The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: Coach on April 14, 2017, 09:30:32 PM

Title: Does this plan look fine?
Post by: Coach on April 14, 2017, 09:30:32 PM
Can you guys take a look at the pic, see if my plan to tie or hold in the sides is ok (sorry, but I don't know the correct terminology).  It'll be a 18' x 12' open structure with roof, using 8" round Oak logs.

(https://forestryforum.com/gallery/albums/userpics/31914/image~5.jpeg?easyrotate_cache=1492218637)

Title: Re: Does this plan look fine?
Post by: Den-Den on April 15, 2017, 11:48:50 AM
IF the vertical posts are securely buried in the ground (aka pole barn): there will be a good bit of outward thrust on the wall plate logs but with 8" logs and only 12' span, my gut says you will be OK.  If the vertical posts are secured only with brackets, my guess is that the whole thing will blow over in the first wind.
Title: Re: Does this plan look fine?
Post by: Roger Nair on April 15, 2017, 04:17:22 PM
Sorry Coach, that's no plan.  You will need to put more in to get meaningful output.
Title: Re: Does this plan look fine?
Post by: MbfVA on April 23, 2017, 07:06:00 PM
I would not omit footings for your columns
Title: Re: Does this plan look fine?
Post by: MbfVA on April 23, 2017, 07:13:20 PM
We want to do the same thing at our farm and have seen several videos on YouTube showing the process.  Most localities don't require permits for farm structures but I would suggest you do what the OP suggested and get more engineering detail on paper before proceeding.  Nothing like transferring the risk to a PE or similar designer.  My understanding is these things are not really complex but as with any big structure if you do not want to have it collapse from wind or other consequences of nature's toll on bad planning/design, have your plans vetted professionally--probably won't cost that much if you do as much as possible beforehand (watch several of those videos, etc) and do the dog work for the pro.

I'm a retired CPA.  Come to me with a shoebox and you'll pay more.  Arrive organized and save.
Title: Re: Does this plan look fine?
Post by: florida on April 24, 2017, 02:56:40 PM
Even with a structural ridge you'll need something to resist spreading from snow load. If you don't want joist you could use cable for the bottom chord.
Title: Re: Does this plan look fine?
Post by: MbfVA on May 29, 2017, 05:29:48 AM
couple of related design questions for this thread:

Instead of footings for each wall post (wood in concrete in the ground sounds too much like bad fence post practices, even treated; isn't it going to rot eventually?), could it work to set bolts in the floor and anchor a plate, maybe a 4x6 (thinking, cut from our woods, no rm cost), to the bolts, then tying the posts to that plate?  I'd treat the floor plate material since it would be in contact with concrete.

What is the maximum width span for a utility building considering we want to use our own lumber and not have to use anything engineered or complicated?  40 ft is one figure I have been told.  Trying to get a lot of floor space as economically as possible.

As I advised the OP we will definitely get a PE & our designer happy with what we do.  At this point I am trying to work out rough parameters.

All thoughts & comments welcome and appreciated.  We'll get going on the hse we want to build soon as we get the util bldg done.  And our sawmill bought.

Thanks from central VA on the great Rivanna River or Rivah as some around here say.  or is that "around heah"?  I give up.
Title: Re: Does this plan look fine?
Post by: sandsawmill14 on May 29, 2017, 07:13:14 AM
 

 (https://forestryforum.com/gallery/albums/userpics/38145/20161022_221256.jpg?easyrotate_cache=1477192757)

i built mine 24' wide and 30' long and used 2x8 rafters on either 24" or 30" inch centers(cant remember ::) ) it is built on 4x4 treated pine post with a post every 10' buried about 30" deep :) every rafter is tied about 3' down from the peak (done this for overhead clearance side walls are only about 9 1/2 ft) if wall was taller i would have used 6x6 instead of 4x4 and roof is on a 4/12 pitch :) no roof sag or other problems yet but it was has only been built for 21 years this summer and the biggest snow load it has seen was 10-11" so i dont know how long it will hold up ;)

just for the record the steel beam in pic is a 4000lb overhead crane and is not part of the building structure at all it was added 3 or 4 years ago :)

there is no way i would build a open post type shed (pole barn/shed) on a slab with the post anchored on top of the concrete unless it had alot of steel to tie the post and wall ties together even the engineered buildings such as morton buildings bury the post but all i have seen use trusses instead of rafters  :)  i have never seen a building built on top of  slab/footing UNLESS it had interior walls then there is no problem ;)  i dont know about the post and beam construction though it may be different but i do know about the pole barns we had an old barn collapse about 5 yrs ago that was built in the early 1920s on round cedar poles  :o  if mine stands that long i will be satisfied but i will be like my great great uncle who built the barn and will never know how long it stood as he had been dead for 50 years when it fell :D :D :D
Title: Re: Does this plan look fine?
Post by: Don P on May 29, 2017, 09:48:34 PM
MbfVA, You have a code issue that might pop up. The ag exemption is for the farm where actual farming operations are taking place. Your building dept will most likely have an ag exemption affidavit that you will need to complete, if so don't get yourself into hot water to save a nickel.

There is also an accessory structure exemption for a 256sf max utility building that is accessory to a residence that is already in place.

What I'm saying is this sounds like a permitted rather than an exempt structure, which if a design pro is involved is no problem.

A post framed building usually picks up lateral resistance from the posts being embedded in the ground, but it doesn't have to. When the lateral restraint is not provided by the soil then that bracing needs to come from somewhere else, walls, braces, moment resisting frames. You can build above ground, the devil is in the details.
Title: Re: Does this plan look fine?
Post by: MbfVA on May 30, 2017, 04:25:24 AM
We have an SL-6 on our land (stream exclusion, $97,533 from VA taxpayers), cut hay in the past, had cows and will have more, and our BI takes little interest in farm bldgs but we would want to do it right.

When I was on our Goochland Board, we even blocked charging for permits farm structures as I recall, and the BI told us most go up with no permit anyway.

That was years ago but VA ain't NY or CA.

Fluvanna has money & staff problems, so like IRS which is in the same boat, they possibly aren't quite as aggressive as they once might have been.  Umm, IRS will surprise us so maybe I should temper that as the good retired CPA that I am, but their sharper teeth are fewer in number.

Which county are you in?  I recall something about SW VA? I grew up in Salem.
Title: Re: Does this plan look fine?
Post by: Don P on May 30, 2017, 07:07:17 AM
Yup enforcement is highly variable, I can cross 30 years of attitude shift in a very few miles. Not NY or CA but some do think we're in Richmond for whatever reason  :D I'm down in Grayson. I know the way to Salem well, we either end up running down to Winston or up to Salem for big doctor visits.