Proper nailing method, cedar clapboards
I’m planning on residing my house with 4″ red cedar clapboards. When I say 4″ i would special order full 4″ vs. nominal (3.5″). The red cedar trade group (WRCLA.org) says there should be a1″ overlap, and then the nail should be driven just low enough on the board so it just misses the top of the underlying board. Thus each board at each stud is held by one nail. My concern is this pattern, at 1″ up the board,and at the top edge of the underlying board, imposes a lot of stress on the board at that edge which will ultimtely lead to a crack. Now the WRCLA says you do it this way (missing the underlying board) to keep the underlying board from splitting. And visually, with a 3″ EXPOSURE, the nail 1″ up the board looks a bit extreme IMO.
Any opinions. Guys that I now who have been doing this for years disagree with this method.
Replies
I like the trade group spec..
I've always preferred the look of properly placed nails in face nailed boards. Some of that preference comes from the form follows after function school, as there is rarely a case when the blind nail is more effective, structurally.
We do a lot clapboard siding here in New England. I've done a ton of them in all the different ways. I can walk down the street past homes from the 1700's and see the original white pine clapboards and how they were installed. I can also walk past homes built recently with red cedar clapboards. Within a few years, the new ones are having issues and it's not the species. I like to use white pine and do it the old way, smooth face out, nailed through the butt up about 3/4", every 8" + -, hitting studs and in between. I started building in the 60's so I can look back at my own work and see how things have stood up. I do red cedar the same way.
Pictures are worth a thousand words and so is long term experience. I built this house in 1980, 1/2" x 6", 3 3/4"- 4 1/8" to the weather, installed as above, over red rosin paper, 1/2" CDX sheathing. We didn't have house wraps, OSB and I didn't back prime. Installed, coat of oil based primer, two top coats. It's been repainted a few times, different colors, different products but usually with a solid exterior stain, both oil and acrylic. Here are some before and after, hiot the expand button for close ups. It's a little past time for another paint job, it's been 10 yrs. I think this is the 5th paint job in 32 years. Not quite as good as new but relatively unchanged, still tight, easy maintenance. I don't see this on many of the other houses I've built with rough side out cedar, nailed above the top of the preceeding clapboard, only on the studs. Instead I see curling, splitting on the nail line especially on ends, nails pulled out, more degradation and fading, even factory finished over rain screen. I don't care what the cedar bureau or others say, I think my method is working very well.
lot of variables
Here's the deal.
If you nail low, it secures the cracksiding tighter. But if the wood is damp or green, it will shrink. When it does that, toightly nailed siding will crack, because it is nailed tioght at top and at bottom, so the shrinkage places the strress in the middle.
Nail higher and light, and any movement of the wood is free to happen without hurting it.
So IF you are going to nail low and tight, the siding MUST be dry and very well back-primed, preferably with oil based primer/sealer. With red cedar, this can also help prevent bleed through on the surface finish.
There is one man's opinion.