Rafter size for 16ft Span

[/pine]

I asked you for documentation on your statement, not your attitude.

lighten up...
I directed you to Google...how you got an "attitude" out of that is over the top...!

again...why do you need documentation?...it's like asking for documentation that "rock smashes scissors"

 

[nickel plate]

why do you need me to provide documentation? try Google...

The key word is "strength" and the orientation of applied forces...

Actually there are a lot of woods (and many other softer materials) that are stronger than steel (by weight) in the correct orientation to the grain...

also if you're the doubting type...I guess you won't believe that (common silica) glass is one of the most "elastic" materials on the planet...

Your paragraph beginning with "also if you are the doubting type..."
I am not a doubting type, I am one who seeks collective knowledge and when I read a statement pertaining to the strength of wood being more than steel, I want to further read the documented sources of the author, in this case it's you. I have never projected doubts toward your earlier wood vs.steel statement, I just asked for your references.

 

[JDGreenGrass]

Although a shorter span, the principles apply. I had a disaster of a small barn i inherited with the place. It too was an 18' span, with a 2/12 pitch. It was saggy and leaked no matter what repairs were made. Enough!! We did a tear off of the shingles, sheathing and pulled all the rafters off. I reversed the pitch of the roof. I extended the wall height an additional 2 feet which allowed me to go to 5/12. I reclaimed the old rafters, and cut birdsmouth, upper and lower. I have 9" over hangs with rafter cuts. I faced them with 1 by.

The added pitch and height allowed me to put a small loft at both ends for storage. It is all shingled as of last night. The deck is OSB with good tar paper underneath and drip edge all around.

This week, I will side it with vinyl, mostly because I reclaimed the vinyl that was on it and I won't have to paint, ever. Might have preferred steel, but this project was a re-do and re-build and I have very few dollars in the project.

Hopefully some of these pix might give you a few ideas. Best regards on your new barn/shed.

Thanks for posting the pictures bp. Gives me great ideas for the tractor shed I want to build. Just like that with a good sized door on the short end. Would fit nicely where I want to put it, salt box style only with one slant roof. Loft is good too.

Funny, but those pictures helped clear my mind with some good ideas.

 

[bp fick]

Just my opinion but I think using 2x12 or even 2x10 ceiling joist for a 16' span is way over kill and very expensive. Also with 2x10 or 2x12's if you draw out the angles of a 2/12 roof pitch I think you will see how much of the joist you will be cutting to fit at the wall plate. A 2x12 that ends up being 3 to 5" at the wall hasn't added any real strength to the ceiling. I'll be surprised if you don't find engineered trusses the cheapest way to go and it will also save time.

MarkV

There is a 2/3 rule on cutting rafters. No rafter is ever to be cut more than 1/3, leaving 2/3 of its original size when cutting dovetails or birdmouths.
Do some violate this rule of carpentry? Sure. But they waste their money on a larger rafter size. YouTube search rafter cutting. There are some great instructional videos available.

Thanks for posting the pictures bp. Gives me great ideas for the tractor shed I want to build. Just like that with a good sized door on the short end. Would fit nicely where I want to put it, salt box style only with one slant roof. Loft is good too.

Funny, but those pictures helped clear my mind with some good ideas.

You are most welcome.

 

[/pine]

Your paragraph beginning with "also if you are the doubting type..."
I am not a doubting type, I am one who seeks collective knowledge and when I read a statement pertaining to the strength of wood being more than steel, I want to further read the documented sources of the author, in this case it's you. I have never projected doubts toward your earlier wood vs.steel statement, I just asked for your references.

I apologize if my missive came across other than intended...it was not my intent to doubt your sincerity...

In hind sight...I should have addressed the later part of the reply to all readers (doubting types are common here)...honestly though..all my working life (shipwright) I have heard that wood (pound for pound) is stronger than steel...and in all my 50+ years of experience I have seen hundreds of examples of why it is said...

for technical evidence try:
http://www.swst.org/teach/teach2/properties2.pdf

open the document and navigate to page 47 or search for the word "steel"

cheers...

 

[boxygen]

Southern Yellow Pine is one of the hardest softwoods there are, it is harder than some hardwoods, poplar comes to mind. In these parts, no one would use spruce over 2x6 for framing. Douglas Fir maybe, but avialiable and cost is an issue.

Thank You. Read a lot of TBN, but contribute very little usually. This is because so many people here so much more knowledge than I on the topics discussed. I make sure that I'm 100% confident what Im posting is accurate before I make a post, I often wish others would do the same.:confused2: Dont get me wrong, Spruce is very suitable for framing, however SYP is DEFINITELY stronger. Unless all those engineering books and professors were lying to me the whole time.

 

[tommu56]

Truss joists how to

http://www.ilevel.com/literature/TJ-9001.pdf

the load tables are on their web site

for that flat of roof it would be almost a "floor"

tom

 

[nickel plate]

I apologize if my missive came across other than intended...it was not my intent to doubt your sincerity...

In hind sight...I should have addressed the later part of the reply to all readers (doubting types are common here)...honestly though..all my working life (shipwright) I have heard that wood (pound for pound) is stronger than steel...and in all my 50+ years of experience I have seen hundreds of examples of why it is said...

for technical evidence try:
http://www.swst.org/teach/teach2/properties2.pdf

open the document and navigate to page 47 or search for the word "steel"

cheers...

Accepted /pine. Thank you for understanding my concerns.

 

[whitedogone]

Hiya,

Looking for information/feedback.

Finally, I am going to build the workshop.

I am looking at having a 16 ft span on on a simple shed roof with a 2/12 pitch.

I am in Central texas, so there is no snow load.

I am trying to decide on the size of the rafters and spacing and I am looking for feedback from people who have experience with their buildings.

Depending on the tables, I look at, I can do 2x8, 2x10 or 2x12. My preference would be to stay at 24 oc, but I am willing to drop to 16 oc to add strength and drop to 2x8s (general easy of handling).

Any feedback would be appreciated.

Thanks

Although I'd probably use trusses (cheaper,faster,lighter) Here's some SSL data:

I assume you would mostly have SYP in your local

LL=20
DL=10
limited to L/180 (no ceiling attached)

#2 2x8@24"oc will span 15'-10" (This will be work since you will most likely be less than that inside of plate to inside of plate.)

 

[dfkrug]

USTMD, here I am setting my homemade steel trusses for my "tractor port".

With my boom pole, I can set these without any helper, which is nice.

I don't know if you consider cost, but each of my trusses is about $50
in materials, and can be lifted (if you have to) by one person. I do not.
You should be able to do better in TX. All manufacturers have span
tables to consult. I have a 17' span, and a 4/12 pitch. Spacing is 24"
OC, except for the outer 2 trusses.

I doubt that you can do better with pre-built engineered trusses-wood
or steel.