth trim boards rather then fiber cement. I then painted them to match the siding. It has been 3 years now and everything looks great.

All of this is from around 3 years ago. Things may have changed...

I'll bet it's the next fiberboard fiasco. 3 years old it should look great, it should look great in 30.

I'll bet it's the next fiberboard fiasco.

Is that based on anything more substantial than pure conjecture? There are millions of Hardie installations out there.

Pure conjecture.