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Nailing lap siding

Danno's picture

Okay, here's another possibly stupid question--when nailing cedar lap siding (I call it clapboards, some call it bevel siding--anyway its the horizontal boards that are thicker at the bottom and the one above overlaps the one below it by about 3/4 of an inch) aren't the nails supposed to miss (be just above) the board below the one you're nailing? Seems like nailing into the very thin tops is just asking for splits.

When we took the old ones down, they were nailed (thank goodness) so the nails didn't hit the one below. Since we removed the existing siding only to the tops of new windows, we could just slide the last board out from under the one above it (though the guy I work with pulled those nails too) and to replace it, we just slid the last board back under the last one that was still up. But all along and on the last one, the guy nailed through two boards at a time. Seems to me that this would split them.

As long as I'm asking questions: On plastic junction boxes, I thought you were just supposed to break the little plastic tabs but leave them attached at the top so when you slid the wire in, the plastic would hold tight, like a clamp, and let you push the wire into the box, but not let it be pulled back out (like a one-way air valve, but with wire instead of air). (Serving the same pupose as the screw clamps on metal boxes). But often I see the whole thing punched out, leaving just a hole that has to clamping ability. Is that right? Is clamping not necessary?

Okay, no more questions.

Edited 4/30/2007 8:35 pm ET by Danno

(post #103881, reply #1 of 4)

Regarding the bevel siding, there have been discussions about "double nailing" here before.

The cedar manufacturers definitely say NOT to double nail.  As you pointed out, splits are very common.  The other major problem is that the double nailing pattern traps the individual board; when it swells it will cup and/or split.  The nail is supposed to go throught the fat (bottom) part of the bevel siding, immediately above the fin of the previous course. 

I'm with you on the plastic boxes, too.  It doesn't make sense to completely knock the plastic out.  There could be code ramifications, too.


(post #103881, reply #2 of 4)

You are correct on the siding. Nail above the top of the board below.

Code requires wires to be stapled within 4" of the box. This effectively keeps the wire from coming out of the box. The tab you mention isn't a reliable fastener for the wire.

(post #103881, reply #3 of 4)

You're right on both counts.

Those plastic spring tabs are important on old work boxes, where it's often impossible to staple the wire close to the box.  Do nail on boxes have those tabs?  The ones I've always bought didn't have a spring tab, just a little knock out thing.


"When we build, let us think that we build forever.  Let it not be for present delight nor for present use alone." --John Ruskin

"so it goes"



"When we build, let us think that we build forever.  Let it not be for present delight nor for present use alone." --John Ruskin

"so it goes"


(post #103881, reply #4 of 4)

You may be right about the nail on boxes, we generally have been using boxes to replace others when we remodel.