hardiplank siding does indeed come in 12" pieces. And yes you do need to seam the sidind on a stud. They do market an aluminum off stud flashing that allows you to splice off the stud, although I have never used it. http://www.prosidingaccessories.com/cement-osj.html
A good siding practice is to use junction flashing behind butt joints in the field, you can make your own or order them from prosidingaccessories.
Here is a link to the best installation practices for Hardiplank siding... It is broken down into regions. I also would encourage you to read the manufacturers installation instructions- it'll keep you out of trouble.
always strap over the studs and break the joints ther, however if you run into an odd length wall and you need to break a course where their isnt a stud you can just scab a 12" piece of straping on the wall
generally just use tyvek "dollar bills" simply cut a 8" length of the roll and cut squares that go behind the joint and lap just over the last course
Hardie recommends a 1/8" gap from siding to trim, but no gap between butt joints. I worked for a company though that we took a 6d hand drive sider and gapped between butt joints though. As to caulking Hardie does not recommend the use of caulk on field joints. Because of this I use joint flashing behind the field joints, pin the corners of the abutting pieces (no shear, just aesthetics, it keeps the siding corners down and lined up) and caulk it with a 50 year elastomeric caulk.
I do not even try to splice on the stud to brittle to nail that close to end
i splice anywhere I put a piece of tin behind about 6" wide
and high enough to go under above lap
I then caulk behind and between pieces
then I face nail joint thru tin leaving nail away from end a little
between the nail through tin and caulk behind stays together nice
I have not seen any blind nailed joints stay together very well
hope this makes sense good luck
It installs basically the same as any siding, except that it's a pain to carry and it breaks easy. It should splice over a stud as with any siding, but if it doesn't it's not that big of a deal. If your splice misses, you can go inside and clinch the nails if you're worried.
Contractor Talk - Professional Construction and Remodeling Forum
A forum community dedicated to professional construction and remodeling contractors. Come join the discussion about the industry, trades, safety, projects, finishing, tools, machinery, styles, scales, reviews, accessories, classifieds, and more!