Foundation Footers?

[Larry]

I built this 30' X 50'  floater 4 years ago...so far no problems with cracks in the concrete or drywall.  Put in #4 rebar 12" on center.




Year later built a 40' X 60' with conventional foundation 8" thick.  Footer was 8" X 16" and it was in a county with strict building codes.  Had to be 36" deep.  Cost and time was a lot more...even with our own labor, machines, and forms.  Went ahead and stuck the same amount of steel in it as the floater just to be safe.

Floaters are always cheaper and many times just as good as the conventional foundation for a shop.  Don't have any idea which would be appropriate for your area.  Think it would be time and money well spent to contact an engineer, architect, or experienced builder in your area and ask for there recommendation.

[Kirk_Allen]

I tried speaking with several contractors and they want $300 to come out and do an estimate.  I told them I am just looking for some advice right now and they said they get paid for there advice. 

I remember a skate boad park we built in Springfield back in the 80's.  The shop was octogan shape and the slab was a floater, but even that one had 48" depth on the parimiter.  Did that trench by hand >:(  Not this time ;D  Back hoe or no go!

[Larry]

Kirk, see if you can get a hold of the owner of your local concrete plant.  When I built the last floater I got a lot of free good advice.  Some of it saved money...he told me the fiberglass was mainly to control shrinkage cracks and not to use it if using rebar. ;D  He also pointed me in the direction of a few recent pours so I could see for myself how they were doing things.

[Kirk_Allen]

Thanks Larry.  Sounds like a great idea. 

I have a friend in Arkansas that used the fiberglass in his slab and they told him you dont need rebar with it.  Not sure if I am ready to except that peice of info just yet.  Thats just my skepticism comeing out but I do hear a lot of good things about it.

The dig should not be to bad.  I have access to a back hoe and I think I am going to shift my site to just south of where I cut, which has been farm field for 100 years.  I dont think I will run into any digging snafoos so that will help. 

If I have to make forms I assume you could do that out of 3/4 ply?   Might get pretty spendy just in the forms since I need to come up 4 feet.  Thats going to be a LOT of plywood.  I will have to check and see what contractors will charge to do that part.  They said if I hire them, the $300 for the estimate is applied to the bill. Thanks :(

Lots of home work to do and I appreciate any and all input.

[Buzz-sawyer]

I have been building these things since 1984 ...dont know if that qualifies me as a professional contractor in your area but here goes...$300 is not necissary........ ;)
Here is what I mentioned about the footing and re bar....(disregard the step form)

[Tom]

When I worked for my Uncle, years ago, he wouldn't have let a digging machine within a hundred yards of a footer.   He wanted it hand dug, straight, flat with clean sides and done with a shovel.  I learned from an expert that you pace yourself working on stuff like this.  It actually goes pretty quick.

If you have a sawmill and logs, why buy plywood for forms?  Boards work fine even if you have to use double thicknesses.  Nobody will see seams in a footer anyway.

[Buzz-sawyer]

Regarding the 48"
depth you guys have been throwing around,
for this lattitude that is way over kill.
Detroit has a 42" code requirement, here the standard is 36".........that adds up to a LOT of cost difference in concrete...any money saved should be put into steel,

concrete is like muscle , steel is the bones that allow it to be strong.
A monolithic slab, or floater uses the footing around its edge to stabilize it and keep it from creeping.
Tom
I dug several foundations by hand as a result of proximity to other buildings , and a good pace makes it easier than one woould think, almost fun.......welll, almost

Kurt I once built custom form out of 3/4 plywood and all thread, they were self supporting and could be picked up and placed as a unit in the trenches, they were latter used for flooring in the same house.
I made a instructional video as I did it.

[Kirk_Allen]

I guess I could use some Hackberry for forms.  Cant bring myself to use anything else.  You see, thats part of the problem with trying to be a woodworker and a Sawyer.  I look at every peice and can think of a project I could use it for.  I just need to accept the fact that a LOT of those projects will never get done.  Just dont have time. ;D

Is it best to pour the entire footings in one pour or do it in sections?  I assume one pour is the best but with just my wife and I doing the work not sure if thats a good idea. 

[Buzz-sawyer]

Oh, one last comment, you may want to cosider using foam under the slab in addition to your vapor barrier , it will help prevent the floor from sweating and keep you warmer.

[Kirk_Allen]

I was planning on using 2" blue foam board on the slap.  Still getting the numbers on the heat tubing for the floor.  I want to go that route as I know if I dont I will wish that I had. 

[Larry]

Concrete guys have told me the fiberglass can take the place of wire mesh...especially the wire mesh that nobody pulls up into the center of the slab.  No way can it take the place of rebar.  I did a little more investigation...little hard to finish...sometimes leaves a wooly surface...and turns slick.  JMO I would rather put money into rebar.

If you use plywood for foundation forms could you re-use it for sub-flooring or roof sheathing?  It would be lots of work using solid wood.  What about renting forms?  Or using blocks and core filling?  Just throwing out ideas...don't know if they are good or not.

I always put my footers in like Buzz showed.  Over the years ya pick up few tricks and stuff.  Found out when you overlap the rebar to meet most codes it has to be lapped something like 20 times the diameter if I remember right.

[Buzz-sawyer]

All I can say about fiber taking the place of structural steel, is that, respectfully , I think those fellas have wishful thinking.
I wonder if they ever demo concrete, which one breaks easier, which one is as strong as all get out, and stays in slab form when elevated and droppped....Steel baby!!

[Minnesota_boy]

Steel rusts, fiberglass doesn't.

[Buzz-sawyer]

Minn
I am just curious,
I dont get the comparison ???
I have never seen fiberglass rebar, or structural mesh (other than in fiberglass lay up)
Do you mean that rebar and mesh will degrade? I have never experienced that in above water concrete applications.It lacks oxygen in there, thus difficult to oxidize?I have broken too much steel reinforced concrete, or I should say tried to, It always has a patina of rust but hangs on for grim death.
The best I can figure the strength of fiber is similair to the horse hair put in plaster years ago , to give it some  amount of structural integrity...

[Minnesota_boy]

We have some extreme weather conditions up here, sothe comparison may not be valid, but lots of concrete bridge decks have had to be replaced because the rebar was rusting apart.  My only experience with the fiberglass in concrete was a floating slab in on building which hasn't cracked yet in 20 years. YMMV

[Tom_Averwater]

Around here  (southwest Ohio) for buildings with monolithic pours, they will use a 8'' trencher and trench down 30'' ,thats our code,around the perimeter of the building .Then they would form the slab/building  perimeter and pour the concrete. 2 to 3  #4 rebar were suspended in the trench. You could use your     2 x 6 or 2 x 8 wall studs as form boards and then use them in the wall. I would hold the building at least 12''  above the highest point of grade. Better to be a little high than low.         I  poured  a 48 x 30  slab on 18'' peirs with fiber mesh and it worked out great. Thats just my thoughts.  Tom

[Kirk_Allen]

OK, teach me:
Monolithic pour?
A slab on 18" peirs?

Any thoughts on whether to use 2x8 stud walls or 2x6?  If I can get away with 2x6 I will have MORE than enough lumber!

[tnlogger]

 kirk i was wondering how about a pole barn. you can get by with 8x8s 20' long on 8' centers 20 of them less the doors. 2x6 purlins every 4' and metal siding with bat insuation under the metal. you can still pour a slab around the posts. if you want a clear span build your own trusses out of 2x6s on a 5/12 pitch. with 2x4 purlins on edge for the metal roof. I helped build a 45x90 a few years ago for a woodworking shop. its still standing lol and a lot cheaper then stick built.
just thowing a thought out here 

[footer]

I agree that 48" or 42" is excessive in MO. also. But for some unknown reason, here in Nebraska, One county has 36" requirements and the next one over has 48".  Some places it is different from in town to out in the country.  I know for a fact that some winters, we have frost down more than 3 feet. A lot can depend on the soil type, and if there is snow on the ground through the Cold spells.   BTW, some places don't even require a frost footing if you insulate around the parimeter with styrophome, either streight down or out horizontally so that frost will not reach below the footing. That would be in a heated building though.

[Furby]

tnlogger is right about the pole building, but you have more costs involved in the finishing of the interior.
Most cases it's cheaper to do a pole building then stick frame, based on concrete costs alone, but it all comes down to what you want to do.

There are people around here that do pour a slab at grade and lay a course or two of blocks on top and then the stick framed walls. I helped on a 24'x36' and a 36'x40' built that way. Code does allow it in this area for "out buildings". Not to say that the best way to go though, because most people do go the extra effort and do the footings. Unless of course it is a pole building.

One thing I'd like to point out is the possible problems of laying a slab on farm field. It's possible that it may have too high amount of organic matter and may settle more and cause cracks.

Unless you are waaaaay out in the middle of no where, these guys should be giving free estimates if they want the work. I'd keep calling around. Don't ask for advice, just ask for an estimate and tell them you are considering do it this way, or maybe that way, ect. ;) Some I have talked to on the phone simply give me a sq. ft. price, others want to see things and give you a full write up on costs.

[Kirk_Allen]

Furby,
One advantage on the field is that it has been no till for twenty years.  Soil compaction is pretty good but I plan on taking off the good top soil anyway.  I have about 18" of top soil before I get to hard Clay.

I thought about pole building but this is something I want to last for my life time and with no maintenance.  I do plan on heating all of it some day but for now I will partition one end for my personal woodshop etc. 

I will try to make some more calls next week and see what I can come up with.  The problem is that we ARE way out in the middle of nowhwere.  Our town has 1 gas station, 1 stop sign, 1 bank, 3 Grain Elevators ;D

Our closest big town is Terre Haute, IN and that is 30 miles away. 

[Furby]

But still $300 bucks for an estimate ???
I'm in the wrong line of work then!  : : :

Sounds like ya got the soil thing figured out. ;)

[Minnesota_boy]

Kirk,
You have it all wrong.  Removing that 18" of topsoil is going to be alot of work, and then you need some kind of fill or your floor will be below the ground level and water will run in any time it rains or you have snow melt.  Move up here.  You will only have about 6" of "topsoil" and gravel under it.  Gravel makes a better soil to put under your building anyway.  Also, we have no building codes to have to follow, except for wells and septic seperation and electrical.  We don't need them, nature will tell you if you have built wrong by collapsing your building. 
My garage has a foot wide footer under the walls and 4" of floor with no rebar anywhere.  Nowhere near below frost lone, but with the gravel underneath, the ground doesn't hump with freezing, so my footers are sufficient.  The floor ended up with one crack after nearly 25 years of service.

[tnlogger]

 furby what we do is lathe the ind side walls and ceilings with 4/4 and use usb board or roofing metal. on the wood shop he got cover sheets for the place he bought his metal.
i think kevin paid 15cents a foot for scatched cover sheets 1.50 for a 3'x10' sheet.
then all he did was spray paint the whole thing white on the walls and ceiling.

[Kirk_Allen]

Since I have the option of 2x6 or 2x8 what would you go with?  I need to cut this stuff over the next few weeks but dont want to overkill this to much. 

16" or 24" centers- Pros and cons?