Concrete Reinforcement Question!

[Model A Fan]

I've gotten to the point where I need to buy mesh for my future pad. I'm shopping at Home Depot and they have two types. A roll that is 5' tall and 150' long for $105 and the panels that are 3'x7' for $7.20/each.

I'm going to need enough to cover my 18'x25' pad. This means 19 panels ($150 after tax) or I can use the roll, but have 40' left over or so and that would be $115.

Is one better than the other? Is it worth the extra $35 for the mesh panels to avoid the need to measure and cut the roll and then try to get it to lay flat so I can tie it down? I'm leaning to the panels even though it's more expensive per square foot.

Advice is greatly appreciated.

 

[DougWil]

My advise. Don't use mesh, use rebar.
#4 @ 16" or 18" OC each way. Your feet can step through it.

Rolled mesh isn't flat, all mesh usually gets stepped and ends up where it shouldn't.
You didn't say what wire size and spacing of mesh, but it probably is less steel area than the rebar I suggested.

If you have your heart set on mesh, go to a real rebar/mesh supplier and you can buy sheets 7' wide x 20' long.
4 sheets and you are done with little waste.
^That is where you should be buying rebar, way cheaper than HD and in 20ft lengths.

 

[drivesitfar]

Model A: I always have used REBAR or scrap steel on my sidewalks and most of the flat surfaces I've poured. I had a couple young kids to a pad for me 30 years ago with mesh though and even though my yard fell into my neighbor's house (his fault) 1/2 the pad sat suspended and held up and I think it was only 4 inches thick. if I recall correctly they used the roll and I probably would if I didn't have any rebar. I usually pick up rebar any time I see it laying around when i'm buying tools or STUFF so I usually have some. I need to use it on the new driveway i'm planning on pouring hopefully this year.

also if you do get rebar we use decent size rocks we find in the yard and toss in a bucket or the stores sell little plastic risers to keep it settling to the bottom.

good luck

 

[Model A Fan]

I was planning on the mesh because it is pretty convenient and readily available. I was going to break bricks and run wire around them to connect them to the mesh. I'm not aware of a source for large panels in my area. I have a limited ability to bring home stuff like that too.

Thanks for the info guys.

 

[matt_i]

Panels stay somewhat flat, the roll will play hell trying to keep it flat.

I second the recommendation to buy a truck of #4 rebar, a thin cutoff disk for your angle grinder, a bundle of 1000 prelooped wire ties and the spinny J-hook to tie them up. Bend with the receiver hitch on a pickup truck. Goes very fast.

Call up your local ready mix for all the supplies cheaper than HD. They might even deliver it.

 

[rlitman]

For anything more than a couple of sticks, rebar from a local steel supplier will be WAY cheaper than from HD. For a serious tomato cage project, I ordered a bunch of #3 rebar, had it delivered in 20' lengths and saved a bundle vs buying myself at HD.

As for a cutoff disc, yeah, you could do that, and it would work for a few cuts. I bought a set of HF's largest bolt cutters (42" IIRC) and modified them with a bracket so I could lay one handle on the ground and have it still stand up (to use it like a rebar cutter but much cheaper). They ran me around $35. I made a few thousand cuts, and they still look like new. I've also got a Portaband which is amazing on rebar, but the bolt cutters were cheaper than blades for this project.

 

[Leaflessshadetree]

The rolls of mesh are usually thinner wire than the sheets, but either can work. If I recall the reinforcement sheets I got from the concrete company (same place I bought the concrete) were 5'x10'.
Do not use broken (or any) bricks to support the mesh. They can create a weak spot in the pad.

 

[Evilunclegrimace]

When I poured the back half of my 26X36 pad I went to Tractor Supply and bought cattle feed lot panels and used that for my mesh. It is 4 gauge welded wire and will take being walked on with out bending like regular reinforcing wire.The panels come 50" x 16' and are $21.99 plus tax. If you watch they do go on sale from time to time

 

[Cyberbear]

Depending on what usage the slab will be put to, but these days with quality concrete being less than it used to be, I too would opt for the rebar. Mesh is best for sidewalks and low stress usage. Mesh won't prevent cracking but only holds the pieces together when it does. The real secret is lots of steel and 6 bag mix or better. Once down concrete never gets better, only worse, and it's something you live with forever. When looking at ugly cracks, no one ever talks about the few bucks they saved, just about the bad results from trying to save a few bucks. Also, use a sealer to retard moisture loss during the curing process.

 

[lakeroadster]

Model A Fan I think your choice of wire mesh is a good one for a properly designed residential slab that doesn't see high loads and that has a properly compacted sub-grade. The wire mesh 6" square pattern is better than re-bar spacing of 18" or 24".

Opinions vary, and this is just my opinion based on my "good luck" on the 4 previous buildings I have had at 3 previous homes.

In regard to your Wire Mesh questions: stay away from the rolls, buy Wire Mesh Mats.

There's a lot of engineering that goes into concrete welded wire mesh. Here's a link fall that engineering: Standard Practice for Structural Welded Wire Reinforcement.. lot's of good data here: http://files.engineering.com/getfil...c=212727627.1.1462365501037&__hsfp=2700961102

The concrete wire mesh at Home Depot and your local lumber yard is typically 10 gauge, the thinnest wire mesh mat available.

8' x 20' concrete wire mesh mats are available from companies like HD WhiteCap (they have stores in Washington) in various gauges, such as 10, 6 and 4 gauge.

Here are some more links for you:

6 x 6-W2.9 x W2.9 6 ga 8' x 20' Wire Mesh Mat http://www.whitecap.com/shop/p/6-x-6-w29-6-ga-8-x-20-wire-mesh-mat-4346666g820

6" x 6" W1.4 10 ga 8' x 20' Wire Mesh Mat http://www.whitecap.com/shop/p/6-x-6-w14-10-ga-8-x-20-wire-mesh-mat-4346610g820

To support the wire mesh mats use concrete dobies. These are square pieces of concrete with a wire in them that allows you to tie it to the mesh.

Here's a link to various dobies: http://www.whitecap.com/shop/wc/search?searchTerm=dobie

And this is the size I used. I picked them up at the local HD Whitecap for 0.28 cents a piece: http://www.whitecap.com/shop/p/dayton-superior-cwd-2-dobie-with-wire-123704

I'd caution you on the use of bricks. Ideally you want a product that the concrete will adhere to, and that wouldn't degrade over time and leave a void. Nothing is better than concrete for this application.

If you use 6 gauge concrete wire mesh, on concrete dobies spaced on 24" centers, it is a stiff enough assembly such that it stays where you want it.

Hope this helps. Good luck with your project.

As a side note:

I would recommend against the use cattle panels that Evilunclegrimace recommended above. Most of these panels have a non-uniform panel layout which creates non-uniform stresses in the concrete. Concrete wire mesh is made from high tensile strength steel specifically manufactured, welded and tested for it's intended purpose. Cattle panels are made for, well, cattle.​

 

[DougWil]

I was planning on the mesh because it is pretty convenient and readily available. I was going to break bricks and run wire around them to connect them to the mesh. I'm not aware of a source for large panels in my area. I have a limited ability to bring home stuff like that too.

Thanks for the info guys.

Mesh has to be overlapped.
With dinky 3x7 panels that is a lot of overlapping "waste".

 

[ms fowler]

For your use the mesh panels will be fine.
Never try to use rebar or mesh to compensate for poor subgrade.
Concrete WILL crack--it shrinks as it cures. Control the amount of water added when placing the concrete--keep it in the 4" -5" range, any wetter and the crack issues compound.

 

[lakeroadster]

Mesh has to be overlapped.
With dinky 3x7 panels that is a lot of overlapping "waste".

OP, Wire Mesh Lapping and Clearance:
"By over lapping the welded wire fabric at least one space at the ends and sides of the rolls , the effect of continuous, unbroken reinforcement is gained with no gaps where cracks might form. (Space refers to wire spacing; that is, 6X6-10/10 fabric would be overlapped about 6 inches at the ends and sides of rolls. Nest the overlaps for a snug fit.) Laps are wired together, 18" spacing, to assure continuity. As a general rule, allow 1-1/2 to 3inches of clearance between the fabric and the form work."

 

[Milton Shaw]

What ever you use, don't do like a neighbor did. He had the floor poured and then saw the roll of mesh leaning against his house. He was pissed to say the least. THe crew had walked by it with every wheelbarrow load.

 

[TAMPAGT07]

What ever you use, don't do like a neighbor did. He had the floor poured and then saw the roll of mesh leaning against his house. He was pissed to say the least. THe crew had walked by it with every wheelbarrow load.

It's a good habit to be there when a crew is pouring concrete.....

 

[DougWil]

OP, Wire Mesh Lapping and Clearance:
"By over lapping the welded wire fabric at least one space at the ends and sides of the rolls , the effect of continuous, unbroken reinforcement is gained with no gaps where cracks might form. (Space refers to wire spacing; that is, 6X6-10/10 fabric would be overlapped about 6 inches at the ends and sides of rolls. Nest the overlaps for a snug fit.) Laps are wired together, 18" spacing, to assure continuity. As a general rule, allow 1-1/2 to 3inches of clearance between the fabric and the form work."

Yes, and so with a 3'x7' sheet with 6" grid that only equals 2.5'x6.5' coverage per sheet.
Or 23% of that dinky sheet is wasted in overlap.

 

[DougWil]

What ever you use, don't do like a neighbor did. He had the floor poured and then saw the roll of mesh leaning against his house. He was pissed to say the least. THe crew had walked by it with every wheelbarrow load.

Oh, they would have walked all over it anyways shoving it to the bottom of the slab where it would have been near useless anyways.

 

[buening]

I too prefer rebar, for the exact reason as shown in the picture above. Welded wire fabric has closely spaced wires and is impossible to not walk on, which pushes the mesh down to the subgrade. Rebar is obviously a lot more work since you have to tie it and use properly spaced chairs. All depends on how much work you want to do. If you do go with fabric, use the sheets and not the roll type.

 

[lakeroadster]

Yes, and so with a 3'x7' sheet with 6" grid that only equals 2.5'x6.5' coverage per sheet.
Or 23% of that dinky sheet is wasted in overlap.

Exactly why someone posted links to the 8' x 20' sheets above.

 

[DougWil]

I too prefer rebar, for the exact reason as shown in the picture above. Welded wire fabric has closely spaced wires and is impossible to not walk on, which pushes the mesh down to the subgrade.

Sing it to me Brother!!!

Exactly why someone posted links to the 8' x 20' sheets above.

I resemble that, post #2.

 

[ozyborn]

My dad had came across a large pile of 1" road rebar he gave to me. When I poured my driveway. 12x25 and a 8x16 next to and in front of my garage I used that. With a 6" slab. Used the risers, tied everything together and sandblasted any corrosion off and primer coated before the pour. EVen my sidewalks I use rebar. Mesh? No thanks. not in any on my pours.