JLP Blacksmith Teaching Center.

[Fowllife]

That big of slab is not something you want to just jump into and try for the first time, unless your only pouring part of the building. If I were pouring the whole 40x60 I would want 5-6 experienced guys, or 3-4 really good guys. If you doors are not at least 14' high you would need more since the concrete truck would not be able to get in and you'll need someone on a power buggy. 

The base is the most important part of your slab. Proper slab design takes into consideration many different factors. "Here" we usually don't put a vapor barrier under the slab, and we never use sand. The only time we use a vapor barrier is in office building that get floor finished, non of the warehouses or factories we do receive a VB. The reason why is it increases the slab curling (especially at control joints) because it promotes uneven curing of the slab. Typically we use 6-8" of 304's (3/4"-fines) with 2-4" of 57's (washed 3/4") on top. 

Your saw cut pattern for you control joints will depend on your slab thickness. There is a ratio for thickness and maximum spacing, along with a length/width ratio. Generally 12'x12' is about the maximum spacing, ideally with a soft cut or early entry saw as soon as possible and not produce any raveling of the joint. Also make sure you spray a good coat of curing/cure & seal on as soon as it's finished. Personally I hate a burned in finish as I think they are too slick. Even though it's a little harder to clean I like a little more texture to the finish so your not falling on your face with wet shoes.

As for the rebar, not enough info to give you any advice. Whatever you do will more then likely just be for differential shrinkage cracking and not a true reinforced slab. #4 rebar @ 24' o.c. each way will do that, as will welded wire mesh at mid slab. Also, make sure you use expansion joint at the perimeter against your poured wall, ideally 1/2" thick and the depth of your slab.

I would recommend hiring this part out. Any decent professional will know all of this and will know of any slight deviations that work better in your area. It can be done and look good, and it can also be messed up easily. If you hire it out and your talking to a contractor and mention the ACI (American Concrete Institute) and they don't know what that is call somebody else.....

[Fowllife]

To expand on what I said above. I get the wanting to do it yourself and saving some money. IF I were to do something like this myself here is how I would do it.

I would cut the building into 1/3's lengthwise and do 3 different pours. Do both of the sides first and then come in and fill the center. This is assuming you can get a truck into the building (concrete trucks are 12'-6" high.) If you did it this way you may be able to do it with 3 people, but it would be back breaking work. Mag float and set your concrete to height at the expansion on the exterior wall, and at you form. The fill the center as you run the screed board across the areas you just set to grade with the mag float while someone pulls the excess concrete away from you with a come a long. Do this the whole length of the building 3-4' at a time. After you get a few feet in the 3rd person can drop back and start to run the bull float, and steel trowel the edges. This is way easier with front discharge trucks, which you may not have available on the east coast.

If you wanted to try to work across the entire width of the building you could set grade pins to pour to in a 12'x12' grid or so. You need to be on the ball a lot more this way and it's way easier to mess up your grade. Essentially it's the same as the other way, pour a puddle of mud around your grade pin and set the height with your mag float and hammer the pin below the surface. Do this to all 4 pins making a square and then fill in between and screed across. It's easy for the edge of the screed board to dig in some and lose your grade.

If you haven't run a screed board at all (sorry if you have) I find it easier to do a couple big pulls back to get the grade close, and then a final pass or two pulling back with side to side motion. The side to side motion helps work the stones down and level the cream out. Renting a power screed would also be a good idea if there are any locally. I have never used one because I can usually round up the manpower needed, or it's a smaller pour.

Mind you, a 12-14' screed board is a load for an amateur and a rookie on the com a long makes it worse. You will also want to make sure you dowel all 3 slabs together with either smooth dowels or diamond dowels at 18-24" o.c.

If you can't get a truck in you would need an extra person to run the power buggy to bring the concrete into the building. Having a grid of rebar also makes it problematic getting the concrete in the building either way. That's why most guys will use mesh instead, or use a pump truck if they have a grid of rebar.

It may take all night to cure in these cool temperatures, but do NOT let them talk you into using an accelerator. The last thing you want is the concrete to start to get away from you because it's taking longer then you thought to get it laid.

As far as tools, you would need a laser lever, mag float, bull float & handles, steel trowels, concrete saw, screed board (aluminum ones are nice and not to $$) trowel machine, sprayer for the curing, and possibly a power buggy. For materials you will need form pins, forms, curing, and you might want to put plastic up so you don't splash mud on your white liner.

I would line up all of the equipment I needed and get it rented for a whole week. Get everything formed and ready for the first pour Monday morning. Set it up where you pour 1/3 Monday, the other 1/3 Weds. and the last third Friday. Modify the schedule as site & body condition dictate. 10-15 yards a day should be that hard on you as long as it's not a fight every day to get it down. After the first day you'll have a real good idea of how to schedule the rest. No way would I try the 30-45 yards the first day unless I had a GREAT crew lined up, which would probably need to be a Saturday as they would all work full time pouring concrete.

[Branding Iron]

Fowllife - I was thinking thirds as well. What are those metal Chanel strips on the inside edge of the forms to allow bending rebar out to connect to next slab and give a locking channel called? Seems like they could be useful in a scenario like this.  Vibrascreed could be your new best friend - try one out sometime!

 

[jlpservicesinc]

Fowlife,  Thanks for all the input.  It's spendid info and shows me at this point it might not be in the cards if I want it done now. 

with this. Lets move onto a few other questions: 

We have a high water table so going to use a 10mil barrier.  The floor finish is undecided whether epoxy or paint or urethane. 

 I was going to use standoffs that don't need to have the rebar tied together as they themselves are supposed to act as ties. 

The front section I was going to run the rebar out the foundation under the front roof to tie in the ramp to the main building???? 

The floor will be 5" thick and 3500psi cement. 

[Fowllife]

Branding Iron - I personally don't pour a whole lot of concrete anymore, but I'm sure your right on the vibrascreed. We have a couple at work I just haven't ever used one. Most of our concrete placement is sub'd out and placed with a laser screed. I'm not sure what kind of form you are revering to, but on that note construction joints should not really be tied together with rebar. Smooth dowels (one side grease ideally) should be used so the slabs can shrink as they cure and not produce and extra stress at the joint from the rebar not letting it slide.

Jennifer - Typically we only use a 10 mil VB in office building or a medical setting 6 mil is what we use the vast majority of the time if we put one in. I hear a lot of people mention a high water table, but the only time I ever see any additional requirements from a soils engineer is when we are building on wetland/swamps. Remember also if you use a VB all seams and penetration need to be taped. I know I have mentioned before that I am not a fan of anything below slab, but a lot of extra caution needs to be taken with anything below slab if your water table is truly that high. The possibility of an epoxy floor would have more of an impact to me then water table. Make sure you know the epoxy manufacturers recommendations before you pour. Most will require a VB of some kind. Most will need to shot blast before installing and some are real picky on curing chemicals. There are quite a few that require a water cure.

There are a lot of different types of chairs or stands for rebar/mesh support. If your going to hire it out I would leave it up to the contractor what they use. If they lay much concrete they have a preference and buy that type of stuff in bulk for hopefully a better price then you can. Commercially we almost always use mesh instead of rebar for floor slabs. As I said earlier, rebar at that wide of a spacing is only there to help with shrinkage cracking, not for reinforcing. Mesh does that same thing and is way easier to to install, which is why we almost always use it. If the contractor prefers to use mesh I would not rule it out. Some people may tell me I'm wrong on this, but I would like to see the proof. From what our engineers say there is no engineering data to back that up, until you get to a rebar size and spacing that qualifies as an actual reinforced slab. The same thing goes for a sand base under the slab. I sat through a ACI seminar a few years ago where the presenter discussed multiple case studies where a sand base caused problems with excessive curling and other slab issues.

I'm not quite sure what sure what you are talking about for tying the front slab into the building. Can you draw me a sketch? Tying your foundation wall to your exterior slab is a good thing. A layer of rigid insulation (blue board) over a washed stone base can go a long way to reduce frost heave. Maybe some east coast guys can correct me, but HERE you always try to a washed stone base under a slab, and never sand.

I personally like a 5" slab. In a lot of light application where 4" doesn't quite seem like enough but 6" seem like overkill it makes sense to me.

[jlpservicesinc]

So, the guy who is going to do the floor came by today and we strategized on what I need to pick up. 

We are in agreement with VB, slab to wall insulation (1/2" sandwiched foam).  and 

I was looking at using 4 Gauge feedlot fencing for the metal mesh.  It's 50" X 16ft long.  Its heavier than the metal stuff sold in rolls and goes for about 25.00 per sheet/section.   

I figure 33 would be about the right number..  if pulled so they overlap I would stick 10 across the long ways to cover the 40ft.. 

Then 3 rows to get the 60ft. 

 

Product Details

Protect and contain your livestock with this 0059-7 Max 50 Feedlot 10-Line Cattle Fence Panel. The feedlot panel is perfect for keeping cattle, pigs, goats, and other livestock or animals fenced in. The feedlot panel fence is lightweight and flexible, so it is easy to maneuver. With one piece welded steel construction, this panel is extremely sturdy and sag resistant, making it the perfect low-maintenance, high-quality feedlot panel.

• Feedlot panel won't break down or collapse when cattle, pigs, sheep or other large livestock run into or rub against it
• Constructed of 4 gauge wire
• Graduated 8 in. vertical x 4 in. horizontal to 8 in. vertical x 6 in. horizontal mesh
• Welded one-piece steel construction helps the feedlot panel fence last for years
• Virtually maintenance free
• Sag resistant
• Easy to erect with no stretching
• Not all panels available in all stores
  
  
  What do you guys think of this as an idea.. Much heavier than the wire spool stuff? 

[Frosty]

Don't cut corners on this Jennifer, this is prime, "Penny wise dollar foolish," territory. 

I know you want to get this over with so you can get on with the Learning Center but please bear in mind what I tell new guys all the time. The only thing rushing is guaranteed to do is make your mistakes permanent more quickly. Trying to save $1k now could easilly cost 10s of thousands to repair or cope with later and this building is going to last a LONG time. Yes?

Frosty The Lucky.

[jlpservicesinc]

Frosty,  I won't be doing the floor so the costs will be what they are. 

As for materials to go in it.   the stock fencing is heavier than the other rolled product that is 1/3rd the cost. 

I would think heavier is better and everyone I have talked to so far either did not use Vapor barrier or rebar.. 

So, the added expense of the VP and heavier mesh I think would be a good thing. 

The vapor barrier will be needed for when the floor gets coated. 

Something I thought was really interesting is the use of heat to speed up the cure time.  

His concern being it will take to long to setup???? 

We aren't having a frost here and inside the shop it hasn't gone below freezing even with open sides. 

So, is there a danger of the concrete not setting at all?  I've never heard of such a thing.. 

 

Got that little section of insulation in and the membrane trimmed out. 

I then went to install the insulation hangers on the other wall only to find the hangers won't work because there are no place to attach them. LOL..  What the..    There is literally no where to attach the hangers because the main beam has a gap between it and the metal of about 8" and no way to just slip them in.   

another figure it out project. 

[jlpservicesinc]

4 guage is nearly a 1/4" thick.

 

[Fowllife]

Frosty is trying to say he thinks using mesh is cutting corners. Unless your going to get a pump truck though it's hard to pull off rebar and set it placed right. Granted mesh also has the same placement issue. Regardless of the reinforcing type it needs to be in the middle of the slab. Your installation crew should have at least one person assigned to pulling the mesh up to mid slab as it's being poured.

I would not used galvanized stock panels for reinforcing. Whoever is pouring should have access to mesh in sheets, 8' wide x 16-20' long. The two most common sizes in my area at least are 6x6 10/10 and 6x6 6/6. the first two number are the spacing (6"x6") and the second two numbers are the wire size (10ga and 6ga) If the supplier is progressive they may be using the newer metric designation of W1.4 and W2.9 respectively. If you can't find any sheets though I would use stock panels before I would use rolls.

When they were talking about using heat they could have been talking about actual heat, or an accelerator. An accelerator essentially heat up the concrete and help drive our the moisture sooner which speeds the curing  process. It's not a matter of it not setting as much as the crew doesn't want to be there until 2am waiting for it to set enough to finish. Unless someone screwed up bad at the match plant it will all set eventually. They should know what additives they want to use depending on pour size and what their crew can handle. If you are super worried just request a copy of the tickets along with any additives used and make sure they are clear if they use accelerators and you are not happy with the finish they will need to fix it, either by grinding or replacement.

I have found a lot of people way overthink concrete floor pours in terms of thickness and reinforcement. Does a lot of the "extra" stuff help, sure, but it's not needed 98% of the time. When it is it's usually because they didn't do a good job with the base. The base is more important then what's in the slab.

I should say that all of my knowledge on this subject comes from the company I work for. We do several hundred job a year and have poured millions of square feet of floors over they last 70 years. We have fine tuned what does and doesn't work and balanced that with what is cost effective. I'm not just a guy who has poured my own shop floor and that's it.

Proper base and proper placement are the two most important things, if you need to rely on reinforcement you missed the mark on one of those two.....or you have really crappy soils and you should have built somewhere else.

[jlpservicesinc]

Fowlife.  

I understand and thanks for the clarification.   

Not really great at reading between lines..  LOL. 

This particular project has been one of "Surrender"..   I have had to take a back seat to which ever way the winds blow vs Driven to perfection. 

It's a long story so won't bore you.. 

None of it is perfect and from the get go it's just been one thing after the other. 

So, If the building lasts 30 years that is 3000.00 a year in ownership not including heat, taxes, etc, etc, Just building it and cost of ownership.  

I try to do things as right as possible so installing the rebar would be ideal but it's funny when I look at examples because they show even less of the rebar then I would of installed. 


Here is todays haul: 

Tomorrow I have a buddy coming to start the prep with leveling the aggregate and we will start installing the liner. 

 

[Frosty]

17 hours ago, Fowllife said:

Frosty is trying to say he thinks using mesh is cutting corners.

No I wasn't mesh is fine. I certainly wouldn't use ranch / stock panels though, there is mesh designed for concrete.  I don't work concrete, my skin is too sensitive it burns me if I let it stay long. Did a lot of testing in the materials lab but that's completely different. 

I had the slab in my shop laid by professionals, though I did the grade work myself. That IS something I know.

I was cautioning Jennifer about trying to do too much of the job herself to save money. Some things aren't worth doing yourself, I've been there done that. I accept full responsibility for the things I screwed up building the house and am not doing that again. 

Ditto on the additives, the slab will set and cure no problem. Concrete gets poured here in sub zero temps though nobody wants to it CAN be done. 

Frosty The Lucky.

[jlpservicesinc]

my buddy came over at 9:30am and we got the insulation into storage position and then started to clean up all the leaves and such..  Got the tarp moved outside into position for when the floor is poured to block the wind at the back door. 

We then put the liner into it's roll out position. 

Andrew had to get going, so once he left.. 

I then drove the manlift back and forth looking for any settling of the materials in the tire tracks.. 

After this I called it quits.. I'm feeling a little tired today so ended about 230pm. 
 

 

[jlpservicesinc]

Wow, so it's been a few days with no updates. 

Got the base line insulation installed.  Got nearly all 11 gozintas installed.. 2 left and then I need to make 1 more. 

they are on a short 12ft pattern with, 4ft, 8ft and 12ft.  I left the grid just a tad short so a 4or 8 or 12ft bar will have about 1" sticking out each end..  this means if the tubes are up for railings and such there will be a little clearance for weldng and such. 

Got the in floor fume removal pipe in and the whole floor/ leveled and 1 of the outside boards up to retain the cement at the door opening. 


I had to make a few steel stakes since wooden ones won't penetrate the material on the floor. 

Tomorrows plan is to install the last Gozintas and check level one more time.. 

then Membrane. 
 

[jlpservicesinc]

I installed all but 1 of the Gozintas.  Which I need to make. 

9 horses today and then multi hours in the shop..  

The gozinta area is now level and everything in the middle and nearly all the floor area is level.. 

The floor will be 5 to 6" thick of 4000psi concrete.  the 6" thickness will be where the car lift goes and also the power hammer.   I have the area under the work stations about 5.5". 

After some considerations I might not put in a rear door but instead frame it out.  this will add and area for a cupola. 

Not sure yet will have to see. 

the membrane will go in tomorrow as will the twin ibeams for the welding grounds. 

[jlpservicesinc]

And today was another crazy day under the roof. 

One more day of prep.. Monday is the big day. 

I extended the evac line and added 3 more ports. 

I also got the weld plate done and ready for install..  

[Daswulf]

Moving right along. What size are the gozintas? 

Wow, you'll be up and running in no time now. 

[jlpservicesinc]

I can't wait.. the floor going in will mean I can take a slight break or at least slow down some. 

The gozintas  are 4OD 1/8" wall x 18". 

I'm so excited..  

[arkie]

Jennifer, pardon my ignorance, but (1) what are "gozintas" and (2) what are the square black things and round PVC things protruding from the ground floor for?  Looking great so far...you have done a tremendous amount of work on the school building.

[jlpservicesinc]

Arkie,  Goes into  =  Gozintas..      They are used for many things..  they can be used to hold uprights when building gates or stair railings  by putting in smaller (3" or 3.5" square or round tubing or pipe) and then wedging them into the sockets. 

they can also be used for pulling frames an such with tight fitting tubes or solid stock using 1 on one side and 1 on the other. 

These are spaced  4, 8, 12ft..  Which is slightly undersized so like 46, 94 etc, etc. .This way a full 4ft,  8ft or 12ft distance can be clamped by the end of the bar can be accessed for welding.. 

The PVC looking things are for the dust and weld fume extraction pipes..  These will be cast into the floor to be flush and when in use a hose will be attached and then laid by the welding to suck the smoke and fumes out. 

Not really designed for a vacuum system for larger items I did mimimize bends and installed all joints as smooth as possible.  Of I install a larger enough vacuum/extraction system I might be able to use it for vacuuming as well. 

All the gozintas and the PVC will be buried in the Cement and the floor will be flush or smooth. 

Thanks.. I'm starting to see daylight and getting excited.  It means I won't have to work 12 hours a day ontop of my normal work. 

[arkie]

OK, thanks for the explanations.  I generally knew what a gozinta was, but didn't know what you would be using one for in the floor (I guess I didn't phrase my question correctly).  I assume with the extraction tubes, you might be teaching some welding along with smithing.

[Frosty]

A word of advice regarding the air extraction tubes Jennifer. Compact the dickens out of the material on top of them. I ran the plate compacter over mine till I was worried I'd crush them. A couple still floated when the concrete was poured. They didn't come to the surface but lifted a couple of my gozintas above flush by almost 1/8"

Had I realized it was a possibility I would've filled them with water along with compacting them till the machine was bouncing too.

I THINK running the paddles over the gozintas and covers was just enough joggling to loosen them. 

Frosty The Lucky. 

[jlpservicesinc]

So, just finished up for the day. 

The guy at the mason supply shorted me 8 panels.  So tomorrow morning at the crack of dawn I gotta rush off to get 8 more to fit them.. ARRRRRRHHHH,.,.  

The last few days I have been really, really pushing it to get all the things done and adding the extra length of fume extraction and the extra gozintas really cut back on extra time so to speak. 

Anyhow,  I am starting to think the "Blacksmith trailer" build was in prep for this..  To actaully make me accountable for my time and dedication. 


Today started at 845am and just finished now at 10:56pm. 


Dick L. was so kind enough to come out and help again today on a Sunday no less.. He left about 630pm and he was very tolerant of my crabbiness.. LOL.. What a great guy..  Hugs to you, sir..  

I'm burning the candle up pretty quickly and tired is normal right now.  

I have 1 more day of the big push..  Floor is scheduled for tomorrow..  I think it looks pretty good.. 

[George N. M.]

Jennifer:  It is really looking good and I am jealous.  I wouldn't have been willing or able to take on a project of that magnitude.

I would have demanded that the mason supply guy who shorted you deliver the 8 panels to your site.  It is his mistake, not yours and the remedy should be his.  Either that or he refunds a portion of the cost of the 8 panels.  I suggest the difference between his wholesale cost and your retail price.

Question:  Are you making any allowances in the floor for heavy machinery, e.g. power hammers, bases?  It may be fate or something but if you are not I will bet that within a year you will have the opportunity to acquire a 100 pound Little Giant for a reasonable amount and then have to deal with the issue of a base.  It is something related to either Murphy's Law or just the natural perversity/cussedness of human affairs. 

I wish, and I think I speak for many of us on IFI, that we lived closer (for me, it is around 2,000 miles) so that we could come and give whatever help we could.  That said, it has been fun to watch your progress.

Good luck and you can see the light at the end of the tunnel.

George

"By hammer and hand all arts do stand."

[anvil]

11 hours ago, George N. M. said:

give whatever help we could.

Me too