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Discussion Starter · #1 ·
I'm going to be building a pergola-style patio cover. This will be attached to the house on one side, but the other side will have a beam, probably 6"x8"x14'. Rafters will be 4"x6"x11'. Posts will be 8" round. I'm wondering what the best wood to use is, that would result in the least amount of potential warping. It will probably be Ponderosa Pine or Douglas Fir. Green or dry? I might be able to get KD Doug-Fir locally but I haven't checked. I'd rather not use a glulam or LVL. Suggestions?
 

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Both the pine and fir will be suseptable to rot and insects. It would be a lot more durable to use pressure treated pine. The wood will stain well but will be a little darker.
 

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I would use treated for the stuff you can't see and don't walk on and clear cedar for the deck. Any wood can warp so you just have to use good building practices and for heavens sake protect it with some kind of sealer, stain or paint.

Al

Friends don't let friends use stamped metal tools sold at clothing stores.
 

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Discussion Starter · #4 ·
I should have mentioned that I'm in NM and it's so dry here that rot is not an issue. About the only thing we use PT for is posts that are buried or set in concrete. My posts will be on 1" stand-offs to meet building code. We don't have a lot of trouble with bugs either. Our main problem is warping. In early summer RH is usually in the single digits (I've seen it at 1%, as low as my thermostat can measure).
 

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Douglas fir would work then. I think it would be less likely to warp than ponderosa pine. It would be best if you select fir boards that were especially light in weight. The heavier they are the more pitch they would have and more prone to warp.
 

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Discussion Starter · #6 ·
I'm going to check with a local lumber place about Douglas Fir, and particularly what they have that is dry. I've read the info about difficulty kiln-drying beams larger than 4x. I know of a couple of places that sell green Ponderosa Pine, but based on what I've seen, warping is a major problem with green PP.
 

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.....In early summer RH is usually in the single digits (I've seen it at 1%, as low as my thermostat can measure).
So that's why they call it a dry heat. The only thing I've seen in the 1% range around here are interest rates on money market accounts! :thumbdown:

Good luck with your build....please post pics! :thumbsup:
 

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Discussion Starter · #8 · (Edited)
OK, I've attached a couple of pics of similar porch covers. You can see why warping can be a big issue here. Some of these timbers are just toe-nailed, so if the wood wants to warp, it will. Mine will be lag-screwed with 1/2x11 or larger lags on the 6x8 beams and corbels, and 1/2x9 or larger lags on the 4x6, but even then the wood may have it's way. I know some guys like to use green PP timbers for this and bolt it down hard while it ages. I guess sometimes that works.

Edit: I'm going to skip the fancy carved posts and just use round ones. That way if they twist, you can't see it.

Edit2: The lumber is these is green PP, and I know the source.
 

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Discussion Starter · #10 ·
I plan to have 4x6 rafters bearing on a 4x6 ledger (on the house) on one side and on a 6x8 beam on the other side. The rafters will be lag-screwed through the top of the rafter in to the ledger and beam. The roof slope is 1/2" in 12". Do I need to cut a bird's mouth on the rafter? IRC says I need a 1.5 inch bearing length, which I'm not going to get without the bird's mouth, but I've heard that you don't need it with a 1/2 in 12 slope.
 

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Discussion Starter · #14 ·
I found a 6x8 18" DF #1 at a local lumber yard. The guy said it's been sitting outside (covered) for a couple of years and they haven't sold it because one end (about 1 foot of it) is a little deformed. I'm thinking this is perfect if I can get a good price on it, as it's totally dry by now. I only need a 14 footer, and I can just cut off the end(s).

What do you think?
 

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Ipe, Wester Red Cedar, Red Cedar are quiet the best. Usually Ipe is the most recommended for patios.
@Garya505 if the guy is near by, visit him and look into the stuff. If you found it perfect then buying is the right option here. If you need an experts advice or help go get new patios contact all about shade, patio covers.
 
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