timber shed
timber shed
(OP)
I need to design a timber shed (50’x 40’x15’(h)) located on the top of a mountain. The mountain is 600’ high from ground. Basic wind speed for this area is 120 m/hr. The uplift pressure therefore could come to 85#/sf. Is any one familiar with this situation and can give me suggestions as for what kind of Simpson tie I should use to prevent roof from blowing away?
Since it is a open shed. There is no shear wall. What kind of bracing system is the best here to provide lateral resistance and, in the other hand, it does not block the opening?
Please advice and thank you very much.
Since it is a open shed. There is no shear wall. What kind of bracing system is the best here to provide lateral resistance and, in the other hand, it does not block the opening?
Please advice and thank you very much.






RE: timber shed
Shear walls are the way to go. Assuming you have one side mostly open (like a garage), you'll have a torsional effect. Reference a code like the IBC 2003, or ASCE 7 to get the different load combinations and factors for wind analysis. I highly recommend the book "Design of Wood Structures - ASD" 5th edition by Breyer. If you read the whole thing, you'll be able to design this shed.
RE: timber shed
Thanks for response.
I cannot build a shear wall because four sides of this shed are supposed to installed big windows. There is no interior wall in this shed also. I guess that a moment frame at each end of shed is needed to provide lateral resistance
The Book by Breyer does not talk about timber framing design. Especially I would like to know how to design a moment connection for laminated framing. Can you help?
Meng
RE: timber shed
DaveAtkins
RE: timber shed
I apologize if you bought the Breyer book on my recommendation and it wasn't what you needed. I assumed when you said timber that you meant conventional wood framing or glulam members (which it has both). I'm not aware of a good timber design book.
An idea which I have never used (I don't work with timber, and haven't done this with typical stick framing) is to set the posts in a concrete pier, so that they will cantilever up, meaning you won't have to create a moment frame at the top of the column. You will obviously have to design both the post and the pier for the lateral loading, as well as check your local building code to see the requirements for embedding wood in concrete. In the IBC 2003, it requires the wood to be preservative-treated wood.
RE: timber shed
RE: timber shed
RE: timber shed
RE: timber shed
Steel frame was my first choice originally. However, my contractor told me he could not lift the steel beam because he could not drive truck to the top of mountain.
Using concrete fixed footing is a good idea. I will try it if I cannot get a timber frame. Conc. can be hand mixed anyway.
When timber embedded in concrete, will it create a corrosion problem even it is treated?
Mark
RE: timber shed
best idea if you want wood.
AITC has a straight forward method of designing a "pole barn", which this construction would be classified.
If it is a simple shed you don't even need to embedd the posts in concrete; you can embedd in a large hole and
tamp in crusher run. As the poles move it will actually compact the crusher run (with fines) tighter.
RE: timber shed
In regards to a moment frame using wood, I have seen a few new details here in the midwest where they use for the connection angles with through bolts that tie together the members and they create a "semi-rigid connection" Analysis of the bearing due to the lateral forces is posible and not that complicated.
Good Luck and hopefully brings up more ideas.
RareBug
RE: timber shed