Concrete Countertops: How reinforcing works

[sinnomor]

How close may the reinforcing be to the surface of the concrete?And what type of concrete would you reccomend for the following project?I am building a 14'x21(w)x2"(t) 16" of the width to be canted. 3" bearing using #3 on 16"centers for support and #9 ladder wire tied for tensile strength A 2x6 wall provides the 3" of bearing The rebar will be L shaped with legs of 8 and 20 inches,the 8" leg will be inserted into a3/8 hole in the 2x6 studs and glued the 20 "will support the slab Thanks

[sticks1215]

Very well explained. I am going to be building these in my house and needed to address these issues. Thanks for posting this.

[ConcreteCtopInst]

You're welcome!

[qsbux]

Easy to understand it :) Thank you

[902Jr]

Very interesting, and sound engineering principles applicable anywhere and everywhere.

[jsantoyoc]

Thank you very much for this footage. It made me understand much better how concrete-steel combination works. You are very clear and explain nicely.

[doof69er]

The part about reo placement was well explained.

I wish my civil engineering professors explained it as well as this!

[ConcreteCtopInst]

I'm sorry to hear about any cracking countertops! Exactly what I'm trying to prevent.

[SVKmellow]

2 people found this video after their countertop cracked...

[ConcreteCtopInst]

Thanks Oealnc for the nice comments.

Pkqkennywood, the answer to your question is essentially no. I've just posted a blog entry. Go to the home page of my website and click Blog at the top right.

Karenwaln, I will get to your question soon. It takes more than 500 characters to explain! Basically, I used 14 individual strands of 9 gauge ladder wire. The strands were placed about 1/4" apart in order to fit all 14 in a single layer within the beam's 6" width.

[karenwaln]

Great presentation! What I want to know is the reinforcement detail on your 8'x6"x1 1/2" plank. I assume you used the 9 ga. ladder wire? Did you put in some extra longitudinal pieces? Was there a less dense matt on the top surface with diagonal connectors between the two surfaces to handle shear forces? Could you achieve even greater strength with Carbon fiber, and how would that be configured? Very impressive!

[OeaInc]

Fantastic video! This was a really well thought out and presented explanation of reinforced concrete design. I have taken many concrete design courses and this is by far the quickest and most intuitive approach I have seen detailing tensile and compressive strength function and placement of reinforcing. Everyone needs to watch a good 10 mins of something like this, not just for concrete, but for the nature of materials and stresses for building. Thanks!

[pkqkennywood]

finally a video that actually explains something. can i use thinset with fiberglass cloth? is it a necessity to have a thickness of 1.5 to 2 inch thickness?

[ConcreteCtopInst]

Wooden tops on the cabinets will not provide structural support. Wood is too flexible and weak, so you still need the proper steel reinforcing in the concrete. The dimensions of the cabinets are fine - the concrete countertop will lay over top of several cabinet boxes, depending on the layout of your kitchen.

[lovebug11768]

Great info. Do you need to put in reinforcements if your cabinets already have a wooden tops which the counter will lay on. My cabinets have odd dimensions too (I have one of those weird, modern kitchens). Some cabinets are 12" X 40", 12"X14", 24"X30". Should I bother putting reinforcements in these or are they too small?

[ConcreteCtopInst]

Planetary polishers are a fantastic tool that makes producing smooth, flat and gouge-free surfaces fast and easy. Justifying their cost (and the tooling - in triplicate!) is something you need to determine. Do you do a lot of large, flat countertops? Do you or your employees struggle with keeping a single headed polisher flat? If so then maybe a planetary polisher is a valuable asset. You will still need a single-headed polisher for narrow sections, edges and inside integral sinks.

[TruthinFilm]

What is your impression of the DS301 grinder for concrete countertops? It's a whole lot of money, but if it's as good as they say...

[ConcreteCtopInst]

A piece that small won't need reinforcing, provided it's at least 1" thick. Set the piece just like a tile with a full bed of thinset mortar.

[blackduck8891]

What if any reinforcement do you suggest with a fireplace hearth. dimensions are 24"x36" with 45 degree corners

Thank you

[therealeeeo]

This is a phenomenal video. I'm a contractor but have had no experience with concrete countertops up until now. I'm remodeling my own kitchen, and have decided it would be a good time to use myself as a guinea pig for my first attempt at making concrete countertops. Thank you!

[ConcreteCtopInst]

@therealeeeo Best of luck with your first project! Definitely you will be your best guinea pig. Just FYI, I do have a self-study course designed for just this scenario - making your first (successful) concrete countertop: Check out the Level 1 self-study training on my website.

[ConcreteCtopInst]

You're welcome!

[jaccigalindo1]

thank you for your knowledge in reinforcement i learned quite a bit

[ConcreteCtopInst]

Thanks everybody, I'm glad this video is helpful. courduroycarver, AR glass mesh is also called "scrim". Fishstone Concrete Countertop Supply and Ball Consulting sell it. Fishstone sells it in small quantities.

[david18861886]

Thanks!!! This is what youtube should be full of. Not 2012 idiocy.

[corduroycarver]

You mention AR glass mesh. I have searched online for this and I've been unable to find it except in very large quantities from overseas. Is there a special store that usually carries alkali resistant glass or should I start snooping around my local concrete countertop shop?

[GNO89]

Excellent video on the explaination of forces to a countertop.

[ilgesmccool]

Really wonderful video. Easy to understand and apply. Great pictures to go along with your wording. So happy I found this.

[TruthinFilm]

very educational, thanks

[duplessis2006]

fantastic now i am feeling more confident about doing my own countertops

[mmedeiros09]

Great video - you have a solid knowledge base of reinforced concrete.

[tizilondres]

Hi, Thanks for the video clip. Very very interesting.

Is there any simple calculation to work out the amount of steel needed to reiforce a beam or a foundation strip?

many thanks and god bless.

[ConcreteCtopInst]

There really is not a simple calculation. It depends on the geometry of the slab, including orientation of the tensile forces, sink holes, etc.