Messing with Sketchup - my cabin idea

[Ljohnsaw]

 So here is my attempt at Sketchup and my cabin thoughts.  This is very rough, not nearly finished (no braces or purlins, joints, etc).  This plan will be discarded as I have major difficulty in Sketchup modifying major elements.





I plan to have a full basement with a 4' metal access door and maybe a 9' roll up.  Stairs at the opposite end come up between the bedrooms.  In front of the bedroom on the left will be the bathroom and then the kitchen.  Only the bedroom and bathroom walls are shown.  I was working on a bent spacing of 12' 8' 8' 12'.  The 8's would be the bathroom and kitchen with a common wall for water/waste.  The actual bedrooms will be 10x10 because the closets will be within the bent area. 

So now the problem, the span of 12' for the purlins is just too great - the purlins end up needing to be MASSIVE.  At 8', they are manageable.  So I figured I'd add another frame and split the 12's to a pair of 6's.  The reason for the queen posts is to set up a space for the stairs and I just continued the elements forward.  The posts will continue down through the basement.  The great room is looking a little claustrophobic so I might make the pair of 6's into a pair of 8's.

Please, point out what I may be doing wrong or offer suggestions to improve.

Thanks!

[Jim_Rogers]

Dimensions showing would be nice. Or post the plan in the sketchup section and we can download it and review.

What makes you think the purlins will be massive? Can you post your details such as snow loads, spans again, type of wood, spacing?

One center post would open up the middle of the floor plan. Speaking of floor plan, can you post that? Or a picture of that.

Jim Rogers

[Ljohnsaw]

Jim,

Here are the particulars and a floor plan with dimensions (this is modified from the views above):



 

Starting at the roof and working down:

My area has a snow value of 303 PSF.  I will be doing a 12/12 roof, heavily insulated and a metal skin so my thermal rating is 1.2 and the roof snow load calcs out to just under 116 RSL.  I added a 40 PSF live load even though I only need 30 per code.

Assuming that is correct, I make a guess of 2 foot on center purlins running 12 foot over the bedrooms and 8 foot over the front rooms (without the extra bent I've inserted on the floor plan).  If I sheath the area with 2" pine or, preferably, cedar at 24 lb/cu-ft, I have an additional dead load of 4 PSF.  My total load (RSL + Live + Dead) is 160 PSF not counting the insulation, metal and the purlin.

The beam calculator starts at the top asking for total load on the beam which I calculate as 160 x 24 square feet (12' x 2' spacing) = 3840 lbs.
Next it asks for the dead load.  For now, I'm just using the planking at 4 PSF x 24 = 96 lbs.  Beam span is 144 inches.

Width and depth of the purlin are just guesses until I pass.

Species I have is Ponderosa Pine and the building department basically says I have to build to #2 grade - so that is what I pick (under B+S).

I don't get a "pass" on all three until I go up to a 7x10 purlin!  To me, that is big - granted that is a tremendous load it has to carry.  ((However, if the physical spacing of the purlins is at 24" and you use the projected floor plan view spacing, that is reduced by a factor of 1.414 (45* angle).  The load drops in proportion and the purlin rating becomes 5x9  -- is this correct???))

If I take it down to an 8 foot span (96") for the front parts of the cabin, my purlin size can drop to 5x8 - smaller, manageable.

Dropping to a 6 foot span (72"), I'm down to a 4x7 but for aesthetics since they all will be visible, I would keep it at 5x8.

Now to do this correctly, I suppose I would have to add to the dead load the weight of the purlin as well the rest of the roofing materials?

I'm hoping my use of the tool is erred is some way.

I could move the center post pair to the middle, but that complicates the placement of the supporting beams for the floor and/or lengthens the floor joists by 20%.  I'm not down to that floor level yet so I'm not concerned with it at this point.

Also a question: For the sill beams, I'm thinking incense cedar (rot resistance?) 8" thick and wide enough to fit the posts (whatever they eventually calc up to be) plus enough to catch the bottom of my wall planking (1"?), the rigid foam insulation (5") and Hardi Plank exterior boards (Too many wood peckers!).  That makes for a 8x14 with 6" hanging out side the foundation (as seen on my floor plan above) if the posts end up being 8x8s.

[Brian_Weekley]

Just my opinion, but from an aesthetic perspective, that long narrow "hallway" on both the lower and upper levels would drive me crazy.  I seriously doubt you need four posts per bent for only a 24 foot wide building.  Try running your calcs with only a center post on the bottom level and widen the queen posts on the upper.  I think that would help open up the space and not make it so claustrophobic.

[Jim_Rogers]

ljohn:
thanks for posting the floor plan.

You said: "My area has a snow value of 303 PSF."
and: Is there a decimal point missing there? 303 pounds per square foot?

Later you say: "the roof snow load calcs out to just under 116 RSL."
and: Something doesn't look right here. If you have a 303 pound snow load how can the roof load now be 116? And what is the "R" in RSL? I'm assuming SL means snow load.

Also, both of your drawings don't show any purlins. What timbers are you calling purlins?
Did you omit them? (I see by your original post that you did. So I'll assume you know what a purlin is and where it is placed, between the rafters).
It's hard to verify your numbers without seeing the actual timber or the sketchup plan.

Having that many posts does seem like a lot.

And having one center post would make more sense if your floor plans will allow it by offsetting your hallway to one side.

If you want a centered doorway to the outside, then the outside bents can have four posts so you can do that. There is no reason why all bents have to have the same amount of posts.

Floor joists should run from bent to bent. Tie beams to hold up the floor joist would increase by some amount but they have to join some place in the middle unless you're going to buy or mill 24' long tie beams.

One thing I use to determine frame layout is the length of the longest piece of timber you can buy or mill. If you can't mill or don't want to buy 24' long timbers then don't design for them.
Are you buying timbers for the project or milling them yourself?

I want to discuss your plan more with you, but I'll wait till I hear back from you about these questions I have.

Jim Rogers

[Ljohnsaw]

Jim,
I'm surprised that you didn't answer first!   You're speed and thoroughness is always welcomed!  OK, point by point.

ljohn:
thanks for posting the floor plan.

You said: "My area has a snow value of 303 PSF."
and: Is there a decimal point missing there? 303 pounds per square foot?

No, that is correct.  If I go another 1,000 feet up in elevation, it is 450 PSF.  This is from the County's web site specifically for my property.  If I use another web site for the adjacent county (I am about 1,000 feet away from the boarder) it shows around 330 PSF.  Look up the definition of "Sierra Cement".  Keep in mind that two years ago, I had 19' of snow on my property.

Later you say: "the roof snow load calcs out to just under 116 RSL."
and: Something doesn't look right here. If you have a 303 pound snow load how can the roof load now be 116? And what is the "R" in RSL? I'm assuming SL means snow load.

I will have to go back and find the link but you have to convert the Ground Snow Load (GSL shown above - 303) to a Roof Snow Load (RSL).  It takes into account your roofing material (rough holds snow, slick lets it slide off), roof pitch and thermal qualities.

Also, both of your drawings don't show any purlins. What timbers are you calling purlins?
Did you omit them? (I see by your original post that you did. So I'll assume you know what a purlin is and where it is placed, between the rafters).
It's hard to verify your numbers without seeing the actual timber or the sketchup plan.

I left the purlins off for clarity and because I'm lazy.  :D  I didn't see the point in drawing them since my drawing was done totally wrong (no joints), I didn't have a size yet and I was going to re-draw very soon.  Yes, they will run between the rafters parallel to the ridge.

Having that many posts does seem like a lot.

And having one center post would make more sense if your floor plans will allow it by offsetting your hallway to one side.

If you want a centered doorway to the outside, then the outside bents can have four posts so you can do that. There is no reason why all bents have to have the same amount of posts.

Point well taken by you and others.  I will re-design that aspect.  Again, I was being lazy for the engineering calcs - transferring the loads to the foundation below.  The point of the queen posts is to help reduce the overall size of the rafters that I'm assuming would be so huge without the rafter tie it would be ridiculous! 

Floor joists should run from bent to bent. Tie beams to hold up the floor joist would increase by some amount but they have to join some place in the middle unless you're going to buy or mill 24' long tie beams.

I am building a mill and will be able to mill 24' - hence the width of the building.  I want the floor boards to run the length of the building - I think that looks better, personal opinion.  So, the joists need to run across the building.  I'm going to do stick framing for the main floor so the floor joists may end up being placed on top of the sills and one or more beams running the length of the building.  Other ideas welcomed  :P

One thing I use to determine frame layout is the length of the longest piece of timber you can buy or mill. If you can't mill or don't want to buy 24' long timbers then don't design for them.
Are you buying timbers for the project or milling them yourself?

Attempting to use all my own cut wood - hence the question about the sill plates.

I want to discuss your plan more with you, but I'll wait till I hear back from you about these questions I have.

Jim Rogers

As always, Jim, I appreciate you sharing your knowledge and experience!

[Jim_Rogers]

Thanks for your quick reply.
Ok, so now I understand your first floor framing layout of joists going across the 24' span from long sill to long sill.
My comments about the floor joist running from bent to bent were for the second floor framing.
We have two framing circumstances and we need to figure the framing for both. And we should state which framing we're talking about.

I understand your decision to not show the purlins on your first drawing.

I understand, now, your "R" snow load.

My next questions have to do with the type of roof system you have picked out.

You have discussed purlins with rafters. Which is known as a principal rafter/purlin roof system.
The other kind of roof system is the common rafter roof system.

I was wondering why you chose that roof system?

Do you understand the difference in assembling a principal rafter/purlin roof system vs a common rafter roof system?

A principal rafter/purlin roof system requires a lot more "rigging" equipment to erect the frame. You have to hold up or out one bent while you fly in the purlins between the rafters.

Here you can see a standing bent and some of the rigging used to hold another bent while the crane is used to fly in the roof purlins.



This makes assembling a frame a little more complex.

I don't want to "talk you out" of your ideas, I just want to understand if you understand the methods you'll have to use to assemble the design you are creating.

Jim Rogers

[Ljohnsaw]

Thanks for your quick reply.
Ok, so now I understand your first floor framing layout of joists going across the 24' span from long sill to long sill.
My comments about the floor joist running from bent to bent were for the second floor framing.
We have two framing circumstances and we need to figure the framing for both. And we should state which framing we're talking about.

Agreed - for the main floor, the joists will go the short direction so the flooring can go the long direction.  For the loft (second floor), the joists will go the short direction so the floor can run the longer dimension.

I understand your decision to not show the purlins on your first drawing.

I understand, now, your "R" snow load.

My next questions have to do with the type of roof system you have picked out.

You have discussed purlins with rafters. Which is known as a principal rafter/purlin roof system.
The other kind of roof system is the common rafter roof system.

I was wondering why you chose that roof system?

Do you understand the difference in assembling a principal rafter/purlin roof system vs a common rafter roof system?

A principal rafter/purlin roof system requires a lot more "rigging" equipment to erect the frame. You have to hold up or out one bent while you fly in the purlins between the rafters.

Here you can see a standing bent and some of the rigging used to hold another bent while the crane is used to fly in the roof purlins.



This makes assembling a frame a little more complex.

I don't want to "talk you out" of your ideas, I just want to understand if you understand the methods you'll have to use to assemble the design you are creating.

Jim Rogers

I understand the principle rafter/purlin roofing system and the associated assembly requirements.  While the bent is bigger/heavier, it seems stronger to me with a better attachment of the principle rafter to the rest of the frame.  What I didn't show it that I will have some eaves (size yet to be determined).  I plan to hang a purlin out near the end of the principle rafter past the exterior walls.  I don't see how to do that with timbers using common rafters - the necessary cuts for the bird's mouth seem more difficult (not to mention so many of them!) and leave little strength for an eve portion on the rafter.  As you can see, I'm dealing with some substantial snow loads so I want to err on the side of robustness!!

I've read the three major timber framing books recommended by many here (once through) and will be reading them again.

And don't hesitate - talk me out of my ideas!  I'm a complete novice on this scale of furniture timber frame construction. ;)  Please tell me your opinions on what are the better way to do things.  Now is the time, before I start cutting!

My goals are simple: 1) have some fun building something that I can be proud of and my descendents can enjoy (i.e. comfortable and durable), 2) teach my son the joys of building (big things) - he already love to create on a small scale 3) utilize my own timber to the greatest extent possible and 4) have a nice place in the woods for my retirement - very soon  8)

[Ljohnsaw]

OK, revised floor plan:

On the right are two bedrooms with closets shown as the tall rectangles.  The 4' hallway is actually the stairs going down to the basement.  I will have a pull-down staircase to go up to the loft in this space as well.  I'm planning on the loft covering the bedrooms, bathroom and kitchen (to facilitate overhead lighting).  The bathroom and kitchen have grown by 2 feet while eliminating the double post/hallway effect.  To prevent issues with my stove pipe having to battle snow, I will follow the examples of cabins in my area - exit the roof at the peak (another (maybe poor) reason I didn't do ridge beam).  Suggestions on placement of the wood stove?  I'm thinking on the end of the kitchen bar rather than next to the refrigerator, the next post to the right.

I would like (but not a necessity) to have eaves in the long walls (top and bottom in drawing) - so I'm open to suggestions other than what I've stated above (principle rafter/purlin system), which is based on no experience.

Jim,
For calculating the weight on the purlins/principal rafters, do I divide the actual roof area supported by 1.414 (45°)?

[Brian_Weekley]

You've got that big 12x32 space.  Are you sure you wouldn't want to put a fixed staircase in--possibly in that lower right corner next to the bedroom closet?  It could be an "L" in the corner and wouldn't take much space.  It could double up (down to the basement and up to the loft).  Seems it would be much nicer than pull down stairs.  Also, you could take out the "hallway" and make your bedrooms larger.  Just a thought.

[Jim_Rogers]

Jim,
For calculating the weight on the purlins/principal rafters, do I divide the actual roof area supported by 1.414 (45°)?

I haven't done a lot of designing using a principal rafter, purlin roof system as I am a traditionalist and usually use common rafter roof systems.

I'd have to do some research on that.

When I figure roof load, I figure for total load applied vertically:



And when my beam or rafter sizes have been checked by one of my engineers; they have told me that they are the right size. Not too big and not too small.

A couple of years ago, I wrote up a story about how to review a frame design.
It is here: https://forestryforum.com/board/index.php/topic,50714.0.html

Have you seen or read this story?

I didn't use any modifiers in my calculations, but maybe I should have.

I took one class at Heartwood school on timber frame engineering. I'll have to review my book and see if there is a modifier for roof purlins mentioned.
I don't actually right now recall any being used.

This is why I hire engineers to review my frame designs to ensure that I have the beam sizes correct.

Jim Rogers

[Ljohnsaw]

Jim,
I had not seen that thread and I will read it later today - thanks. Your drawing above just puts my words/thoughts in picture form. The loads are all vertical so roof area needs to be calculated as vertical vector. I need to pull out my Statics book I used in school 34 years ago.   :P

[Ljohnsaw]

Ok, Jim. I read through that thread - very interesting and I totally get the math. However, I'm just a bit confused on your use of the timber calculator.

The first item is minor - I read somewhere that the a timber USED as a beam/stinger should have dimensions of AT LEAST 2" difference. In that post, you stated it should be MORE THAN 2". Not that big of a deal but you use that in your decision on using the calculator.

That is the more confusing to me. I see the definition of Post and Timber (P+T) as a vertical element and Beam and Stringer (B+S) as a horizontal-ish member.

P+T would be less concerned about deflection along its length and more about compression down the grain. B+S would be the opposite.

Unless I really read the thread incorrectly, it seemed that the 12x13 beam was being evaluated under the P+T criteria.  Is that really how it is supposed to be used?

Then again, does it change the answer when you flop the wood type (B+S:P+T) from one to the other?  I'll have to try it tonight.

[Jim_Rogers]

The first item is minor - I read somewhere that the a timber USED as a beam/stinger should have dimensions of AT LEAST 2" difference. In that post, you stated it should be MORE THAN 2". Not that big of a deal but you use that in your decision on using the calculator.

From my grade rule book, published by NeLMA; Section 6, paragraph 25.0 Beams and stringers (70.00 WWPA) 5" and thicker, width more than 2" greater than thickness.  end quote.

To me that say more than 2" greater, so 2" greater isn't a Beam and Stringer. It is a post and timber. If it was 2 and 1/8" then it would be greater. But 2" to me is a post and timber category.

That is the more confusing to me. I see the definition of Post and Timber (P+T) as a vertical element and Beam and Stringer (B+S) as a horizontal-ish member.

Right, if the timber is greater in height/width then thickness then it is assumed that the user will place it horizontally or on an angle like a stair stringer, such as rafters.

P+T would be less concerned about deflection along its length and more about compression down the grain. B+S would be the opposite.

Right.

Unless I really read the thread incorrectly, it seemed that the 12x13 beam was being evaluated under the P+T criteria.  Is that really how it is supposed to be used?

If that thread says it's a 12x13 then it's in the P+T category, whether or not if it's used vertically or horizontally.

Then again, does it change the answer when you flop the wood type (B+S:P+T) from one to the other?

It may pass in one category but fail in another due to design values being different.

I hope that helps you some.

Jim Rogers

[Ljohnsaw]

Jim,
It does help, those are the rules. However, in my engineering mind, when I see something horizontal, you need to evaluate it as a horiontal member. Without knowing what the mechanics are behind Don P's calculators, my mind will be forever in unrest! I had the same problem in sadistics Statistics - they would say, just do it this way. Calculus I got.   I need to play with it, do some further research to put my mind at ease. I want to be able to be 100% confident (able to describe how I came up with the values) when I talk with the engineer that will be reviewing my building plans.
Thank you

[Jim_Rogers]

When I first discussed my designs to be reviewed by one of my engineer's, I asked if he wanted me to show him my "work". That is how I came up with the numbers I used.

He said it was his job to come up with the numbers and not just read my work.

That way he'd be satisfied that the numbers are correct.

When you have your design done, and you're ready to go to your engineer, if you need any further information then let me know and I'll help you with all the data I can to give to him.

He should be using the NDS values which are what's in DonP's calculators.

I have the book and use that as well as the online calculator.

Maybe tomorrow, I can tell you about DonP's calculators and my work with him.

Going home now after a very cold day outside at the mill.

Jim Rogers

[Ljohnsaw]

More information was volunteered by the planning department (a plan examiner) which make the design easier (less decisions for me because of the requirements):

For Heavy Timber construction, they have a whole section on construction criteria.  Some seems a little oddly worded (asking them for clarification) and seemingly excessive but not too burdensome requirements.

Ex:

602.4.2 Floor framing – States that beams & girders need to be no less than 6x10.  No mention of joists – filling in the spaces between the girts to a reasonable span for the floor boards.

602.4.3 Roof framing – in the center of the paragraph, it states the "other roof framing, which do not support floor loads, shall have members not less than 4 inches in width and not less than 6 inches in depth".  I'm assuming that is referring to purlins and/or common rafters.

602.4.4 Floors – Need a subfloor of at least 3" thick nominal (2-1/2") T&G boards and the 1" finish floor (3/4")  Regardless of the joist spacing?  That's a lot of floor!  Since it looks like I will have to do a sub-floor, I can run the "joists" the short way from bent to bent, which may be at a minimum, 6x10s.

602.4.6 Partitions – ...not less than two layers of 1-inch matched boards...  What are "matched" boards?  Can anyone comment on what they had to do for interior walls in a permitted structure?  I think what I may do is for the bedroom walls where visible to the common room is to place the purlins on the main room surface so it matches the exterior walls in appearance.  I guess I cannot have a "plumbing" wall between my kitchen and bathroom!  The shower pluming will be "hidden" behind the refrigerator!

Other parts mention the outside wall cannot have any open cavities, that is, no stud walls, which is not a problem for me.

[swampfox]

You guys are thorough.  And its well thought out.

Here is a picture that might help with the conversation:



In my opinion there are too many bents.  If I might add a suggestion.

• I would delete B and F.
• Move C towards A on the other side of the bar.  This should get you to around 14'.
• Establish a ridge
• Entertain the idea of principal purlins with light commons on top

I don't know what your post x-sections are, but if you have to resize the whole frame a little larger but with less bents.

Just food for thought.

[Ljohnsaw]

I drew the plans up in Sketchup. How do you add decent looking text?  I could not do it very well. I have a ton of new information and will be re-working my ideas. I already removed B and F and changed the center two posts into one except at A, E and G per Jim's suggestion.  As far as bent spacing, the snow loads are such that at a 12' spacing with purlins spaced at 2', the purlins are required to be 6x9s. If I push out to 14', they will need to be even bigger. I'm using Ponderosa pine - no hardwoods available. Stay tuned - I will detail my sizing of wood calcs soon.

[fountain]

I have Photoshop. ;)

No doubt you two will figure this out.  Just keep in mind that your purlins don't have to flush out with the top of the principal rafter.



Cheers.  I look forward to this thread.  Good one.

[swampfox]

 ^^^^

:D I have two accounts!  Accidently logged in with new one.  Then I remembered my password..

[Ljohnsaw]

I'll have to think about doing the purlin "proud" of the rafter.

OK, here goes, please correct me (Jim) if I have this wrong -

The cabin will be 26' wide by 49'-4" long.  In the view below (without the purlins) you can see I'm going for a queen post design to help split the principle rafter span in two. 


I have not calculated the tie beam size at this time.

The particulars for my location:

Dead load on roof - 30 psf, Ground Snow Load - 303psf with a calculated 116 psf RSL (Roof Snow Load) on my 12/12 sloped metal roof with no obstructions in a clear area.

The bays are four 8' and one 12'.  The roof planks (and walls) will be 2" T&G Incense Cedar which has a weight of 4lb/bd-ft (as does the Ponderosa Pine to be used for purlins and rafters/beams).  The purlins will be spaced at 2' on the slope.  The calculations for the purlins - the roof area in question will be 24 sq-ft actual and 16.97 projected (for snow and live load).

To calculate the purlin, I need the purlin weight (guess at 6x9) for the biggest bay (12') and it is 216lbs.  The wood planking is 48 sq-ft and comes to 192lbs with a total dead load of 408.  The live load of 30psf on the 16.97 is 509lbs and the snow load comes to 1,969.

Plugging in the beam calculator:

Total load on Beam (purlin) - 2,377 lbs
Dead Load on Beam          - 408
Span of Beam (inches)      - 144
Width of Beam                 -  6
Depth of Beam                 -  9
Select Species and Grade  - #2 Ponderosa Pine B+S

This gives me a pass on all three.  The Section Modulus Required is 71 and I hit 81, the deflection is just under 1/4", and the section required for shear is 13.7 and I hit 54.  The bending was the big problem.

For the principle rafter, normally it would carry the load of 1/2 of each adjoining bay.  But with the queen posts, I'm dropping the load in half.  So, 1/4 of the area of the 12' bay:

Dead load of 408 x 6 (purlins for entire rafter) / 2 (half the bay) / 2 (half the rafter) = 612lb.

Total load (from 12' bay) is 2,377 x 6 / 2 / 2 = 3,565lbs

Doing the 8' bay, Dead load of 272 x 6 / 2 / 2 = 408lbs

Total load 1,585 x 6 / 2 / 2 = 2,377lbs.

Add to both dead and total loads the weight of the (1/2) rafter = 192lbs.

Grand total dead load is 1,212 and grand total total weight is 6,134lbs

Plugging in the beam calculator:

Total load on Beam (rafter) - 6,300 lbs (rounded up)
Dead Load on Beam           - 1,400 lbs (rounded up)
Span of Beam (inches)       - 72
Width of Beam                  -  8
Depth of Beam                  -  12
Select Species and Grade    - #2 Ponderosa Pine B+S

This gives me a pass on all three.  The Section Modulus Required is 94.5 and I hit 192, the deflection is just about zero, and the section required for shear is 36.4 and I hit 96.

Since this is way over-kill, I could drop down to 7x10 but I'm worried I would not have enough meat to plug the purlins into it.

Thoughts and comments welcome.

[Jim_Rogers]

If you are entering a dead load then remove it from the live load. You're adding it twice, I think.

Live load is your snow load only.

Dead load is all your roofing materials, and the timbers themselves.

You may need to "run" your numbers again.

When you have the calculator open, you can select "save as" and put it onto your own home computer so that you don't have to be online at the forum to use it.
For your information.

I don't have any weight values on Ponderosa pine so I'm not sure if that is correct or not. I'll assume you have done your research and that they are correct.

As far as I can see other then the double counting the dead load, your process looks right.

Jim Rogers

[Ljohnsaw]

If you are entering a dead load then remove it from the live load. You're adding it twice, I think.

Live load is your snow load only.

Plus the 30psf required by the county?

Dead load is all your roofing materials, and the timbers themselves.

Maybe I need clarification on the calculator.  What is the "Total Load on Beam", first box - is that just the Live Load (30psf + the snow load)?  I take things too literally.  To me, Total means total.

You may need to "run" your numbers again.

When you have the calculator open, you can select "save as" and put it onto your own home computer so that you don't have to be online at the forum to use it.
For your information.

I don't have any weight values on Ponderosa pine so I'm not sure if that is correct or not. I'll assume you have done your research and that they are correct.

As far as I can see other then the double counting the dead load, your process looks right.

Jim Rogers

Thanks, Jim - I anxiously await your response. 

Also, I messed up a little on the dead load.  The purlin sections I stated 6 for the span.  In plan view yes, 2' on center, but for 2' on center on the roof slope, I need 41% more (2.47 more purlins, so round to 3).  My dead load on the roof area for the rafters goes up a little.

[Jim_Rogers]

John:
If you use the first calculator for uniformly loaded beams, now that you know the values for grade #2 ponderosa pine, you would enter the total load on the beam.

I don't know why DonP added the dead load factor in the second calculator.

But, if you understand that the gravity load is vertical, and the dead load is in the slope of the roof plane, (which means it is higher then if the roof was level) you can add to the live load the adjusted dead load to get one number; which would be the total load. And then use the first calculator that asks for one load only. Then you won't be double dipping, and over sizing your timbers.

Jim Rogers