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I have heard it both ways: (a) butt the wood siding tight to your exterior window casing or next board to be installed or, (b) leave a small gap betwenn 2 butting boards and adjacent to the window casing and fill with caulk to allow for movement. Which is correct?
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I'd do it tight and - if possible - at least a 45 degree bevels at joints if not a 3 or 4" skeeved joint. But I am decidely old fashioned.
*Early home builders must have been incredibly stupid, as they butted materials together, not considering temperature induced movement, and they didn't ventilate attics. This explains why there are no pre-war houses still standing, I guess.
*Last time I used a 30 degree bevel, so the top piece was less likely to ride up. Worked well. Next time I'll put extra felt or butyl tape under the joint. Those long lengths of siding can open and close the joint 1/4" and I haven't found a caulk that can take it more than one season. And another thing. Don't install it over house wrap. It leaks. Next time I'm using felt and a rainscreen.David
*If you are using felt, what is the rainscreen? Something between the siding and the felt?Rich Beckman
*You got it Rick. The rainscreen provides a little air flow and drainage behind the siding. I found an open web plastic furring strip that will give me about 3/16" and will staple to the studs over the felt.David
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DAVE, can you describe this rainscreen further? How close to windows, layout / spacing / vert or horiz. and what is the material. I don't understand open web plastic furring. Thanks, Kelly
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Kelly,
The furring is simply stapled or nailed to all studs over the felt. Then the siding is nailed to those same studs over the furring, thus leaving an air gap the thickness of your furring. This is usually done with wood lath, but I think the plastic mesh will be quicker and can also be used as a screen at the top and bottom of the walls to prevent insects from entering while still allowing drainage. The product is manufactured by Plastic Components (800-327-7077) Talk to Karen in customer service and ask for PDM, cut to 1-1/2" wide strips. It cost me $.057 per lin.ft.
David
*Buzz,There are a few siding / casing / trim details I've been trying out based somewhat on Joe Lstiburek's (Building Science Corp.) ideas and details. (see Builder's Guide for Cold Climates)The details depend on the type of windows you are using; new construction or remodeling; installed yet or not......In some cases you could butt tight and in others you would actually put the casing over the siding. All depends on your situation.As some have noted above, rainscreens are the way to go. And no matter how you do the details you should prime the siding and trim on all 6 sides before installing.Caulking should only be used for making it look pretty and only when necessary. Never use caulking to keep water out.
*Buzz, butting the siding tight to most windows will void the warranty! Additionally, most siding manufacturers will also void the warranty if you don't leave the required clearances!Do yourself, and the homeowner a favor, and find out the technical requirements that each manufacturer has established for it's products. Most lumber yards have the info stashed under the counter. The manufacturer's rep will come to your jobsite and thoroughly explain the installation process. At the very least, they will call you (if your up in the north pole). Call the 800 number or look them up on the web.Don't however, lay siding tight! It is an old fashioned idea, one that is wrong!blue, maintaining all warranties in MI"It's as BAD as you think, and they ARE out to get you."
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I have heard it both ways: (a) butt the wood siding tight to your exterior window casing or next board to be installed or, (b) leave a small gap betwenn 2 butting boards and adjacent to the window casing and fill with caulk to allow for movement. Which is correct?