My house is sided with 5 1/2″ red cedar clapboards. The exposure is 4″. I have read that when face nailing that the nails should be placed so that they are above i.e. do not penetrate the overlapped boards. Based on nail location the nails penetrate the overlapped boards. Wouldn’t placing the nails higher up so that the overlapped boards weren’t penetrated potentially allow for cupping?
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What actually allows for cupping is significant wood moisture content changes in plain sawn lumber.
Siding is milled flat, not cupped. So if your lumber stays at roughly the same moisture content (MC) as it is milled, then no cupping should take place. If the MC increases significantly the grain will swell and the board will cup. Nailing in only one location allows for this movement (primarily gain along the width) to take place freely. If it is retrained at two positions it can actually increase the amount of cup as the stress looks to be resolved by "getting away" from axis of restrait. Conversly, if the wood is installed at a significantly higher moisture content then service, then it will shrink and possibly check along the grain or split when fastened at two positions. At the very least shrinking and swelling will tend to work loose fasteners that are restraining siding nailed at two locations along it's width axis.
Theoretically, if the siding never changes M.C., then it doesn't matter how manly locations it is fastened along the width axis. However, in the real world, no matter how well you seal the grain, moisture content changes can happen and those are the reason(s) why it is recommended to fasten in only one loation right above the lower course. This pins the bottom of the board while "clamping" (not restraining) the top half of lower course.
Deadnuts
Thank you. I understand your explanation. How would you describe this installation? Unprofessional? Didn't know what they were doing? I recently replaced some siding ( front door water leak post) and followed the exposure and nailing spacing so I guess I repeated the original installe'rs incorrect technique. Live and Learn.
You bring up an interesting question of how things get done a certain way.
I've seen many carpenters simply striving to learn "how" things are done. In my opinion, if they focused more on understanding "why" things are done, then less mistakes would be perpetuated.
finefinish
Thank You for your input. I'm in New England so it looks like I have the New England method.....house is 28 years old, clapboards are tight and in good shape. It was a spec house and the siding was already on when we found it. One thing I liked was that the GC put clapboards on all 4 sides. I see a lot of houses with clapboards on the front (show) side and shingles on the other 3 sides. My previous house was shingled......a lot of work to scrape and paint.
House Siding
So Not Cheap would be brick on all 4 sides? I'm not sure how it all works. I was told that shingles are less expensive than cedar clapboards. Easier to install shingles? Also, once wall-to-wall carpeting was invented wasn't that the sign of an upscale house? Now hardwood floors are back in style. Wide or narrow lapels and neck ties?
Shingles 50% more..
My estimating books and some quick looks on the interweb show installed cost of cedar shingles to be 50% more than cedar clapboard..
Also...back to your original question...the fact you are using relatively narrow siding works in your favor as well. Cupping is also affected by the quality of siding available today. Clear vertical narrow grain cedar is much more stable and less likely to cup than most of the siding available today (and much more expensive). Boards with face or open grain (you can see the circular rings and open grain on the face of the siding) is guaranteed to cup if only nailed at the top.
My estimating books and some quick looks on the interweb show installed cost of cedar shingles to be 50% more than cedar clapboard..
Depends on how much the shingler is being paid, doesn't it?
wmheinz
Looks like I got some incorrect info.....guess I asked the wrong sub contractor. So why clapboards on the show side (front) instead of shingles? Better look with all the front details?
Used to be that shingles were cheaper than claps (especially when the shingles were some sort of old-style composite), and labor was almost free.
Almost Free Labor
Please explain that one.
It means that the guy hanging shingles didn't get paid very much.
finefinish
Thank you for the explanation. Makes sense. I learned something new today.