Expert: Bruce E. Johnson - 4/19/2011

Question
QUESTION: Hi,

What is the best practice when installing Hardiplank, to install window and door trim first and then butt up to it, or lay the trim on top of the Hardi?

I'm mostly concerned about looks and weather-proofing.

Thanks very much.

ANSWER: Hi mike, hardi makes it's trim thicker so that it can be installed first and the hardi plank butting into it.  I like to flash around all my openings with peel and stick rubber, install the hardi trim and then the siding, followed by a good urethane caulking..remember when installing any kind of wall wrap and flashing to use the "roofing" principle..in other words your bottom layers are lapped by the upper layers similar to how felt paper is installed on a roof.  Follow that simple rule and you should be fine..I hope this information helps, please feel free to write again regarding this or other matters, sincerely Bruce E Johnson ..bejohnsonconsulting .com

---------- FOLLOW-UP ----------

QUESTION: Thanks very much for such a clear, prompt answer.

One more, if you don't mind? (Okay...to be honest, it's a four-parter.)

Where should the bottom edge of starter strip land relative to the slab/sole plate interface (or bottom edge of the OSB sheeting)?

Do most guys just rip a 1.25" length from one of the hardiplanks to use or does Hardi provide precut ones?

Can one of those nibblers cut a straight enough edge that I don't have to rip it on my tablesaw? (I've heard about the dust!)

Does the starter strip need some separations every now and then for weeping?

Thanks very, very much!

Answer
Hi again Mike, Hardi has specific requirements for installation.  The bottom of the Hardi needs to be 6" above finished grade of the surrounding yard or 4" above concrete.  Because of this most Hardi installations include a pressure treated base shoe to be installed and then the hardi butting into the top of that after a piece of Z flashing.  As far as the starter ripper, I use pressure treated 1/2" lathe strips 1 1/2" wide.  I usually hold this material up an inch from the bottom of the hardi. The rough lathe has enough irregularities and it comes in 4' pieces so that water will find a way to weep out. I hope this information helps, please feel free to write again regarding this or other matters, sincerely Bruce E Johnson ..bejohnsonconsulting .com