• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Structural redwood?

P

peesncues

Registered User
Joined
Oct 21, 2009
Messages
22
Location
Colorado
Our office has NEVER accepted redwood as a structural component (beams, joists) for decks as we have always understood that redwood had no structural value. Today I received an e-mail from a permit applicant stating that he had an engineer who will ok the use of redwood for his deck joists and support beams. I am reluctant to accept this proposal (even if signed and sealed) and am seeking opinions from this forum of respected experts! Any thoughts/advice?
 
Well, back in the day, Redwood had Table values in the 97 UBC 23-IV-V-1, from clear structural, down to utility. I know we used to see it used quite often, until PT lumber became the norm. If you have and engineer that will stamp it, then unless you can prove it is not valid, don't think you have to much room for rejection.
 
The code ref would be the supplement to the NDS, a free download on the awc.org site. No engineer needed, you can save the applicant a few bucks. The prohibition has been non code. The quick way is to hit their span calc... according to the NDS;

Maximum Span Calculator for Joists & Rafters

Then check against SPF, I think you'll be suprised.
 
One more thought, give the rules writing grading agency for redwood a shout, there's a contact link on this page, I'm linking you to their publications page;

Redwood Inspection Service
 
We're involved in the renovation of a 4 unit 2 story apartment building, an old one, real lath and plaster, and the whole structure is redwood. Redwood for years was one of the most common framing lumbers used on the west coast as it was the cheapest lumber to get. We've worked on numerous old houses and buildings and it's very common to see.

The floor joists on this project are 2" x 7.25", 16"o.c. and are over spanned by today's tables but there's no sag.
 
Your failure to accept redwood is not justified.

The IBC references the NDS standard which has design rules for wood. The NDS has provisions for design of redwood members just the same as for other wood species. The allowable values for redwood may be less thatn other wood species but such members can still carry considerable loads.

I am concerned that a building department would prohibit this perfectly acceptable material. Before taking such positions building officials should consult with an engineer. Do we have building departments that are not able to consult with an engineer on engineering issues?
 
Redwood is great stuff...for patio furniture...and you don't need an engineer for a picnic table...it's actually a preferred wood...for mulch, siding, doors and picture frames...not so much for beams and joists...of course if one has more money than sense... Shirley an engineer can make recycled newsprint Phil the Bill
 
Last edited by a moderator:
No engineer needed for these, it is acceptable within it's published limits. It is stronger and has better shear resistance than SPF but is less stiff. Take a look at the design values for cedar, white pine, northern species, eastern hemlock, etc. I had one BO tell me that the only hardwood allowed for framing by code was red oak. There goes any credibility. Look at the list on the AWC's span calc, that calc and those values are right out of the NDS and are what is behind the codebook tables. The tables in the codebook are simply abbreviated to the most commonly used species nowadays. I've done a good bit of heavy timber work in eastern white pine, I wish it had something remotely close to the strength numbers redwood gives. You could build with engineered cotton balls or grass clippings too, and we probably will, I've seen tanks drive on recycled milk jugs and red solo cups :)
 
fatboy said:
Well, back in the day, Redwood had Table values in the 97 UBC 23-IV-V-1, from clear structural, down to utility. I know we used to see it used quite often, until PT lumber became the norm. If you have and engineer that will stamp it, then unless you can prove it is not valid, don't think you have to much room for rejection.
Click to expand...
Yep, I remember those span tables. Redwood decks in CA are very common (or used to be). No reason to not allow use as long as deck is designed correctly.

Sue
 
Here's part of an old deck building handout from the city of San Diego.................. Well, the file size is too large and it won't take it but it has two columns for the span table, one for DF/L #2 and the other for redwood.
 
A lot of great information here and I appreciate it. That's why I turned to this forum. Thanks to all...
 
You must log in or register to reply here.
Top