Maybe a little premature--- but the shop is on it's way

[Aaron Berk]

I got my blueprints in the mail today

I'm building a 16x24 shop on a skid foundation, with a stick framed roof and light attic storage
I've already sourced my skids from Craigslist, and have some 12ft 6x6's laid out in the back yard.

I'll be dropping off my material list at a few lumber suppliers in the next day or 2. And looking for the best deal.

I'd like to go with a tin roof and install a few clear panels to bring in some natural light. I'll be keeping the side windows to a minimum in an effort to increase interior work space. I was thinking about 10' walls with long narrow windows at the top. We'll see.

So I'm finally on my way to getting out of the garage!

And yes, I do own a camera, and there will be pics

[Erik France]

Sounds cool! Spacious even.

Not sure how your skid foundation is laid out, but you probably want to make sure the exterior perimeter walls are well supported. My shop is a little 10x12 shed on skids with a 5' wide storage hall added down one side. It wasn't designed for all the stuff I have crammed inside. I'm not sure when the previous homeowner built it, but I've had it for 11 yrs. Between some rot and bugs, not to mention the loads, I'm having some structural problems.

A couple of the walls were cantilevered over the skids, especially the back wall. Now some of the floor joists are crushing where they bear on the skids. I've added CMU blocks & bricks around the perimeter trying to get it somewhat level, and to help transfer the loads. I've got shelves around the complete perimeter taking advantage of the gambrel roof space, plus all of the wall mounted storage. There is quite a bit of weight bearing down around the exterior. Way too much for a cantilever.

Take a good look at yours now, as it is not pleasant messing with it later. Most of those outbuildings weren't designed for all the cast iron tools, lumber racks, benches etc.

[Aaron Berk]

Thanks for the incite (spelling?)

Over kill is my middle name, with that in mind. I'm still trying to go over kill even by my standards.

I'll have 14ft 6x6 skids going down the exterior walls (24' direction) and they will be half-lapped by about 2 ft. then cut 2 length, I think I'll cantilever a front porch just for fun.
The center will get 12' 4x6 skids sistered with 2x6's to equal 24' plus porch length.

I'll lay 3 piers made up of sets of pavers on a gravel base (3x3' sq and 12"deep?) for each skid section.

Then I'll use 2x6 joist on 12" centers.



And the board say????? yeah or neah?

[Don Bullock]

Congratulations Aaron! That's great news. Enjoy.

[Mike Cruz]

Congrats on the beginnings, Aaron! It will be a long process. It will probably take longer than you think. Will likely cost more by completion, too. But enjoy the ride. It IS a fun one.

[Van Huskey]

Congrats, guaranteed to be a long strange trip!

[Erik France]

The center will get 12' 4x6 skids sistered with 2x6's to equal 24' plus porch length.

I'll lay 3 piers made up of sets of pavers on a gravel base (3x3' sq and 12"deep?) for each skid section.

Then I'll use 2x6 joist on 12" centers.

And the board say????? yeah or neah?

Sounds like you've got a pretty good plan. The way I understand it; your 2x6 joists will have roughly an 8' span. I did some quick calcs and they will handle some decent loading without a lot of deflection for most species of wood. Not exactly what I would call overkill, but it's more substantial than a normal residential floor. I would double or triple the joists under the end walls (16' length walls).

I'm not real sure about the skids though, especially the middle one if it's just a 4x6. With the block piers they will be acting as beams. I was getting some pretty high deflections and some failures with the calculators and loadings I was using. You mentioned sistered with 2x6s, but I'm not exactly sure what you meant.

At work, I usually leave stuff like that for the engineers. I just did some quick & dirty calcs to satisfy my own curiosity. I think it will work for some light loading, but It'll probably be a little springy.

[Aaron Berk]

Well 2 of my boys and I went out and got a ton and a half of gravel today. They had a blast watching the loader dump it's bucket into my F250. This was the first time I've loaded up my powerstroke, it hauled like a champ.

I got home pretty late and was only able excavate 1 area where I'm putting a retaining wall by the back left corner of the shop. I don't trust the current set up of 4x4 posts and 1x6's as the retaining wall It was barely enough to hold back the current load. Having a shop corner by that wall worried me. So I dug down 3' to the base of the current wall and built it back up with 4x6's laid on the flat and then drove 5' pcs of 5/8 rebar down through the bottom 3 courses of timbers. back filled with gravel.

I'll start work on the 9 pier pads tomorrow, I may just end up pouring the pads versus 6" gravel base and concrete block. Not sure yet, I'll see what I think when I lay the gravel, I can always put a form on top of the gravel and pour a pad anyway.

ERIK---
Good call on the triple joists for the end walls, I think I'll do that.
My 2x6 joist should be less than 8ft span and the on line calc I used said I could get over 90 psf live load and at least 20 psf dead http://www.awc.org/calculators/span/...al+Span#answer

And as an over kill, I've even thought about a second layer of ply on the floor. I value your input, thanks for the response


I tried taking pics of my layout tonight but it was to dark and the shots look horrendous. I'll have pics up tomorrow.

[Aaron Berk]

I have 2 options with my floor joists that I can think of.

I want 2x6 joist. Reason being, is over all building height.

Option 1:
So with my 2x6 joist I can buy 16 footers and run them from one perimeter skid, over the middle skid, and then to the other perimeter skid. This would make my floor height a total of pier height, plus 6" skid, plus 6" joist, plus sub-floor.

Option 2:
Buy 2x6x8's and hang em on joist hangers between the skids. This would give me a MUCH lower floor, allowing me to raise my ceiling height, and eliminate the need for rim joist.

I think I like option 2 the best, but I don't think it's going to save any money. It will cut my joist span down to almost exactly 7.3 inches which with a 12 on center spacing is a very solid floor. I think I could also reduce the amount of necessary blocking as well.

The biggest detail would be getting all 3 skids in perfect plane with each other. A test of true craftsmanship

Anyone see some major issues with this?

[Erik France]

You're welcome. A lot of this I've been considering as fixes to mine and plans for something bigger.

I think your joists are OK, especially being at least No2 Southern Pine and the 12" spacing. It's the skids (beams really) that I'm not sure about, especially the middle one. If it's just a 4x6, I think it's inadequate. Attached is a quick sketch showing the loading on the skids. I was using a rough 8'x8' on the loading and this beam calculator yesterday. I can't find the online one I used to use. I plugged some info into another one, but I didn't mess with it much.

Hanging the joists will save you 5 1/2" in height, but that'll mean a lot of hangers (108 of 'em) and cutting each and every joist (54 of 'em at least). I'd go with the continuous 2x6 myself.

I don't think adding a second layer of decking would gain you much, especially with the 12" joist spacing. Going with 1 1/8" instead of a layer of 3/4" would help some. If you have some heavy stuff with point loads you might consider the thicker decking; like a cabinet saw on a mobile base or a lumber rack on casters.

I have been kicking around doing removable floor deck portions so I could get underneath to run DC ducting and floor plugs. Maybe just 4x4 sections might work for me.

[Aaron Berk]

Does it make any difference that my beams are true dimension rough cut?

I could nail/bolt 2x6's to either side of my center beam making it a "7x6"

I'm not a fan of point loads, my cabinet saw sits still, and lumber rack will be wall mounted

I was messing with the foundation today and got to thinking that yeah, continuous 2x6 joist are the way to go.

These pictures show my timber and pier layout (not permanent) just setting them up to see what I'm looking at, and then a shot of my labor crew putting in a small retaining wall.

[Erik France]

Yes, rough cut will make a difference. The bigger the section of the wood the more it can carry.

Some of these calcs are over my head. I was hoping a real engineer might weigh in. I am unsure how to design for live loads. You're basically doing a pier & beam foundation. When I hear skids, I usually see them as bearing across the whole length of the member. I also just realized that I was just looking at floor loads, and I didn't even consider the loads from the roof and walls on those outside 6x6s, (much less shelving, cabinets, etc.) It's been a long while since I had to do any real structural design. My statics classes were a couple decades ago. Looking at some of these formulas today reminded me of how much I didn't like them.

On that shot of your foundation mock up, make sure at least 2" or so of your pier is below the full section of your outside 6x6s. Otherwise, your beam would be more like a 3x6 if just the half lapped section is bearing on the pier.

[Aaron Berk]

Good call Erik, I'll adjust the center piers on those 6x's I'm also going to through bolt them with 5/8" hardware.

Yeah it's a hybrid skid thing going on here