How to Work with Concrete | Ask This Old House

This Old House landscape contractor Roger Cook explains masonry materials and then shows how to pour a concrete slab. (See below for a shopping list, tools, and steps.)

Roger teaches the differences between different masonry materials. Portland cement is added to many other mixes. Concrete is a mix of sand, stone, and Portland cement. A mortar mix is made of Portland cement, sand, and lime, and is used for bricks and stones above ground. Below ground, he uses a cement mix of Portland cement and sand.

Roger showed how to mix concrete by combining 3-parts sand, 2-parts stone (sometimes called aggregate), and 1-part Portland cement in a wheelbarrow. A power mixer can be rented.

Once the concrete is added to a form, Roger uses a trowel to smooth off the top, or he uses a push broom to add a slip resistant finish. He then uses an edger to round off the edge of the concrete, and then uses a groover to create a controlled joint for the concrete to crack.

Shopping List for How to Work with Concrete:
¾-inch stone, to form solid base for concrete slab

Tools for How to Work with Concrete:

Masonry materials and tools are available at home centers and masonry supply stores.

About Ask This Old House TV:
Homeowners have a virtual truckload of questions for us on smaller projects, and we're ready to answer. Ask This Old House solves the steady stream of home improvement problems faced by our viewers—and we make house calls! Ask This Old House features some familiar faces from This Old House, including Kevin O'Connor, general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook.

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How to Work with Concrete | Ask This Old House

[zaappp]

I like watching these guys at half speed. It's like watching a couple drunks trying to explain stuff to each other. Very entertaining if you have the time.

[itchyego]

Helps to mention for the beginner that "Grade" means simply the ground or the ground level, including its slope.

[danbytp]

Finally! Someone who explains it for us beginners so we can understand it, !!!

[korypankey]

I wish this guy was my teacher for everything. Concise, important and easy to digest information, no bs.

[Pallidus_Rider]

Tip: coat wood form with used motor oil for easy separation. 👍

[farhad.parsan]

very informative video, thanks a lot! I watched many videos on YouTube about pouring concrete and none were as simple and at the same time comprehensive as this one.

[guichuantang]

Excellent video on the difference and uses of concrete, cement and mortar which I was confused with!!

[Mchurchwell]

This is yalls best video yet. Very detailed for beginners.

[sleahcim]

The hard part to me would be the screening. When to do it. When to follow up with more screening. When to trowel. Thanks for leaving that out. I have not found a video yet to shoot it to me straight. Following a recipe is not an issue.
I did a small pad with premix from home depot and the finish was too rough. It looked horrible.

[samnoble]

Best concrete demo I've ever seen!

[crewmagnum]

I prefer mixing the sand and Portland thoroughly before adding the aggregate. It's a lot easier to get an even mix.

[rejahmuhyi]

Thanks for explaining the different kinds of cement .

[hawktuft]

I love reading the comments from all these self proclaimed experts. The guy is a professional. Sorry he doesn't do your way

[miguelsalami]

Hey that looks like a lot a Hod woik ya know ya gotta look out for those Shop Edges❗

[dachhisudarshan]

Love the watch Roger is wearing.... Classic all time best digital basic model.... CASIO F91 W i guess...

[bbbrickman]

Hi guys since you're using a gauged mix, to keep its tactile strength it should be; one pint of water for each pound of cement and good luck with that one, the mix would be so stiff it would break your arms when you try to travel it LOL, no offence intended, but what is referred to as 20 - two plenty in the UK would probably be your best bet mix for a home made concrete mix which would consist of 4 shovels or concreting gravel ( gravel and Sand premixed) you could use a trowel a spade or any other implement or a gloved hand come to that as long as it's not a gauged measuring implement, and one part of cement and enough water to bring it to a creamy consistency. Ps I have worked in the wet trade for over 40 years, but as for mixing it by the book, and as I was taught as an apprentice, many moons ago you are spot on,

[ChrisMichael]

Was really hoping you'd cover drying and curing, too.

[dvljet]

Concrete block aka cinderblock below grade you need to do a three step water proofing if you don't want leaks . You need to prime it then put your first coat of water proofing then you apply a mesh cloth then another coat of water proofing and then a dimple plastic . If you buy cinder blocks from a brick and block supply place they will have block ciment in bags just add water

[telosfd]

Mix the mixture down on the ground with the spades and then place it on the mold.

[glarochify]

Wow, thank you gentlemen, for putting in the work for this very informative video.