Nailing/fastening butt joints on cedar siding
GeoffPritchard
| Posted in Construction Techniques on
Putting up some horizontal rabbeted horizontal cedar siding and looking for help/ideas at best way to handle butt joints in longer runs of siding. Is worth trying to bevel the edges? How to weather proof without making a sealant mess at that joint is also part of the question. Thanks.
Replies
Flashing behind butt joints.....I bet if you ask siders of any age in most any area you’ll get a shrug of the shoulders and a quizzical look.
Butt, the word now for Hardie siding (and should be most board lap siding) would be to flash behind all butt joints.
Here’s something found that gives one opinion and one way to do it (not that it’s “The Way”, but it will give you an example. Old timers used to use a strip of 30lb felt.
https://activerain.com/blogsview/4770660/how-to-flash-siding-butt-joints
Another must is sealing/priming all sides, ends, and cuts before/during install.
And of coarse you need to look at rain screen......
https://en.wikipedia.org/wiki/Rainscreen
Tarpaper flashing is a good idea but for sure I would bevel cut the butt joints, it's easy to get a nice joint with a miter saw and it can be done with a circ saw.
Interior I’d do it.
Respecting the new age of the wood available now I’m going to lean on the side of smaller surface area with a butt joint. Trim probably yes. All this, respectfully.
I have another question regarding the bevel siding. IF I decide to cut the 45 miter at butt joints (as it is suggested in the actual siding product info that came with the material), what's the best way to cut the 45 in a piece of beveled wood? I thought maybe use a sacrificial piece of siding on top of the piece I'm cutting to make it a standard 5/4 board again but that seems burdensome. Any great solutions out there?
Sliding miter saw.
Flashing behind the butt joints is a good idea, although if you've gotten your WRB right it's more of a belt and suspenders thing. I used to do clinics for the Western Red Cedar Lumber Association, and I always refer to their installation guide these days. Go here for that: https://www.realcedar.com/siding/
Thanks to all of you for your responses.
Funny Andy should mention the WRCLA as I called them on Thursday and heard back quickly. They seemed to reinforce the basic things (ring-shanked siding nails, nail on studs, nail only at butt, prime/stain cut ends) but as how to handle the butt joints, it's a matter of preference (butt them or bevel cut them 22.5 or 45, single nail through the cut if beveled). No real comment on the flashing.
As a side note --- IF one chooses to use a piece of 30# felt behind each joint, would you try to make it work like a roofing shingle (top edge at upper edge of the siding and lower edge laps a bit up and over the piece below, still being hidden by the overlap.). I am using the rabbeted back siding BTW.
With your siding, the tarpaper won't work well because of the bend. I'd use brown aluminum coil stock and bend it to fit the lap with hand benders. But again, if you did your WRB well, this really is a belt and suspenders step.