Fibermesh question - can you see/feel it?

[bas157]

Hello
I had a 12x20 slab poured for a shed and the quote says “…4" Thick 4,000 PSI reinforced with wire mesh (6" x 6" w2.9 x w2.9 and fiber mesh plain concrete) …”
I was under the impression that if you had fibermesh in the concrete, that you would be able to see all these tiny little ‘hairs’ on the surface. Can you also feel them?
I’ll have to take a better/closer look at mine, but I don’t recall seeing any hairs and I haven’t felt them either.
I’m wondering so if they didn’t include the fiber in the concrete I can say something to the company. Perhaps ask them to show me the paperwork from the concrete company (the company that delivered the concrete, not the people that did the slabwork).

Thanks
Bruce

 

[brownbagg]

yes you can them quite easily, without your glasses

 

[ConCretin]

"plain' concrete typically refers to concrete without steel reinforcment so there is a contradiction in the wording. Any chance the wording was either/or?

As long as you got the mesh and didn't pay for the fiber, you are good.

 

[csp]

It depends on what kind of fibermesh it is. The new stuff can't be seen sticking out of the top.

 

[bas157]

LLWillysfan - that wording was copied and pasted from the quote. I know the wire mesh is in there as I saw that, and I did pay for the fiber, at least when I told them what I wanted, I told them I wanted the fibermesh and wiremesh. I'll take a closer look at the slab and also at a little bit of the extra I let them dump along some trees that I'll throw out or something, figure that I can break up and see if there are any signs.
CSP - if you can't see if sticking out the top, how can you tell its there if you don't see them actually add it into the concrete when being mixed?

So if there is no fiber, what would you recommend, that I ask for some money back from them? If so, what does the fiber add to the cost? Not like I can ask them to come back and repour it or anything like that.

 

[ConCretin]

Even if you can't see the fiber sticking out of a steel troweled slab it will definately be visible in any chunks laying around.

While I like the idea of both fiber (to control early plastic shrinkage cracking) and wire (to control thermal or subgrade caused cracks) it is not typical to use both. If you were going to get just one, the wire mesh is the better of the two.

If you paid for fiber, you should ask for a credit. Up here it goes for about $7.00 or $8.00 cy but that is for big placements. Might be a little more for a residential job.

 

[thrifty bill]

I got fiber in concrete six months ago, and it was obvious.

 

[Oldtymeflyr]

The fiber mesh is noticeable for awhile, then it seems to disappear. We have had it at two homes and its a good product.

As I recall its not an extra cost item for us. The concrete contractor may have just made it part of the quote. I could remove it but would get no discount.

I suggest that you replace the wire mesh with 3/8" rebar, it works

Good luck!

 

[sstruckguy]

I built 5 years ago, and I can still see the "little fuzzys" as I type this.(slab at my man door entrance)

All of my outside concrete has fibermesh in it.(driveway-porches-patois-sidewalks) I remember the conversation, but I don't remember why it is in there.

 

[pauls340]

I put fibre and wire mesh in my 24x25 slab and you can't see any fibre with a trowel finish. ALL trowel finishes will result in a laitance surface. I eliminated mine with a sprayon application of Vapor Lock 5/5 four hours after placement and my floor looks like a painted surface with ZERO moisture vapor emission problems.

 

[c39er]

Roll around on the slab without a shirt on and let us know what happened....and if you got the ichies!

 

[henrysgarage]

I used the fiber filler in my extention and it looks like the hairs seem to be sofened after years of being walked on and swept, will not try the ROF, not even laughing.

 

[ConCretin]

I suggest that you replace the wire mesh with 3/8" rebar, it works

That might be a little difficult at this point.

 

[bas157]

That might be a little difficult at this point.

yes, that would be difficult since I got the certificate of occupancy approval from the township on Tuesday morning. Just need to paint it, finish the trim and do something with the floor. Debating between epoxy coat or legacy industies (their sale ends tomorrow)

 

[Keithinsc]

Depends on your concrete supplier.

I had fibreglas hairs in one pour, you can easily see them in the finished pour, even after a sharp troweling and cure.

My last two pours, the yard used "buckeye" fiber. Nearly invisible. When the first bit of concrete came off the truck I told the driver STOP POURING!!, where is the fiber???
He handed me a sheet with this website.
http://www.ultrafiber500.com/faq_index.html
Learned me real quick.

You can see it barely in the splatter cookies that drop around, just take a cured piece and crack it in half, you should see some teenytiny whiskers, not like the 1/2-1" hairs from fiberglas.

Used the buckeye in two, 50+ yard pours and no cracks other than at the cut lines. Easier to finish and a smoother, easier to sweep floor.

 

[robertwhite]

I just had a huge slab poured and I saw the fiber being added. However after the slab was machine smooth with those whirley bird finish machine things, I have to look to see fiber.