Maximum Lengths for Sawn Lumber

[Loui1]

Is there any good sources out there for the maximum available lengths for sawn lumber? Such as, if I use 2x12 rafters, how long can I get them before I have to go special order or it becomes not available?

 

[SlideRuleEra]

Lengths up to 16' are easy to find. Beyond that, check with the supplier, for example Georgia-Pacific offer Southern Pine in lengths up to 20' and Douglas Fir & Hem Fir up to 24'. Here is a link for reference

http://www.gp.com/build/product.aspx?pname=Softwood+Lumber&pid=1394&hierarchy=pc

The American Lumber Standards Committee does not address length, other than specifying 2' increments. Here is the "American Softwood Lumber Standard"

http://www.alsc.org/greenbook collection/ps20.pdf

http://www.SlideRuleEra.net

 

[Loui1]

Thanks for the info. The problem is, I'm in the design phase and dont know who the supplier will be. I'm looking at 21' spans, so I will probably go another route than solid sawn.

 

[jopalu]

Contact a reputable general contractor that you are familiar with. Find out where they purchase lumber from. If it is a retail lumber outlet, find out what wholesaler they purchase from and call that wholesaler.

Another thing to consider is how straight will a 22' length piece of lumber be?

Consider TJI's?

 

[cvg]

not very straight! I'm working with 8' studs on a framing project right now and it is difficult to find straight ones. For a 21' span you would be better off with an engineered product.

 

[dik]

I did a report on an old barn. The main floor timbers were 16"x14" by 50' long...

 

[DaveAtkins]

I think it would be hard to get dimension lumber studs to work at 21' height, anyway. I think an engineered product would be better (but be careful--Timberstrand has an E of 1,300,000 psi, meaning it deflects more than S-P-F!).

DaveAtkins

 

[DaveVikingPE]

dik, do you have photos? Those are awesome beams.

Regarding the long rafters, consider scissor trusses maybe or other type products. Maybe glulam ($$$).

 

[ctcray]

We have 2x12-24' SPF in stock in our yard right now, but per foot, an 11-7/8" I joist will be cheaper per foot at that length. (and straighter....and more available in large qtys.)

 

[dik]

Should have... I'll try to find them... it was the Frank Barn, just outside Fowler's Corners, Ontario... Also did a report on a building near Fenelon Falls, Ont. The width of the roof sheathing was 32"...

Dik

 

[Lutfi]

I visited a historic school in south Florida last week that was built in the 1920s. They used on the roof framing 2X8 and 2X12. The lengths varied from 28 to 40 feet long!!!!!!!!

Of course the school was built in 1920s.

By the way, anyone has published date on Miami-Dade pine?


Regards,
Lutfi

 

[SAVAGE54]

2X12 22 feet long should be availbe by special order at any contractor's yard. My family has a few building supply yards and I have commonly work with members 22ft even up to 26 feet. I work in Nashville and the supply yards here commonly have it in stock.

As a designer, I would be concern about the deflection of a memeber 22 ft long but looking at SPF span charts.

http://www.southernpine.com/pdf/table02.pdf

With a 40 LL 10 DL Loading L/360
A 2X12 #2 @ 12" o/c is good for 21'-9" CLEAR!!! My have to require a #1 but not a uncommon requirement