Warped Siding

[David Block]

House I inspected today is pretty much the same as most houses up here with the same crappy hardboard siding. The siding was warped at several sheets on each side of the hosue. 17 year old house, zero maintenance performed on the exterior, the extra nails visible at the bowed sections in the siding were obviously an attempt to "repair" the bows in the siding. I have spoken to several siding contractors in the past as well as some other inspectors but I don't seem to get the same answer from them. Some say it is a defective product, some say the nailing pattern was incorrect while other insist that the siding was not gaped properly at the z flashing so what is the right answer? I have my theories but I'd like a more experienced opinion.

[Jerry Peck]

The panels were wedged in tight with no room for expansion AND were not nailed properly.

The bowed out section is now not nailed at all.

Even properly nailing will not necessarily keep that from bowing out when it expands - the ends are pushing tight against the stops at each end, something has to give someplace - so it pops out some nails (or simply pops out over the nails), leaving the bowed area.

About the only repair is to cut back one end to relieve the pressure and allow room for the panel to be laid back straight (if it even will) and then re-nail the entire panel, making sure to have space at each end of the panel for expansion.

Other than the above, replacement.

[David Block]

Thanks Jerry. I was thinking along those lines as well. I see all the time where the upper sections of siding are wedged in tight against the flashing at the lower sections of siding. When the siding decides to expand and contract it doesn't exactly have anywhere to go but out. Am I the only one who actually reads the instructions provided by the manufacturer requiring...I think it was a 3/8" gap. Not to mention the expansion and contraction but what about painting the drip edge....its kinda hard to paint the edge of the siding if its packed in tight like that. I think in part it is also the nailing pattern as I often see the nails at the perimeter 12" oc or more in lieu of 6" oc. Sometimes I see little to no nails in the field. My question is, do city inspectors not pay any attention to the installation of siding materials?