How to Pour A Concrete Pad
Take Me Back to The Real Tim Jones Homepage DIY from The Real Tim Jones on Facebook DIY from The Real Tim Jones on Twitter DIY from The Real Tim Jones on YouTube DIY from The Real Tim Jones on Flickr Image Map

How to Pour A Concrete Pad

by TimJones on March 31, 2010


I LOVE concrete!  It’s one of the most amazing building materials!  You can do just about anything with concrete — pour the foundation of your home, create the walls of your home, create concrete blocks, patios, decks, fire pits, and more.  The list is pretty much endless.  You can even create pre-fabricated concrete panels that look like brick on the outside, tilt them up into place and in a matter of days, have a full structure built!  I love it!!!

Today, though, we’re talking about those little concrete pads that you need around your home that don’t require a full concrete truck — just a shovel, bag of Quikcrete, a wheel barrow, some water, and a plan.

Need a pad for your A/C unit?  Maybe a footer for a concrete block wall?  Or, as in the case of our project, a brick wall needs a foundation?  Regardless of need, concrete fills many of the holes in your DIY projects, very nicely.

With this project, we assume you already have your formwork built for the concrete pad that you’re building, since they vary so much.  However, just some basics on concrete formwork.

  • Make sure the formwork is level and square.  You wouldn’t want the pad to be out of square or tilted one direction or the other.
  • Concrete is heavy!  About 150 pounds per cubic foot.  Because of this weight, you need to make sure that your formwork is strong enough to hold the concrete.  Otherwise, it will just flow out of the forms and all over the ground.  Not much help for your project!  When in doubt, make the formwork stronger than you think you need.
  • Secure the formwork in place!  Don’t just build the formwork to create the shape your building.  Add some bracing to keep it in place.  Generally, this bracing amounts to a few stakes in the ground.  If you’re looking at a form that requires more than some staked bracing, you may be looking at a bigger project than we’re talking about, here.

As for the concrete, mix in the water, slowly!!  I cannot stress enough that you want to be miserly with the water.  The “drier” the concrete mixture, the more strength the concrete will develop over it’s curing time.  You still need to mix all the concrete with water, but you do not want it to become a soupy slurry mix.  This can happen with just a little too much water.  What you need is a “chunky” peanut butter-like consistency.  You’ll get an idea of this from the video.

Once you pour the concrete into your form, use a small trowel to finish and level the pad.  In some cases, the pad may be big enough to require a screed.  A screed is nothing more than some form of level (often a good, straight 2 x 4) to level the concrete when first poured into the forms.  You use the screed to move and level the concrete in the forms.  Once leveled, use the trowel to finish the concrete.  Some concrete pads may require or you may prefer a “non-slip” or non-smooth finish.  To accomplish this, finish the concrete as you normally would for a smooth finish, then gently drag a stiff, outdoor broom across the pad.  This will provide a rough “broom” finish to the concrete.

When you’ve finished the concrete to your liking, you’re still not done with the project.

  • To prevent cracking, keep the concrete wet for the next few days.  The curing process utilizes a lot of water and produces a lot of heat.  This will cause cracking, if the pad is not kept wet.
  • Immediately after finishing the concrete, cover the pad if it looks like it’s going to rain.  For the first 24 hours, rain could cause depressions in the concrete.
  • Clean all your tools!  You don’t need a trowel covered with concrete for your next project.  If you clean it now, it will come right off with water.  If you wait, you may be chiseling it off.

Let me know your feedback in the comments.  Have a strange shape you need to create with concrete?  I’d love to help!  Maybe a question about building formwork?  Or, maybe you have a really unique concrete structure — post it up in the comments and show it off to the world!

Related posts:

  1. DIY Home Improvement Measurements

{ 22 comments… read them below or add one }

Tim_Jones April 15, 2010 at 7:40 am

Thanks for the comment and for stopping by!

Mark S May 28, 2010 at 10:54 am

Hi Tim, Great article! I am planning to pour a small 1'x8' pad about 4″ thick for my deck block steps to sit on so I have a nice solid and level surface. For a small project of this size, would I need to add any rebar or wire mesh re-enforcement? Also, since the pad won't really be visible as the step will cover most of it, do I need to trowel finish it or will the screeding be enough to provide a level finish? Thanks!

Tim_Jones May 29, 2010 at 1:11 pm

Hi Mark,

I would recommend some WWF (welded wire fabric) in the footing you're describing. You could add some rebar, but that's likely overkill. In either case, make sure the concrete covers all of the metal by at least a couple inches on all sides.

As to finishing, you can just screed it, but you need to make sure that the aggregate is all inside the pad and not showing through the surface. Even though no one will ever see it, if the aggregate is not integral with the pad, it will not be as strong. You would just use a finishing trowel to work the aggregate into the pad. Also, a lot of “leveling” occurs in the finishing step, so just make sure the pad is good and level when you screed, so that your steps aren't out of level.

Tom Schlee September 10, 2010 at 10:02 am

When I have watched people do concrete, I observed that after the area was screeded they would wait for the concrete to 'set up' a little before they worked it with a trowel. I am doing a 3 x 7 heat pump pad for two outdoor units. How long after screeding do I wait before I do the finish troweling? Any other tips?

Wally January 19, 2011 at 1:41 pm

Hi Tim, I am looking onto pouring concrete for a new construction basement and I want to embed an electric heating cable within the slab. Is it possible to pour a thinner first layer, wait for that to set, install the heating cable on top of the first layer, then pour a second layer of concrete over top? Will there be bonding issues or cracking issues if this method is employed?

thanks!

elsie March 5, 2011 at 12:18 pm

I'm going to pour a concrete step coming off the patio. I want to run a pvc pipe underneath the step for watering purposes. There will be 3 separate steps, probably from 30-40″ wide, approximate, each with this pipe underneath. How will I prepare the form to allow for the pipe? Will the concrete crush the pipe?

Boris March 29, 2011 at 6:47 pm

Hi Tim,I poured a 3 1/2 x 5' concrete pad for a 6' tall brick oven. The pad came out great , and I put in plenty of rebar in it. What I didn't do is, pack the dirt before I poured the concrete. Since there's going to be a lot of weight on the pad ,bricks,blocks etc. ,do you think I should brake the pad up and start over.I live in Houston , there's a lot of clay in the ground , dirt suould be pretty solid. Hoping for an answer. Thanks!

Tim_Jones April 4, 2011 at 12:45 pm

Since you put a lot of rebar in the pad, you might be OK….however, clay is an expansive soil, meaning you might have some issues with cracking. If if were me, I would have over-excavated the clay out from below the pad and back-filled with sand and compacted it fully. As I said, though, you might be OK with so much rebar. Some other things you could do to prevent cracking without tearing out the slab: 1) Keep the slab wet while it cures (the longer the better). More cracking occurs from shrinking that earth settling. Keeping the slab wet and cool while it cures can prevent the cracking. 2) You could cut expansion joints in the slab. This essentially pre-places the cracks, as they're likely to happen, anyway. You might have to rent a concrete saw and just cut the joints partially through the slab.

shed plans April 28, 2011 at 6:59 am

This is a great guide if you plan a DIY for your home improvement. Great video.

Sam May 16, 2011 at 2:29 pm

 Thanks TIm you want to swing by MN and do it for me :) BTW, i think you’re doing a great job with the blog. Being an internet marketer myself, the video is well shot and ads to your site. I would probably remove one of the Google ad blocks though,Just my opinion). Thanks

Sam May 16, 2011 at 10:07 am

Awesome clip Tim. I need a 12' x 10' slab for a hot tub area next to my deck. Do you recommend a similar technique to your demo here, or is this not recommended for a DIYer?

Tim_Jones May 16, 2011 at 10:23 am

Hey Sam,I think you're right on the edge of a DIY vs. professional project.  Part of the issue lies with what you're putting on the slab.  Hot tubs (really, the water) is really heavy, so you'll need the right reinforcement in the slab to support that weight.  It's definitely something a more experienced DIY'er could do, but if you're fairly new to pouring slabs and figuring out the reinforcement needed for the weight, it might be best left to a pro.

Style Beton July 17, 2011 at 1:33 pm

Fantastic article for those who want themselves to improve their home.

Mark Chandra September 22, 2011 at 1:47 pm

Hi.
My basement wall is bowing inwards by 1-2 inchs. I am thinking of pouring a layer of concrete through out the wall. Do you think it is a good idea and will this reinforce the wall?

joe October 11, 2011 at 7:31 pm

Hi – I’m having a concrete pad put down next to my garage and side of the house. It was suggested that the new pad be pinned to the existing garage and house foundation. I’m not sure this is a good idea. What do you think of this suggestion?

TimJones October 17, 2011 at 11:40 am

By “pinned,” I’m assuming you mean to using rebar to connect the new slab with the old one and this is the traditional method of doing so. Obviously, when drilling into the existing foundation, you need to be careful of existing water pipes and electrical wires that may be “in slab.”

Louis January 22, 2012 at 7:35 am

Hi Tim,

I have an unlevel concrete basement floor, out about a inch and a quarter in places. I intend to pour a sand mix intended for thicknesses of two inches or less directly on the existing floor, using a concrete adhesive in between. Then I’m going to lay a subfloor on top. Is this sound?

Thanks,
Louis

TimJones January 23, 2012 at 9:32 am

Always check with manufacturers recommendations, but what you’re doing sounds good, except for one thing. You need a vapor barrier between the concrete floor and whatever subfloor material you’re putting down. You may even want to go with an application that provides sound and vapor barriers.

iona May 23, 2012 at 10:56 am

we need to build a pad for grain silos. so do we need rebar and if so how is the proper way for adding it in? the pad will probably be about 10×20 thanks

James K June 9, 2012 at 12:40 pm

Hi Tim,
I am pouring a concrete pad for the base of my deck stairs.
problem is the pad will be on a slight slope. the pad will be 4′d x 6′w.
I have already dug out the area, and made it level, but am wondering if I need to do anything to secure the pad to keep it from moving over time. currently one corner is 10″ deep, the diagnal is 6″ deep with the other two at 8″ deep. will need 4″ of compacted crushed limestone and have a steel mesh for the middle of the pad as it will have to be a minimum of 4″ thick. one person said to pound in rebar straight into the ground in an angle in a few spots within the pad, so its sticking up 2″ above the compacted gravel. another said to use treated wood in the same way (dont think that will last over time…) and have heard from others that the weight of the slab will hold it in place or even to put in 2 pillar foundations (below frost line). what do I do?

Peter Maldonado June 29, 2012 at 6:20 pm

Tim,

I am planning on doing a small bit of concrete for a sitting area in the front of our house. It will be for sitting and it is 8 feet by 12 feet. I formed it, but I am now wondering should I reinforce it with some mesh? No cars or anything else will be on it, except a small patio table, and 2 -3 people. I was just going to pour it, and finish it. What do you recommend?

Harry July 4, 2012 at 11:35 pm

I am pouring 2 colors of concrete in a sidewalk. I was thinking of creating the forms and putting rebar throught out the form and pour one color wait until it drys and remove form between colors and pour second color. What do you thing.

Leave a Comment

{ 1 trackback }

Previous post:

Next post: