×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Slab on Grade at Doorway

Slab on Grade at Doorway

Slab on Grade at Doorway

(OP)
I'm trying to come up with a good detail at the doorway of an industrial building. I'd planned on having the perimeter grade beam come up about 6" above the slab on grade and leave the slab on grade 'floating'. But at the doorway, throw a couple of dowels in and notch the gradebeam down 6", or would you notch it further and run the slab over top at the doorway. It's been a while since I've designed a concrete foundation and I can't remember what is (or if there is a) standard way to detail the door openings.

RE: Slab on Grade at Doorway

If you are in an area where frost heave is a concern, you are asking for trouble of you don't dowel the doorway stoop into the building and provide a perimeter frost wall.

The dowels will prevent the stoop from heaving and blocking the door at the doorway and the frost wall will prevent frost heave and keep the stoop from becoming unlevel (preventing the door from swinging open)

RE: Slab on Grade at Doorway

We usually drop the perimeter grade beam below the slab and have the slab extend over the grade beam to the outside face of the grade beam.
This results in a single slab joint (between interior slab and exterior pavement) instead of two twin joints on either side of the grade beam, with the grade beam top exposed.

As far as heaving, if we drop the grade beam and extend the slab over the top, there is a concern (as MotorCity mentions) of the earth just inside the grade beam freezing and heaving.

However, you can and should have perimeter insulation placed on the inside face of the grade beam anyway (in non-door areas) and this insulation (usually 2" thick rigid in our region) would extend up the inside face of the grade beam and turn horizontally under the slab for 2 feet or so. This protects that dirt from heaving to some extent.

Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies

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!


Resources