CountryPlans Forum

General => General Forum => Topic started by: rsbhunter on July 17, 2013, 08:19:22 AM

Title: Built up beam for 2"x6" walls ?
Post by: rsbhunter on July 17, 2013, 08:19:22 AM
I am building a 16'x20' solar cabin that will be used as a temp place to stay and store supplies while i build my 20'x30' one story cabin. I am using BigFoot forms with either 10" or 12" pier tubes. 1st, which size do you think i should go with(tube diameter)? The solar cabin will house lead acid batteries  (6-8) , as well as the panels mounted on top. Also, if i have 6" walls, should i go with a 5-1/2" wide x 10" beam to support the 6" walls? Or will a 3-1/2" beam work? Thanks for any help...cabin is at 10,000 feet, so insulation is #1 priority...hence the 6" walls
Title: Re: Built up beam for 2"x6" walls ?
Post by: rsbhunter on July 17, 2013, 11:02:03 PM
Beams will be built up pt wood wwith plywood sandwiched between....
Title: Re: Built up beam for 2"x6" walls ?
Post by: rick91351 on July 17, 2013, 11:47:16 PM
Quote from: rsbhunter on July 17, 2013, 08:19:22 AM
I am building a 16'x20' solar cabin that will be used as a temp place to stay and store supplies while i build my 20'x30' one story cabin. I am using BigFoot forms with either 10" or 12" pier tubes. 1st, which size do you think i should go with(tube diameter)? The solar cabin will house lead acid batteries  (6-8) , as well as the panels mounted on top. Also, if i have 6" walls, should i go with a 5-1/2" wide x 10" beam to support the 6" walls? Or will a 3-1/2" beam work? Thanks for any help...cabin is at 10,000 feet, so insulation is #1 priority...hence the 6" walls

With out seeing your plans and ideas it is hard to come up with what you are thinking.  That said at 10,000 6" inch walls are a minimum and not a lot.  We are required 6" here at 5,000.

What are you engineering requirements when you pull permits?  Where are you at?  Here at 10,000 you are not going to build anything on piers without engineering stamps for both your foundation and trusses be it part time solar cabin or your 20x30.  What is your snow load there, and your wind load requirements?  How are you planing on fastening your panels to your roof?  I would think more on the lines of Mountain Don's or Jar Heads solar array but then that is me.  The last thing I want is something on the roof to drift more snow and more weight and more ice especially at 10,000 feet and huge winter winds pulling and straining on everything.   
Title: Re: Built up beam for 2"x6" walls ?
Post by: rsbhunter on July 18, 2013, 09:37:36 AM
Hi,  I 'm in southern Colorado....there is no inspections unless there is power or septic....of which there won ' be. The cabin is 16'x 20'.the back wall will be 16' high and slope down to the front wall. (South facing) at 10', like a lean to.there will be a loft area for storage.the piers will be at 6'4" on center (4 total)  with a 6" overhang on the ends for the end beams attachment. The front and rear walls will be the only load bearing walls. The loft will be at 8', with 2x10s on jack studs for joists....everything on 16" ctr 's.....plans are just my drawings.....that's why I 'm asking the experts here that have built..... Thank you.....rsbhunter
Title: Re: Built up beam for 2"x6" walls ?
Post by: SouthernTier on July 18, 2013, 11:12:10 AM
Quote from: rsbhunter on July 17, 2013, 08:19:22 AM
I am building a 16'x20' solar cabin that will be used as a temp place to stay and store supplies while i build my 20'x30' one story cabin. I am using BigFoot forms with either 10" or 12" pier tubes. 1st, which size do you think i should go with(tube diameter)? The solar cabin will house lead acid batteries  (6-8) , as well as the panels mounted on top. Also, if i have 6" walls, should i go with a 5-1/2" wide x 10" beam to support the 6" walls? Or will a 3-1/2" beam work? Thanks for any help...cabin is at 10,000 feet, so insulation is #1 priority...hence the 6" walls

Diameter of the tubes won't matter, but the area of the footprint of the tubes does.  Need to check your soil bearing capacity.

As for size of beams, guidance/tutorial here: http://countryplans.com/smf/index.php?topic=10511.0
Title: Re: Built up beam for 2"x6" walls ?
Post by: rsbhunter on July 18, 2013, 11:18:24 AM
Thanks, I did get 8 bigfoot 28" diameter footers...they will accept 10" or 12" tubes...the dia. Of the footers should be enough in undiisturbed soil...I plan on going 48" deep on the footers......rsbhunter.....After reading the link you included, i have decided to go with three 2"x12" beams, with 1/2" plywood between...the beam/girders will be in simpson brackets cemented into the piers, at no more that 18" above grade.....most at 12"....but any advice and help is great...Thanks again, rsbhunter
Title: Re: Built up beam for 2"x6" walls ?
Post by: Don_P on July 18, 2013, 12:53:53 PM
QuoteDiameter of the tubes won't matter
Push a blade through cheese edgeways and then flatways. The principle is the same, increased diameter equates to lateral resistance.
Title: Re: Built up beam for 2"x6" walls ?
Post by: rsbhunter on July 18, 2013, 01:24:23 PM
That is why I bought the BF28's. They accept the 10" and 12" tubes....fuggered bigger is better.....I had planned on using 12" tu es...,,..does the 3 2x12's for beams on 6'4" centers sound adequate? Thanks, rsbhunter
Title: Re: Built up beam for 2"x6" walls ?
Post by: SouthernTier on July 18, 2013, 01:36:00 PM
Quote from: Don_P on July 18, 2013, 12:53:53 PM
Push a blade through cheese edgeways and then flatways. The principle is the same, increased diameter equates to lateral resistance.
True, but I was referring just to 10" vs. 12" options.  Should have made that clear.  I am no expert, but I was figuring that for a 16' x 20' cabin, the extra 2" probably would not matter from a lateral stability point of view.  I suppose it would matter more depending on how far these stuck up above the ground.
Title: Re: Built up beam for 2"x6" walls ?
Post by: cholland on July 18, 2013, 08:10:41 PM
I used 3 2x8s for the center beam on my build. The pier spacing is 6' in the open living room and 5' where I have a load bearing wall.  You should look up the proper beam size on a wood beam sizing table (span table) Google it, there are quite a few available. I just glanced at the 2006 IBC and it seems 3 2x12 can span up to 8' on exterior load bearing walls.