I’m fortunate to have stumbled on a great deal on prefinished 6.25″ fiber-cement siding for my cottage renovation. It was an ordering mistake (architect wanted smooth; this has the woodgrain effect) and I bought the whole lot, thinking I could use the extra pieces for trim. But the James Hardie website says it shouldn’t be used for that purpose without explaining why. If it’s the thinness of the planks, why couldn’t you layer it up to the thickness you need? My primary use for it, by the way, would be for the outside corners of this one-story home.
Thanks!
John in Pittsburgh
Replies
Probably not recommended because they want you to use hardi trim. Hardi plank is very flexible for trim though, I wouldn't try it, not saying you can't...
A bit too thin for trim, I'd think. Trim is usually more than twice the thickness of two layers of siding, so it stands a bit proud of the overlapped siding -- makes it easier to caulk the seam properly. Layering the stuff to gain the necessary thickness would be an invitation for water to wick between the laminates and give you freeze/thaw nightmares.
Mike Hennessy
Also Pittsburgh, PA
The trim we use with Hardie plank is 1" thick.
Maybe you could use the siding as trim, but IMO it would have to be backed with probably one by material that was also suitable for exterior use, in which case you wouldn't be saving anything, not to mention the extra labor involved. Square peg, round hole.
I saw Tommy and Norm do this on a TOH episode. They alternated the laps on the layers at the corners like you would with cedar shingles to make it water tight and the last layer overlapped the siding boards to cover up the ends of the rows. I was shaking my head at the time but I guess it was working and it probably is still today.
Wayne
On my current home I put up Hardiplank just before the Harditrim was available.
Having slightly more time than money and lots of scrap 3/4 OSB from flooring trimouts around stairs etc. - I ripped them to 2" & 2 3/4", primed and double painted all sides and edges.
Put 'em up on the corners overlaping, butted the siding up to the trim with about 1/8" gap, caulked the ends, ripped 8" Hardi siding in half and covered the corner base trim.
Been about 5 years and not a single problem.
Pedro the Mule
Now, that's the answer I was hoping to get. I had given some thought to the "woven" corners that Wayne mentioned seeing on TOH, but I prefer the corner trim boards that were original to this house. Everything I've read about fiber-cement seems to add up to a great product - IF it's installed right. It seems this method with the carefully prepared OSB (or similar) base would work well. OSB is, after all, what's under much of the siding done in recent years. The right caulk applied with care should make it work. Also, this one-story structure will be easy to monitor for trouble. Thanks as always for your help, folks.John