Some friends asked me to look at their Hardi Plank. On the west side of the house, exposed to the afternoon sun, the caulking is seperated and the planks are loose. Looks to me like inadequates nailing and lousy caulking choices(looks suspiciously like Acrylic latex) made this problem. Anybody have experience with hardi moving that much with the heat?
Dustin
Replies
I haven't seen much expansion.
Yet one more case that makes me glad I used tin joints.
Tin Joint?
Dan what is a tin joint?
Like a tin corner only not at the corner. Unfortunately (and rather oddly) no longer available except maybe by special order, since they would be a natural for fiber-cement siding -- cut installation time and maintenance.
metal joiner source..
pro siding accessories. com sells off stud joiners and joint covers in a variety of configurations,or at least did last year.
I used the osj's on a fc siding job, it was a love/hate relationship for my taste.
Not to put words in Dan's mouth, but perhaps he means an off-stud joiner? (Simplicity Tools: http://www.simplicitytool.com/osj.html). As for the original poster's problem, it sounds like the builder didn't follow the Hardie installation guides; butt joints are to be fitted together snugly, no caulk; preferably, butt joints should be factory ends, not field cuts. Caulk is used only where siding meets trim; all field cuts to be treated with touch-up paint.
On another note, has anyone tried using masonry/concrete/cement sealer (Sikagard clear sealer, etc.) on Hardie products for field cuts? I guess it'd be double work, since you'd still want to use touch-up paint for the color, but I wonder if cement sealer would better help prevent moisture infiltration, delamination, etc.
Not to put words in Dan's mouth, but perhaps he means an off-stud joiner? (Simplicity Tools: http://www.simplicitytool.com/osj.html).
Nope, closer to this, but still not exactly it:
http://www.prosidingaccessories.com/hardboard-140.html
They have an H cross-section, bent out of a single piece of aluminum, and the ends of the siding slide into the notches. No caulk necessary, no need for flashing behind the joint, plenty of room for expansion/contraction.
Hardi will move with heat and cold. in fact if you read the installation instructions for hardi-siding it states not to caulk field joints and to leave a marginal space between each for expansion and contraction. i have had many an argument with real estate agents over the "unsightly gaps".
when installing hardi the manufactures ask that you either drape an approved weather paper behind the joint or a tin shingle.
the same is true with wood lap siding. it depends on the installation. i was taught to skarf joint butt joints.
cheers
Jon
>>>i was taught to skarf
>>>i was taught to skarf joint butt joints.
With wood though, right? Don't know how you'd scarf Hardi if you where using shears.
yes to clarify skarf on wood lap siding.
Hardi instructions say to not caulk field joints and install planks in moderate contact. No gap is mentioned.
http://www.jameshardie.com/pdf/install/hardieplank-hz5.pdf
good pic of joint flashing
http://www.homeconstructionimprovement.com/hardiplank-lap-siding-butt-joint-flashing/