Just the ends. Don't caulk the bottom. If water were to make it's way behind the siding and the bottom was caulked the siding would actually hold water. So just caulk the sides, but not bottom.

YIKES! Just stumbled across this thread. I don't know what the deal is, but I swear where I'm from there are some painters going around caulking the underside of lap siding! I seem to run across this all the time here. Never, ever, ever caulk the bottom of any type of wood siding.....EVER! Hehe! :cheesygri

I suspected that when I posted this. I have seen new wood siding installed and it isn't ever caulked. After a few years (like 40) you can get some big gaps from warping and customers aren't always willing to hire someone to fix the boards before we paint. My partner and I just wanted to make sure it was safe to leave these gaps.

AAPaint said:

YIKES! Just stumbled across this thread. I don't know what the deal is, but I swear where I'm from there are some painters going around caulking the underside of lap siding! I seem to run across this all the time here. Never, ever, ever caulk the bottom of any type of wood siding.....EVER! Hehe! :cheesygri

Click to expand...