Saw mill building - part two???

NCDiesel · January 23, 2014, 02:37:19 PM

I did not want to hijack the other thread, but my question is very similar:

I will soon build a rectangular 24'x14' building with a simple rafter/tin roof and no sides. I will use it as a saw "cover" (too small to call a sawmill building!!). I really need long exposed sides so that I can load logs and saw under that roof I want to. So I need to span both 24' distances. Basically; a very simple roof on 4 posts

I presumed two 2x12s sandwiching a plywood liner and then glued and screwed together would be enough. But after reading the other thread, I am beginning to wonder.

So I wanted to double check with you folks, who probably have a whole lot more experience with this than I.

jueston · January 23, 2014, 02:52:41 PM

i don't know your engineering loads, and i'm not an engineer. but i know that would fail here in MN. it would require something more along the lines of 3-14inch LVL's or 4 12inch LVLs.

2 - 2by12's would only span something like 10 feet in that arrangement here.

but if there is no code/inspections, and a little sagging doesn't bother you, maybe 2by12's would work....

1938farmall · January 23, 2014, 02:54:50 PM

ncdiesel, i just posted on the other thread about using a log header beam rather than spending money to reconstruct the beam out out of sawn lumber. this would only make sense if you were worried about appearance. i built a post-beam open side shed with a 22' span a few years ago & it looks fine. i'll send pic's if you like. al

thecfarm · January 23, 2014, 03:02:04 PM

1938farmall,where's the other thread? I might be doing something like this,but with a wood shed. But maybe only 16 feet too.

1938farmall · January 23, 2014, 03:16:27 PM

it's the thread by "peterob". al

thecfarm · January 23, 2014, 03:18:34 PM

Must be this one.

https://forestryforum.com/board/index.php/topic,72215.0.html

beenthere · January 23, 2014, 03:24:24 PM

Quotei'll send pic's if you like. al

We'd like to see the pics.

SPD748 · January 23, 2014, 04:20:26 PM

For my building, I'm looking at the metal truss system where the span is 10 or 12 feet between trusses. The company makes a 'bridge' that takes the place of a post making the span 20 or 24 feet. I'm not sure this bridging system would work on a building with only 4 posts though. It seems to me that arrangement would be a little shaky. My saw shed will be 24 feet (maybe 30 feet) by 70 feet with one bridge allowing logs to come in on the deck. With this arrangement, I'll have 15 posts holding things together and down.

A thought: Could you buy two 24' trusses then span the 14' with 2 x 8's or 2 x 10's instead of the normal 2 x 6's?

-lee

Den-Den · January 23, 2014, 05:41:46 PM

long span and only 4 posts makes me think that steel framing would be best for this roof. I would use pipe for the posts (6" or so diameter) and I beams for the long span. The short span could be wood or metal purlins.

dchiapin · January 23, 2014, 05:48:00 PM

manufactured trusses are not very expensive and they easily span 24'

Sawdust Lover · January 23, 2014, 06:58:49 PM

Im not sure what type of roof system you are using but a truss system can span 24'. I built my building for my mill which is in my gallery with pre fabed trusses and only paid $60.00 each delievered. I couldn't saw the lumber for that. At the openings where the logs come in I spanned 16' with a 4x8" white oak. I put it in a 4"x4" angle iron and screwed that to the beam. Then I put corner braces in and came in 3' with them so the span was really only 10' but the opening was 16'. I put a 12/12 pitch on the roof so snow would shed off. I am not a builder but this worked well for me.

scouter Joe · January 23, 2014, 07:48:16 PM

Like sawdust lover suggested ,if you have the hieght use a rectangular wood beam and posts . Then put in corner braces . If you go down and across 5' you cut 1o' off the span leaving a 14' span . scouter Joe .

dchiapin · January 23, 2014, 08:32:55 PM

This is what I am talking about, the span is 30', works great for my mill.

m wood · January 24, 2014, 05:17:44 AM

that's a fine looking shed. simple plan, nice detailing

Billbob · January 24, 2014, 07:10:48 AM

Wow! That is a nice shed! I may have to revisit my plans and steal some of your design.

Bill

kelLOGg · January 24, 2014, 07:20:06 AM

NC, if cost is an issue you can get utility poles (maybe free) to span that distance. You may get more snow load than we do in Durham so that is a consideration. The only cost of mine was the 5V galv roof.
Bob

bandmiller2 · January 24, 2014, 07:45:30 AM

Kellogs saw shed illustrates the value of angled braces they not only prevent racking but also reduce the span of the roof beams to a manageable load. If wood beams are used I prefer oak as it will bend not break. Frank C.

NCDiesel · January 24, 2014, 10:36:13 AM

KellLog and others on the log beams - I will definitely give that some thought Thanks!

I was going to span the 14' distance with rafters, but the idea of 24' trusses is intriguing. Will think about that. Thanks!

On advice of friend, I looked up span tables. A little tough to find post/beam beam spans that are not calculated with joists, but managed to find one. I would need to laminate three 2x12s and still have to use pretty wide corner braces (5' or so) as others have suggested to get this span down to a 3 piece beam limit of 17' and some change.

I have a sawmill (-: So I hate to but engineered products, but increasingly this is looking like the right way to go.