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Hardiplank siding installation

BSzydlo's picture

When installing hardiplank siding over 7/16 osb do the butt joints have to meet over a stud?  I know this is probably a stupid question but while reading the installation information it is pretty vague.  Any advice would be appreciated.



they do not have to land on (post #206998, reply #1 of 20)

they do not have to land on the studs.

look it up..... (post #206998, reply #2 of 20)

You need to get the factory hardie install info.

Seems to me they once allowed breaking between studs but changed their recomends. But then that's just how I remember it.

Also there are the off stud joiners to consider which are end clip hardware.


As of Aug 2011, James Hardie (post #206998, reply #4 of 20)

As of Aug 2011, James Hardie states that hardiplank can be installed directly to 7/16" osb for HZ5 and HZ10. They do recommend nailing into studs.  The butt joiners would still be a good idea in my opinion.

I just finished installing (post #206998, reply #3 of 20)

I just finished installing 2000 sticks of fiber cement by myself.

Read up quite a bit first and all the mfg install manuals said for joints to be over studs and to use siding nails or 1-1/2 or longer roofing nails.   You did not say what type of nails you are using - siding or roofing?

Of course, I ignored all that advise, and installed at random nailings, generally 12 in to 20 in depending on how tired or how high the siding was.  However, was NOT nailing to osb, was nailing to 23/32" 13 ply baltic birch sheating with 1-1/4" nails. 

Did do a test first - on the birch, the fiber cement broke before the nails pulled out of the siding, on osb the 1-1/4 nails pulled out of the sheating so would go with over the studs or longer ring shank nails on osb.. 

Suggest you do your own test with a sample, if the siding breaks before the nail pulls, dont bother trying to hit the studs.

Better to make it a (post #206998, reply #5 of 20)

Better to make it a rainscreen:  Apply 1x3 battens over the wrb by screwing into the studs. Then nail the siding to the battens.

Winning answer! (post #206998, reply #6 of 20)

<DING DING> Winning answer!

YAY!  I love WYSISYG editing!  And Spellcheck!


Butts (post #206998, reply #7 of 20)

One alternative to locating the butt joints on a stud is to let them land anywhere and use 1-1/4" screws to secure to the sheathing.  Nailing within 3/4" of the end of the panels often results in broken corners.  With easy-to-install star-drive screws, you can put them 1-1/2"-2" away from the end of the panels, no broken corners.

Don't forget the flashing behind the butts!!

Gary- Research and Development


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Gary (post #206998, reply #8 of 20)

Those are some large looking heads. 

And would they bore through and flush up in fibrecement?

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Heads (post #206998, reply #10 of 20)

Yes they do pull up flush to the surface of the fibercement.  With the cutting nibs under the head of the screw and the knurled shank that reduces drag, the head sets flush.  The head size is typical of any wood screw in similiar length.  We have also used this method at the house corners, with wide trim there is not any backing to nail to, the screw-sheathing method works!

Dan-  When nailing the butts to a stud, the nail needs to be within 3/4" of the end, or it's a miss....  With a screw to the sheathing, you are able to move back a little and still hit the target (sheathing).  A nail into sheathing only is useless in most cases.

By not hitting the studs with the butts, alot of cutting is eliminated, which is a GREAT thing.

Gary- Research and Development


Why would using screws let (post #206998, reply #9 of 20)

Why would using screws let you secure the sheating farther from the ends than using nails??

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

I'll bet I can drive four (post #206998, reply #11 of 20)

I'll bet I can drive four nails using my siding gun in the time it takes to drive one of these screws. And I'll bet I can roll paint onto a couple of square feet of siding fastened with flush sitting nails in the time it takes to spackle the heads on the screws. So for time efficiency a nail gun will win out every day. Not to say that screws don't have their place. Like for fastening the battens on a rainscreen installation.

Nails (post #206998, reply #12 of 20)


I was not suggesting exposing the screw or the nail, but using them under the normal lap situation.  I was not suggesting replacing your nail gun, except where there are no studs to hit, like in a low-sloped gable, around trim, etc.  A good screw, in these situations, is much better than a nail.  Speed is not everything.

Gary- Research and Development


nails v screws (post #206998, reply #15 of 20)

Gary, your comments are spot on! I've done many fcboard siding jobs. I either use screws exclusively or a combination of air-driven, factory-approved siding nails and screws. Roofing nails do NOT perform the same as factory recommended nails! I suspect few installers bother to see what happens on the back side of the board when an improper nail is used. They fail to see that shattering of the board's brittle back side significantly weakens the holding power of the fastener. Yes, screws are slower to install than power driven nails, but screws allow me to perfectly align the board to the substrate. This is important if one wishes to achieve perfectly mated butt joints. There are rare occasions when I need to face-screw the exposed bottom edge of a butt joint. In these cases I use GRX finish screws. I predrill, lightly countersink each screw, and fill the hole with...shudder...tile grout! You heard me right, sanded tile grout! Dried tile grout is about as close as you can get to fiber cement board.  I sand and prime. When I apply Sherw. Williams Duration brand paint, the joint looks perfect. I challenge readers to find butt joints in the photo attached below! BTW, I never use pre finished siding boards. I prefer to place my butt joints between studs. Screws used between studs should be seen not as primary, but rather as secondary fastening  points. Their purpose is "cosmetic" rather than load-bearing.

Let's be clear: installing fiber cement board siding is time-consuming and skilled work. It is co$tly. It's the exact opposite of installing vinyl siding (shudder!).  Nothing less should be expected from a siding meant to last 50 yrs or more.

Mel Fros

Joints_do_not_show.jpg26.64 KB

Hey Mel (post #206998, reply #16 of 20)

No kidding, a photo that small way.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Reply to Calvin (post #206998, reply #17 of 20)

Ignore the photo and let's talk about the merits of what I've written! :) 

The fact is that there sometimes are gaps between overlapping boards, or butt joints don't meet in the same plane. Caulk is NOT the answer! I solve this problem by applying countersunk, GRK brand finish screws 1.5" above the bottom edge of the offending board (so that the screw just misses the top edge of the previous board). Then I fill the screw head with tile grout, sand it, prime it, and paint it with SW Duration house paint. Duration is not the easiest house paint to work with, because it has an additive in it that increases the "grab" and therefore the "duration" of the paint job.  I could write a  whole lot more about the finer points of installing fiber cement board siding. If there is interest here, I just may to that...and attach illustrations. Hmmm?

Mel Fros

If you're installing FC with (post #206998, reply #18 of 20)

If you're installing FC with screws you're either overcharging the customer or are willing to work for less. There is no advantage

at all to using screws over ring shank FC nails and lots of disavantages.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

Reply (post #206998, reply #13 of 20)

Are you doing the installation yourself? That is is quite a hard job to do. You can ask an installation expert about that.


Siding the Woodlands

Hopefully, it is done by now. (post #206998, reply #14 of 20)

Hopefully, it is done by now.

i never see anybody use bevel (post #206998, reply #19 of 20)

i never see anybody use bevel joints, only square butt joints, how come?

yhanks, douglas

one reason.. (post #206998, reply #20 of 20)

FC is crumbly stuff,  way too weak to put a 45 bevel on.