We have a single car driveway that we'd like to widen with a side extension for parking another vehicle.  I would also like to extend the opposite side a few feet and put a short walkway in leading to our front door (there's already a concrete step there).

What do I need to know about pouring my own concrete?  Is it something that I should get a pro to do, or can a reasonably competent person handle it?  Keep in mind, I'm not looking for a full driveway, just extensions to widen it and a short walkway.

The questions I've kind of been thinking about are:

1.  How deep should the concrete be?  It will need to support passenger cars and SUV's, nothing heavier.

2.  What should I do to prep the surface other than digging it out?  Do I need to lay something under the concrete itself, or can I just pour the concrete over the existing dirt?

3.  Do I need to break up the slabs (it will be about 20-30' long) to allow for expansion?  If so, how do I do that?

4.  Any advice on what to look for in the concrete?  How much should I expect the concrete to cost?  Is it realistice to think that I can mix my own, or should I do all the prep work myself and hire a company to bring in a mixer and pour it with me doing the leveling, etc.

5.  Any other tips or advice?  I'm sure there's many things that I've missed and will only realize once I'm ankle deep in wet concrete....

TIA

I'm no concrete guru, but I do know that you have to do a fair bit of work before you pour.  You have to compact the soil, then add a layer of gravel and compact that as well.

Have you calculated how many square feet of concrete you'll be pouring?

It'll probably be a total of 225 square feet.

Get a few qualified estimates first, It might not be as expensive as you think it will be.  

I would advise against doing it yourself unless you can get someone with experience to help you.

Typically, 4" is the thickness for residential type drives, sidewalks, etc..  For the driveway portion, it would be wise to use remesh wire or more expensive reinforced concrete mix.  If remesh wire is used, you pull it up to approx center of concrete as you pour.  Yes, you will need expansion joints impressed on your pour.  The concrete is not actually broken (it does that by itself), only grooved with a special tool.  It is also best to dig deeper than the 4" thick, allowing for a few inches of compacted gravel for the base.

1 yd of concrete at this thickness will cover 80 sq ft, so you are looking at about 3 yds.

As suggested by others, get some quotes.  There are lots of small contractors that would do this for a reasonable cost.

If you do it yourself, I agree you should enlist the assistance of someone who is experienced in concrete flat work.  I would advise against mixing your own on a project this size.  By all means, do not use the pre-mix bags from home improvement stores.

If done correctly, concrete will outlast any home.  Remember, it is an investment to improve your home quality and value.. don't cut corners.

Hope this helps - Good Luck!
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