×
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

Standing Seam Metal Roof Canopy

Standing Seam Metal Roof Canopy

Standing Seam Metal Roof Canopy

(OP)
I am currently designing a standing seam metal roof canopy. Yes, I did provide a wide rib steel roof deck below the standing seam roof, so no diaphragm issues. The support framing is structural steel (curved beams), on steel tube columns, on concrete piers and footings. It is a stand alone canopy at an amusement park.

My client (local public works engineer) is wondering if the summer heat will cause the steel roof deck (not the standing seam metal roof--it is able to slide on its support clips) to expand, resulting in failure of the deck welds. I am currently just showing standing seam directly on steel deck--perhaps I should provide rigid insulation, to prevent the hot standing seam roof from transferring heat to the steel deck? Seems strange, because this is an unheated structure.

DaveAtkins

RE: Standing Seam Metal Roof Canopy

DaveAtkins...yes, provide the insulation and a "slip sheet" between to allow for differential movement.

RE: Standing Seam Metal Roof Canopy

How big is the structure?

RE: Standing Seam Metal Roof Canopy

While I think adding insulation is cheap insurance, my gut tells me expansion of the deck would not be an issue. If you ran the numbers and calculated the actual linear expansion and the resulting stress on the welds, I would expect the effects to be very minimal.

If you were to get significant expansion due to changes in the ambient air temperature, wouldn't you also have to add insulation to the bottom of the deck since it would be exposed to the ambient air? (I assume the discussed above was to only add insulation between the deck and standing seam roof)

I have used exposed roof deck in warm climates and have not heard of this being a problem (typically used in industrial applications for shielding, canopy, or storage structures)

RE: Standing Seam Metal Roof Canopy

Can the continuous spaces between the wide-ribs and below the standing seam panels provide vent spaces to remove the heated air?

RE: Standing Seam Metal Roof Canopy

(OP)
The canopy is 19' wide by 28' long. So maybe this isn't a big deal after all.

DaveAtkins

RE: Standing Seam Metal Roof Canopy

Another alternative might be to use Hilti pins instead of deck welds. The pins have some give and would not fail in a brittle manner as the welds might. I'm not sure if there are issues with using pins in an exterior application.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Standing Seam Metal Roof Canopy

…..or even self drilling screws if the flanges are not too thick

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