Engineered lumber prices

Started by Dberry, May 17, 2006, 01:28:49 PM

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Dberry

Greetings all!

I got a quote yesterday on some TJI's to span 24'.   They are roughly 100 dollars each and the designer spec'ed them for 16" on center.   Total cost was 2800 just for the joists.  This compares to $400 for sawn lumber on 24" centers (half the span).  I was surprised at how expensive the manufactured lumber was.  

It was a reputable yard and thier price was $4 per foot.  I had expected a small premium for the TJI's, but found this shocking.

Is this typical?  

Dan

nandajor

Hi Dan.  Just so happens, we were checking on engineered joists last week, when in Colorado.  A guy that we met, gave us his figures from a lumber company  and I believe, Lowe's.  The "brochure book" we have is RFPI, Roseburg Forest Products.  Both estimates, worked out to more like $2.00 a foot.  This was not so out of line, with the lumber figures that we had previously figured.  The man, who was already starting his cabin, was spanning 28 feet, but was required to have a girder beam at 14 feet, (he was building that girder of three sandwiched 2"x10"s) on concrete footers down to the frost line.  I am not sure if the estimate was from Lowe's, however, he did have two different ones and they were both under $2.00 a foot.  If you actually are spanning 24ft., I am sure the cost would be higher.  Good luck, Nanda


rwalter

I am not sure I understand your span size you wish your joists to go. I believe most places that the miniumum code for first floor living space is a 40/10  (live/dead load) with a L360 deflection rating for floor joist. This however will proabably cause a rather bouncy floor. If your trying to span 24 feet with a single joist you pretty much have no choice but to go with an engineered joist.  Even Structural Select rated Douglas Fir at 12 O'C' will only span 23' 3' at a 40/10 load with L360. I would never recommend using them even at that distance. At that span size you should probably be looking for at least a L480 or L600 deflection rating and you'll not get that with dimensional lumber. So your best bet is running a supported center beam down the middle of the span. Then you could even use #2 grade 2x10x12 SPF, Hem Fir or Doug Fir and easily meet 40/10, L600 deflection.


http://www.awc.org/calculators/span/calc/timbercalcstyle.asp


Good Luck

John Raabe

#3
For a 24' wide span you are usually far better off dropping a beam at 12' or so and using lumber joists. This is what I have done in the 24' wide Solar Saltbox. I usually try to line these 6" deep wood beams up on exposed 6x6 posts for an internal post and beam look. Connect the beam and posts with bolted steel plates and they look quite sturdy and handsome.



On my 20' wide plans you can use the more common (and inexpensive) 9-1/2" TJI's for a full 19' span. However, I also have a framing plan with a beam and standard joists since some areas of the country will find that to be less expensive.

For really long spans you can also look into web trusses (deep configurations built up from 2x6 or 2x4's). These are expensive but allow you to have the big open spaces needed in commercial installations.
None of us are as smart as all of us.

Dberry(Guest)

That's exactly what I've done.  :)

I originally designed the floor with 12' spans on either side of a central beam.   After pricing the the beam, posts, and joists, I decided to call the lumber yard just to see what 24' joists would cost.  I was just shocked at the premium.  Since I'm not worried about a couple posts in my workshop, I'll be going the standard lumber route.

Dan
(not sure if this will work from work)