Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Concrete Pad on Grass

Concrete Pad on Grass

Concrete Pad on Grass


Recently I got 11'X11' concrete pad built in my backyard. Some contractor in my neighborhood was working and I got him to build this pad for me. He built it while I was away at work. Later when I checked my security cameras, I saw that he built it on top of grass without digging the grass out. He poured gravels on top of grass then compacted them and then poured about 5" concrete on top of it. I have never heard of anyone doing it this way. Should I be concerned?

RE: Concrete Pad on Grass

Depends on what you are putting on the slab I would think.

RE: Concrete Pad on Grass

I am planning on building 10 X 10 storage shed on it.

RE: Concrete Pad on Grass

Since the slab is 5" thick, it's likely strong enough, so the question becomes, is the likely inch or so of settlement going to be a problem.

RE: Concrete Pad on Grass

A 10x10 residential use shed is likely to carry a very light load compared to some of the projects we see in the commercial/industrial world. However, if one of us were building it in our yard, we would have a 12-inch thick slab with #8 bars every 6 inches "just to make sure."

RE: Concrete Pad on Grass


Not me. I have done exactly as the OP's contractor did.

RE: Concrete Pad on Grass

For a storage shed slab, I'd most likely do a 4" unreinforced slab, or 3" reinforced with mesh on a compacted base of crushed rock. 6" around the edges to embed anchors for the wall. I calculate what's needed, so I can be sure without wasting money.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close