Moving the house was not enough so we moved a 40 by 30 metal truss metal siding bld from my father in laws farm to the new home site. Guy moved it in a day and half without dis-assembly. Older bld. with a very tall roof but it is insulated. I did the block foundation but not the floor. Now I am preparing for the floor I need some advice. Packed the red clay inside the blocks and the plan was for 4" of gravel and 4-5 inches of concrete. Should I do rebar or wire mesh or fiber or a combination of some kind? Additional info: I used 12" blocks for the foundation with rebar and poured blocks every 44". I plan on installing the pex pipe for radiant floor heat, materials arrived today. General shop use planned, cars, truck, tractor, storage. I plan on pouring a couple of spots deeper for a future lift.
Mine has fiber and some rebar, and it still cracked. I think that's what concrete was designed to do! ou:
The 3 rules of concrete: it gets hard, nobody is going to steal it and it's going to crack! :laugh: When I redid my auto shop floor, we used 5-1/2" of 4000lb fiber-mesh concrete, under the lifts and all. Most lift companies require only 4"-5" for a 10K lb lift. We didn't use ANY gravel (!) and poured right on the very compacted sand-based soil (actually on top of the foil/bubble insulation). We did radiant floor heat and epoxy, and have had zero issues. It hasn't cracked yet in 2 years (maybe in the control joints?). One thing with Pex - you probably have eliminated any rebar or wire mesh, so fibermesh would be the way to go. I was very skeptical at the way the contractor did it for us. So far so good!
IMHO Rebar can't be beat,literally.Wire does good if it is held in place during the pour.I say rebar is best from my experience in busting concrete up.The fiber stuff breaks pretty easy,wire mess harder,especially if done properly,but with rebar in there its a pain to beat the stuff out.Usually requires cutting the rebar.A real fun job:rant:
I would pour it at 5" thick and put 3/8 rebar in it. I would put it 2' to 3' squares. Compact the base good.You can tool or saw in your control joints. The squares created by the control joints should not excede 10' x 10'. You will want to smooth trowel the floor for your final finish. I perfer to not use fibermesh when I trowel the finish smooth because it leaves a fuzzy look to the smooth finish.If you are going to heat the floor you will need to put your base down and compact it very good,then install sheets of insulation proberly 1" thick then your plumbing then your rebar and tie it at every joint. Concrete will crack that is gauranteed,However it should crack in the control joint and the rebar will keep it from pulling apart or shifting up and down.Use a concrete mix no less then 4000 psi. And depending on the weather you can add chloride for set up pourposes.Never mind the weather your in the Carolinas! Lucky Stiff!!
PS - if you ask 5 contractors on how to do it, you will get 10 different ways... Be prepared. Very frustrating on how to pick out a right way!
Torqued your correct about the 10 different ways!(LOL) I do this kind of work and I have had great success with the method I layed out above.You can do more and I know you can do less. Its all up to you.
x2 Imop i like fibermesh and when it's troweld hard the little fuzz will wear off in time and its realy not that noticable Im a union cement mason for 25 years.Good luck
I believe you should use rebar for sure. I would go with a 4000lb mix and 5 inches if you ever want to put a lift in the garage. Many times the contractor will put in a 2x4 width which is short of the required 4" of cover needed for a 2 post lift. Make sure you cut control joints in the concrete as indicated above. The other thing I would consider if the garage is not insulated or heated is to put plastic under the concrete to prevent moisture from coming up from the ground. You will never have it rain in your building if you do that. It take a lot longer to cure becuase the moisture cannot escape out the bottom while drying but it is worth it in the end. Mark
My floor has about 5" of 2B gravel underneath, plastic sheeting, 2" of Dow Blueboard (for insulation), wire mesh and almost 1000' of PEX tubing. The concrete itself was poured at 5" thick and was epoxied a few months after the pour. Here we are three years later and not a crack to be found. I am waiting for it, though... it is inevitable.
We had to form and pour a chemical containment pad for a storage building about 10 years back. It was partially funded by the state of NC so there was a lot of B.S. In my opinion the rebar used was too large in diameter and also too much of it. I thought the pad was too thick too. It also had fiber added in the mix. BUT, when it was all done and years passed by it didn't have one crack in it. It's the only pad we have had poured in decades that didn't crack. I learned a lesson with it. It was in fact not B.S. but rather precautions that needed to be taken to make a good floor. Use rebar and plenty of it. Add fiber too. Make sure the trucks are on schedule and that their mix is not too dry.
I used the fiber additive on the large pads outside in front of the garage. No mesh and no rebar. That went against the norm and was a hard decison for me. I focused more on the base preparation. Zero cracks after 8 years and thats with PA winters freezing and thawing all the time. I run up to 16,000lb equipment over them. No matter what type of reinforcement you use, the key is how stable the base is. If you have expansive soil, it is more important to make sure there is sufficient drainage and grading around the site as well as a thicker base compacted by a vibratory machine.
We used rebar layed out in 12" Sq. pattern for the garage floor and they just formed and pored the parking apron in front using only fiber mix. The garage is perfect. the parking apron has cracked end it end. Shouldda insisted on rebar all the way.
Go down to your local farm supply and take a good , hard look at the ''goat fence'' panels... they come in handy lengths like 16 ft... and are much heavier gage than regular concrete mesh.... that way you dont have to use rebar except in places like door entrances and areas around a lift.... this stuff is the best concrete reinforcement that I have ever found... I used it on my car port and drive.... put a 80,000 lb. loaded concrete truck over it and it did not break.....
I have recently been reading a bit about reinforced concrete. The prevailing opinion is that rebar is the way to go, but it is a two-edged sword. If the rebar gets wet and begins to rust, it expands and cracks the concrete. A properly coated rebar solves this issue. Conclusion: Either use a properly coated rebar, or make damn sure that there is no way that the bar will contact a moisture source. Just my humble opinion.
Rebar for sure, an use rebar chairs or broken paving blocks (from landscape supplier) to hold the rebar up off the ground....wire mesh will just end up laying on the ground even if you try suspend it. We have cut many floors and always find the mesh on the ground! Your local building code will help determine the thickness depending on what you are driving on the concrete with...but a minimum will prob be 4" but i would go 5"? You may also want to add air or other additives, but i would definatly talk to the redi-mix concrete suppliers for some advice on what they normally supply to guys building shops. I would count on the concrete cracking so you should scribe or cut the concrete with a gas powered saw with a 14 or 16" disc from the 4 corners into the center of the shop. This will give a controlled place for the concrete to crack and you can add a flexible grout in the cuts so water can't penetrate the cut lines if the concrete ends up cracking in the grooves you cut. Cheers Gord
I was planning on putting the pex on top of the rebar. Has anyone had any experience with this? The stone will be 4-5 inches packed by mini excavator. The dirt was packed by mechanical tamper but the soil was not tested.
It proberly does not matter what you put down first the tubing or the rebar.You can suspend the rebar with chairs and rest the tubes on top of it. After your gravel is graded i would tamp it with a walk behind compactor,not just the excavator.I also would tool my joints while the concrete is being finished,if you go too deep with the saw while cutting the joints in after its cured, you run the risk of hitting your plumbing.And again speak with the plumbing people as to the order in which you put your tubes and reinforcing steel.I'm not sure it relly matters.
My garage currently has infloor heat, approx 6" slab, he-pex attached to rebar. I'm a bit foggy on the base but I'm pretty sure it was approx 4 inches of gravel topped with sand/crushers dust - compacted with a tamper on each layer, probably around 5-6" total base. Make sure you use an oxygen barrier pex piping such as 'he-pex' to avoid corrosion/rusting to any ferrous components you may be using in the system. My brother is a mechanical engineer who designed and built the garage. On a side note, I was thinking of putting a lift in my garage, until the thought of having to anchor the posts crossed my mind... wouldn't want to take the chance of hitting a pipe after all this money has been invested!
