8x12 woodshed question

[Hemlock121]

Hi.  I have never built a timber frame building but life is getting short so I thought I would build an 8x12 timber frame woodshed. Would I build the floor system with joists 16" on center in 2" pockets or could they be at a greater span?  I may store my ATV in the shed over the winter and it weighs approximately 800 pounds.  Would I reduce the joist span where I might store the ATV?  Last question.  I have a hobby sawmill so will mill up red oak for the floor.  With the potential weight, should I use 6/4 material or could I get away with 4/4 material?
Thank you for your input.

[Don P]

Thoughts on my way to bed.

The thickness of the floor boards partly revolves around the spacing of the floor joists. Figure no less than 300 lbs on a flatways board. If someone is going to run in and stab the brakes, double that.

 I don't think it would be wrong to figure half the weight of the ATV plus a bit perched midspan on a single joist, say 500 lbs and use the midspan point load calc in the red toolbox, bottom of the left hand column on this page. Start there and holler if you get stuck.

All that said.. I'd go with diagonal plump 4/4 and  2x8 joists on 16" myself  :D. Borate the oak or the beetles will move in.

[Brad_bb]

So, when you call it a woodshed, will you also be storing firewood stacked floor to ceiling?  Or is it just a tool shed?

[Hemlock121]

I will be storing firewood floor to ceiling.  If I can separate out a 54" ish area for the ATV (ATV 48" wide), that would be a bonus. So perhaps 7+' for wood and 4+ feet for ATV?

[Brad_bb]

Will your joists span the 8' direction or the 12' direction?  Will the joists attach to timbers or will it be a stick framed deck with the posts going into pockets on top?  What will your structure rest on?  Piers?  Even though you're in Arizona, I know there are parts that get snow and wet.  So I assume you're going to get airflow under there, but now sure how you keep rattle snakes out?!

Also what joist material do you have available to you?  You'll want span tables to try to figure out how much load they'll be able to take.  You should also calculate how much weight per square foot the firewood will be.

[rusticretreater]

If you use some concrete joist supports, you will have zero issues and can use 2 x 8 joists on 16" centers.  I built a 16x16 shed with them and the floor is rock solid.  Lay 3/4 flooring perpendicular to the joists and you can put anything you want in it.

https://www.homedepot.com/p/7-3-4-in-x-10-3-4-in-x-10-3-4-in-Concrete-Deck-Block-100002709/204827028

[Don P]

Those are not even legal for a deck...

[Hemlock121]

I went to a big box store last night and walked through their 8x12 shed and after thinking about my use,  I will have to make the woodshed 8x16. 

Brad_bb.  I will be making this at my place in Ontario so was thinking about using 8x8 sill beams from red pine and run 5x7 joists perpendicular so in the 8' direction.  I will pour concrete 4' under grade for frost protection and then place a CMU block on top of the piers to keep the structure off the ground. Since this is for wood and ATV storage, could I get away with making the posts and tie beams 6x6 or 7x7 or if I use 8x8 for the sill, then I need to keep with 8x8? 

There aren't any timber frames here in Tucson where I live to look at for comparisons so appreciate everyone's input.  I'm in my mid 50s so want to build this once.

[rusticretreater]

Those are legal for a shed floor support in Virginia.  It does pass inspection.

[Don P]

It looks like  Hemlock is going a different direction which is good.

The deck block "passed" inspection on a shed. Only in the sense that below 256 sf for an accessory structure it is exempt from foundation requirements in VA.

In its use as a foundation, it is less than one square foot of bearing surface on the ground, that is a serious limitation when talking about a relatively heavily built and loaded shed, exempt or not. I'd have to look but I think a deck, which is not exempt, the minimum footing is 18" square. I find it easier to just do a 2' square minimum on about any pier and figure between my dead load and your treasure that snowshoe is good for about 4 tons in most dirt. Rocks here are pretty near at hand. It is not hard to make a substantial foundation.

[Brad_bb]

I like to use full dimension timbers in timber framing.  Being that you'll be 8x16, Proportionally I think 8" timber would look and feel correct for that size.  That is in the size range of what is typically 8" timbers, but I also recommend using a plan that is engineered or getting yours done.  rjwoelk on here is from Saskatchewan, and is in process of building his firewood processor shed.  It is considered an ag building there, but he spoke with the building department and in order to accept his own milled timbers, they wanted it engineered/stamped and he got a letter from the engineer regarding his timber for the building department.  It's basically for the building department to cover their butts and make sure people are doing the right things and not something sketchy.  I know his talking with the engineer(at firetower) was a good experience and they helped him refine his design.  They also advised on his foundation.  He is doing piers in the ground with blocks on top.  Might want to speak with him?  This wood shed is a big shed as far as small sheds are concerned.  So it wouldn't hurt to have a proper foundation and floor and if you can get it engineered/stamped, it never hurts to prevent grief from building department or when you go to sell the place.

Your floor plan sounds pretty stout.  It's worth it to analyze what is can actually hold too.  I was working though that with Don in my recent post about my Second floor timber frame, and rjwoelk with regards to my floor loading.  You should also try to figure out what you plan to use for decking on top of the joists.  The weight of the joists and decking are your dead load. Live load is what you load on top of it.

[Hemlock121]

I called Development Services and apparently the Ontario Building code has changed and for storage buildings so permits are not required for building less than 160sf in my area.  Before I build, I will read more narratives from Will Beemer and others to ensure I build the building correctly.  Getting excited. 

Brad_bb, thank you for your insight.