More economical - timber or glulam 1

[whir]

I have a renovation that will use members about 20" long holding up roof loads. I have 3x12 timber as the joists. Does anyone know if using comparable glulam members is more or less expensive? The project is in the southern US.

 

[MiketheEngineer]

Timber is probably cheaper. Call a few suppliers and find out.

Have you considered LVL or wood I-joists??

 

[whir]

The job isn't in my area, so I'm not sure who to call to get accurate pricing info. I don't want to use LVL or I-joists because it is and industrial facility in a high humidty room. So, I though pressure treated timber was the safer bet.

 

[KBVT]

What part of the country are you in? Glulam is much more available on the west coast than in the east.

 

[whir]

The project is southern central US.

 

[boo1]

The engineering benefits of glulam wood products are reliability, dimensional stability, and higher strength,. Engineered wood is easier to work with than traditional dimension lumber, lighter in weight and consistently true to size. For many markets glulams are a stock product available from most lumber yards.

Large southern yellow pine beams will be simular in cost (if you can find them). Many large beams will be air dried and will shrink and check in service. When we ordered large 12x12 SYP beams they all were different size and many had bark on corners.

 

[msquared48]

3X12's may not be readily available - check with your supplier- and be more expensive consequently.

By the way, I assume you mean 20' long, not 20" long.

With GL members you could probably get away with 3.125 X 12's, or PSL 3.5 X 11.5 or 11.875, depending on your insulation depth requirements for the roof. I don't think they make the 2 11/16 sections any more.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[woodman88]

You can also spec a lumber size with a alternate GLB or LVL etc. sizes. Just make sure your details work for each size option. Then your client can find the best price.

Garth Dreger PE
AZ Phoenix area

 

[cslater]

Not sure if it would work, but you might also consider open web trusses...

http://www.standardstructures.com/products/ljc/sswow.html

 

[NS4U]

http://www.gostructural.com/magazin...nsional_and_engineered_wood_framing-7841.html

 

[Splitrings]

Check out apacheforestproducts.net. I have used 14"x14"x18' SYP treated timbers from these folks. They were $500 each last year plus shipping. We haven't found a glulam even close in cost. They offer structural grades also. They offer a 3x12 according to their website.

 

[csd72]

Be careful with glulam, not all of them are appropriate in moist environments.