Concrete over Raised Wood Floor @ Garage

[smokiibear]

I saw somes posts regarding subject at this thread:

http://www.eng-tips.com/viewthread.cfm?qid=227077

Mike mentioned using l/1000 as deflection limit. Would this be dead & live deflection or only live?

Thanks,

Smokii

 

[SteelPE]

Only briefly took a look at the thread but I would imagine that limit would apply to loads that are applied after the concrete has hardened. That may include a portion of the dead and all of the live depending on the construction sequence.

 

[msquared48]

Yes, that is what I meant.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[smokiibear]

I'm sorry I don't undertand. Yes to one of three options posted

 

[msquared48]

Sorry.

I normally would set the limit to the live load deflection at L/1000 as that is what will be working the concrete vertically after it cures, as SteelPE mentioned.

That being said, I would still set the total load deflection at L/600 so as not to have too much ponding of concrete, increasing the load further to the floor joists, if you know what I mean.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[smokiibear]

Ah...thank you, Mike. Yes...that helps. I understand the concept, but how did you arrive at 600 for total load as opposed to some other number?

 

[JAE]

It does depend on whether the wood support is temporarily shored or not. Once the shoring is removed, the concrete will "feel" its own self weight as well as the live load later.

 

[msquared48]

Unshored JAE, unless the span is too great for the depth of lumber that can be tolerated.

L/600 is the standard for brick masonry walls, so I just adopted that and it has worked just fine.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[smokiibear]

Thanks. I appreciate the help!