Hardie Over Cupped Shiplap

pegasush

I am looking at my first Hardie install on a 100 yr old house. The house was sheathed with shiplap which has cupped. Renailing the shiplap flattens it some, but the wood is brittle, and generally cracks, and is still not flat. How much is this going to show through the hardie? How should the problem be addressed?

naptown CR

Do the client a favor
tear it off, insulate, sheath and tyvek and then put up the new siding

CScalf

ditto...

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pegasush

The owner had the building insulated previously when he reno'd the interior - insul, vb, drywall. I am sure I would not get a warm response if I suggest resheathing.

I have already stripped 3" of various siding materials. Hoping for a less drastic solution - furring strips?

woodworkbykirk

did something similar this time last year, wasnt my call just installing. i wanted to strip off the old, gc said just strap and side. i said hes gonna get a callback

curious as to how the house is holding up...

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knucklehead

Do you mean the shiplap is directly on the framing?

SLSTech

You can strap it (you need to make sure its plumb with no waving), but I agree with the resheathe

I would present both options to the HO under the good, better, best options

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pegasush

Yes the shiplap is directly on framing - old fir studs, hard as hell.

Had another go today at tightening the sheathing. Used a sheathing stapler, 2" legs. Worked a lot better at pulling the shiplap tight and holding it, but still far from flat.

Furring - what to use? I read one thread where everything down to a doubled strip of felt has been advocated. I was thinking of using 3/4 x 3" strips of ply - too much, not enough, or just right?

Javelin350

My Crew and I have ran into this problem before with an older house. What we did was rip down a few 2 inch rips of hardie for shims, then take your chalkline and put it flat on the wall to see what studs need to be shimed out. The hardie will float the bow in the wall. One bad thing about hardie is it will very easily show thw bow in the wall.