Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Ceiling deflection damage caused by excessive snow - who is responsible

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I have a friend who designed a commercial building in Pinion Crest - an area in the mountains near Palm Springs California. The roof was designed to state and municipal code using top chord sloped Trus-Joist products. My friend is actually the designer, he hired the engineer and the joists were verified by design from Trus-Joist.
The joists span a maximum of 25 feet and I have no other information at this point on the type and spacing of the sloped joists. However, I think this is secondary to the issue.
The joints at the Gypsum Ceilings began to split. The TJI calc's verified that the joists were within the allowable deflection range (although allowable deflection for 25 feet may still be too much to prevent gypsum damage if paper tape is used). The owner is demanding that my friend (who was also the General Contractor) on the project repair the damage and upgrade the roof at his cost.

Although I have not confirmed it, I believe that the snow load for this year probably exceeded the code limits. The owners expert claims that the Gypsum Association states that the deflection criteria for a gypsum ceiling (total load) shall not be greater than L/240. I have asked to have the calculations faxed to me but I can no imagine Trus-Joist being less than conservative on their design and would like to verify this.

Assuming that Trus Joist is accurate and the joist calc out, then the only answer is that the roof live load was exceeded by the amount of snow load exceeded the code allowable. In my opinion, this is an Act of Nature and the owners insurance should cover - it is not the responsibility of the EOR, Trus-Joist or the Designer/Contractor.

Any thoughts on this matter before I decide to step in and represent my friends position? Am I missing anything? I am hesitant at this time to go into much more detail until I see the calculations produced by Trus-Joist, but I would be interested in your comments.

Dennis S. Wish, PE
California Professional Engineer
Structural Engineering Consultant


760.564.0884 (office - fax)

This e-mail is intended to be delivered only to the named addressee(s) and may contain information that is confidential and proprietary. If this information is received by anyone other than the named addressee(s), the recipient(s) should immediately notify the sender by e-mail and promptly delete the transmitted material from your computer and server. In no event shall this material be read, used, stored, or retained by anyone other than the named addressee(s) without the express written consent of the sender or the named addressee(s).