On Sat, 22 Apr 2017 10:51:52 -0700 (PDT), "
wrote:

On Saturday, April 22, 2017 at 8:28:37 AM UTC-5, dpb wrote:
On 04/21/2017 11:32 PM, Leon wrote:
...

I have used both types. Time is money.... but Hardie requires a special
type of primer that will stick to this type material. Not that this is a
problem but if it is not right, the paint may fail. Preprimed, you know
it is the correct coating.

What (I think?) I've learned is also that those with prepainted in all
the class-action lawsuits against Hardie have had early failures in
multiple ways including the required/recommended color-matching caulks
turn color that don't match, finish coatings are thin and washout
quickly and all kinds of tales, even when (purportedly) installed per
spec's. I'm thinking I'm staying away from cement fiber based on what
I've seen so far...

For me, a huge consideration is to deliver a warrantable product. For all that you mentioned, I stay away from the prepainted Hardie. I never put any up for exactly the reasons you state. Shingles are colored by batch, and one manufacturing run doesn't match another exactly. Wallpaper, the same. Batch runs of tile, paneling, brick, and on and on don't match one another. So how could batches of Hardie? Since it is expensive, you only order what you need, and if you need to go back for more, your prefinished pieces don't match.

Hardie flip/flopped on caulking joints on the prefinished product since their own caulk didn't match, so when the launched the product we were to caulk; several years later, no caulking on the prefinished stuff as per their instruction. So what gives? Same product, one is painted, one is not. Worse,the ambiguity of their instructions make sure they warn the potential installer to be aware of the fact that on long runs there is enough thermal movement that the joints SHOULD be caulked.

https://www.jameshardie.com/d2w/inst...-hz5-us-en.pdf

So what is the message? On houses with long runs, don't use the prefinished?

But it gets worse. Since no one reads the instructions, they don't flash EACH butt joint as required. Every one should be flashed. I am the only installer I have ever seen that does it though, even the largest "certified" installer here locally does not. So if you don't flash the butt joints and don't caulk them, you will get water behind your siding.

According to the Hardie site, the flashing can be just a piece of
house wrap. They describe how to saw off the end of a roll so you
have essentially a TP roll the right width for the joint. I've also
seen aluminum widgets for this but even on Amazon, they want over $2
each for them. Yikes!

Prefinished siding from Hardie doesn't match their own recommendation of finish thickness on the siding. Somewhere in their literature they require a minimum protective finish (latex paint) of 1.5mm. They may have changed that by now. However, a the time I measured the demo product with my micrometer the factory finish was less than half that. The Hardie rep assured me that it was fine since it was applied in perfect factory conditions to their specs and under their supervision. Bull****. Too thin is too thin. The prefinished product is soft, scuffs and damages so easily that simply movement of the material can cause scuffs, and scratches that require repair. And no paint, regardless of the accuracy of the original quality of color match will wear to the same color as a dissimilar product used by the factory.

Paint shouldn't be that bad, these days. THe problem I see is fading,
which shouldn't be a problem if just "running out". I've touched up
interior wall with paint bough several years later. It looks like
hell until it's dry than I couldn't see where I stopped. Tile
(doesn't matter what type) is a PITA because you even the size differs
by lots.

That being said, Hardie has its place for me. I have used a lot of it and had great results. As Leon said, primed is the ONLY way to go. Since it is almost never stored correctly, primer provides a little protection against water and humidity absorption. I only buy from one local lumber yard that sells a ton of the stuff as it always fresh from the factory.

As I said earlier, I have to replace six or seven squares over the
next few weeks. I'm considering the painted boards because it may be
a while before I can get it all up and you folks have me worried about
water. I'll still have to paint it to get it closer to the rest of
the house (though the other Hardie sided sides can't be seen at the
same time, at least by anyone other than the deer).

That said, I was looking at the boards at Lowes today. The aren't
primed on the back so water could easily penetrate the fiber. Will
water be a problem after it's hung, perhaps before the job is
complete? I'll probably store it in the garage and let my truck sleep
outside for a while.

The pre-primed material holds paint very well, and one of the advantages of the preprimed is that you only need to put on a couple of coats and you are done. Properly painted, it looks great for years and years. Many companies like Sherwin Williams have modified some of their formulations to accommodate cement board products.

If I didn't have an airless, I would still wouldn't use prefinished. But as I do with a lot of installs, I would prefinish myself. It is easy enough to lay out Hardie across sawhorses and roll it out. It takes no time at all to roll a couple of coats and they are are ready for use later in the day or at least by the next day. I can put a helper on a 6 inch roller with a five of paint and he is a busy boy, but a helper can now pre-finish your siding on the ground. Scuffs and touch ups will match as you are using the exact finish you applied, and your nailer/installer can do his own touch up before moving a ladder if it is more convenient.

What do you do with them after you've rolled them? THat's a lot of
boards to lay around. I did it with the cedar I used on my VT house,
so I could get the backs primed but it was a PITA.

Just thought I would put all that out there in case someone is thinking of Hardie or any other kind of cement board installation. It lasts well when put up correctly, but you must follow the instructions perfectly.

I really appreciate your help. It's awesome and at exactly the right
time for me. Thanks!