Does exposed wood framing covered under porches and canopies need to be treated?

[abusementpark]

What do you think? Is there a consensus on this?

 

[TomDOT]

Depends on the climate and expected lifespan.

If it's my porch, it needs to be treated.

 

[frv]

I agree with TomDOT on both sentences.

 

[dhengr]

If it is likely to be wetted frequently, and dry slowly, it should be PT’ed. That would be decking, floor boards, joists, ledgers, posts, etc. which are openly exposed to the weather. I put peel-n-stick tape or felt on the top edge of deck joists before applying the decking. I also top flash multi-ply beams. It is these wood-to-wood contact points which do not dry fairly quickly Covered roof trusses and/or t&g ceiling boards, and the like, which will not likely see anything other than the ambient local humidity should not need to be treated; but they might best have some surface finish, all sides and ends, which limits moisture intake.

 

[dhoward26]

IBC 2304.11.2.7 Posts or columns states the following:

Posts or columns supporting permanent structures and supported by a concrete or masonry slab or footing that is in direct contact with the earth shall be of naturally durable or preservative-treated wood.
Exceptions:
1. Posts or columns that are either exposed to the weather or located in basements or cellars, supported by concrete piers or metal pedestals projected at least 1 inch (25 mm) above the slab or deck and 6 inches (152 mm) above exposed earth, and are separated therefrom by an impervious moisture barrier.

 

[abusementpark]

If it is likely to be wetted frequently, and dry slowly, it should be PT’ed. That would be decking, floor boards, joists, ledgers, posts, etc. which are openly exposed to the weather. I put peel-n-stick tape or felt on the top edge of deck joists before applying the decking. I also top flash multi-ply beams. It is these wood-to-wood contact points which do not dry fairly quickly Covered roof trusses and/or t&g ceiling boards, and the like, which will not likely see anything other than the ambient local humidity should not need to be treated; but they might best have some surface finish, all sides and ends, which limits moisture intake.

So if covered, yet exposed roof rafters in a open canopy only really get a little wind-driven rain, they don't need to be treated?

 

[TomDOT]

Some of that depends on the design - for example, while most of the rafter could be well covered, but rafter ends at (or close to) the dripline then lead to rot from exposed end inward.

 

[a7x1984]

We limit untreated lumber to be contained within conditioned spaces only.

In Russia building design you!