Thread: How would you support this roof and ceiling?

What size framing members would you use and where would you add supports while keeping material cost as low as possible? The location is lower Michigan so snow loads need to be considered.


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I would us the size that the licensed architect or licensed engineer specified.

Really.

My Architect told me an experienced builder would be able to figure it out with ease.

Originally Posted by Goldie Flagler

My Architect told me an experienced builder would be able to figure it out with ease.

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See you answered your own question.
*contact your Architect or Licensed Contractor of your choice.
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Originally Posted by Goldie Flagler

My Architect told me an experienced builder would be able to figure it out with ease.

Is there a reason why your architect will not tell you?

Why are there no dimensions on your drawing? How long are those rafters? If you are concerned about snow load, why are the 24" on center?

You really should get a qualified architect to design and specify this project. Many time, great ideas (and pretty pictures) can turn into nightmares.

Originally Posted by Goldie Flagler

What size framing members would you use and where would you add supports while keeping material cost as low as possible? The location is lower Michigan so snow loads need to be considered.

Fact is the city is going to want sized lumber and dimensions and an architect if not engineers stamp. Could most of us walk in and figure lumber after looking at the site and drawings, sure. That is not going to do you one bit of good. Permit equals stamped engineers drawings or architectural drawings at the minimum.

And at snow load Michigan area 16 on center is the only way to go. Either that or larger framing members and 3/4 T+G OSB or 3/4 T+G plywood

The idea of keeping material costs low should be one of your last considerations. You need to think what is safe and energy efficient first. You go 24" center and you'll have a problem somewhere down the road, also if you go less than 3/4" plywood. Don't let them sell ya on OSB either. Its your home, don't cheat your investment.

Originally Posted by Goldie Flagler

My Architect told me an experienced builder would be able to figure it out with ease.

And the experience builder would ... at a cost as he would be in charge of the entire job and would get his cut, and thus he would be able to cover his liability for designing it based on the code.

Then again, the only reason I can figure that an architect did not want to design it would be because you did not want to pay them for their time, expertise, and have them be able to cover their liability.

I gather the above two presumptions from your desire of "while keeping material cost as low as possible".

Sounds to me like you do not want to pay for someone to do the design work, and the design work comes with some liability, and the person doing the design work will need to cover their liability.

Would you mind giving us the reason the architect did not want to do the design and instead told you "an experienced builder would be able to figure it out with ease"? Thank you.

This is a perfect example of why this forum should go back to "Inspectors Only", and drop the Homeowner DIY section.

Stephen:
Thank-you so much for your multiple comments,
Roof rafters: The maximum span between bearing points for any of the common rafters = 12'6"
Hips: maximum span between bearing points (both are the same length) = 20'
Ceiling Joists: maximum span between bearing points: 12' span

The architect:
Not sure why she would not give data or said what she did, she said she has always worked this way, She has been doing multi million dollar homes in this area for at least 2 decades, of course they are built to code, but I can not vouch for how they are holding up/the structural integrity.

I still need to solve for loading effects of the "floating" ends of the flat ceiling portions in the partial cathedral that will "hang" off the jack rafters and make sure the the valley rafter is strong/supported enough.

Stephen, Ted, David, and Jerry,
Thank you for your straightforward comments and taking the time to read and share your thoughts and insight. I imagine you guys have seen it all, the good, the bad, and the ugly.

By the way, the shack being remodeled was orignally built with a 1.5" pitch roof with 2x4 ceiling members 4' O.C. over 12' spans in the 50's. While nothing has fractured, I have a pretty good understanding of deflection and this remodel will certainly not be under constructed.

Hi Jack,

I hope you are doing well.

I look forward to seeing you in a few days at the inspection conference.

I respect you opinion however there have been so many DIY questions I felt it appropriate to create a DIY section (at the suggestion of another member) so that the questions would not interfere in the inspector to inspector conversations on the rest of the board. I think that has worked out well, a specific question just for DIY.

If anyone is not interested in any specific category/section on the board then just do not go into those sections.

Also, sometimes a DIY question is posted in the other sections of the board. If anyone spots those please click "Report" and let me know so I can move it to the appropriate section.

See you soon!

Originally Posted by Goldie Flagler

Stephen:
Thank-you so much for your multiple comments,
Roof rafters: The maximum span between bearing points for any of the common rafters = 12'6"
Hips: maximum span between bearing points (both are the same length) = 20'
Ceiling Joists: maximum span between bearing points: 12' span

The architect:
Not sure why she would not give data or said what she did, she said she has always worked this way, She has been doing multi million dollar homes in this area for at least 2 decades, of course they are built to code, but I can not vouch for how they are holding up/the structural integrity.

I still need to solve for loading effects of the "floating" ends of the flat ceiling portions in the partial cathedral that will "hang" off the jack rafters and make sure the the valley rafter is strong/supported enough.

Stephen, Ted, David, and Jerry,
Thank you for your straightforward comments and taking the time to read and share your thoughts and insight. I imagine you guys have seen it all, the good, the bad, and the ugly.

By the way, the shack being remodeled was orignally built with a 1.5" pitch roof with 2x4 ceiling members 4' O.C. over 12' spans in the 50's. While nothing has fractured, I have a pretty good understanding of deflection and this remodel will certainly not be under constructed.

Goldie,

Get a new architect.

The only thing you should have to solve is paying for the project.

My guess on architect is that she works with a computer program that she has no reliability on material sizing to meet local codes. In addition to not being able to do the math herself.

Many people draw up a design and then cop out and leave the liability for errors to some one else. Thus when there is a problem their hands are clean.

One other thought is that it is not uncommon for a truss manufacture to do the take off of a drawing and they would calculate the actual loads and design for the job site location.

So, try taking your design to a truss fabricator or a material supplier (who will send out to fabricator) for a quote on price. Quote will give you design and materials used.

Goldie,

Its the architects job to work with a structural engineers to create the specifics for the job. Builders then build to the plans. When the architect is specific enough there is the possibility that a substandard structure will be built. Many contractors will use the cheapest fastest method to build the addition and the only way they can be called on it is by the city or referring to the build plan.... I have a client right now that going through that exercise.

With that said most truss companies will take plans and create trusses for the build. Today that is the easiest way to throw up a roof system.


//Rick

Originally Posted by Garry Sorrells

My guess on architect is that she works with a computer program that she has no reliability on material sizing to meet local codes. In addition to not being able to do the math herself.

Many people draw up a design and then cop out and leave the liability for errors to some one else. Thus when there is a problem their hands are clean.

An architect would use an ACAD program, which requires dimensions.
In my opinion although the picture is computer generated, it is home made .

Actually, the picture is strictly conceptual, and not for building.

Drawing is to scale but lacks dimensions.
All lumber must be grade 1 or 2 SPF or better and no southern SPF
Hips and Ridge 2 x 10
Hip Jacks 2 x 8
Flat ceiling members-center section-bearing both ends(drywall nailers) 2 x 6
Flat ceiling members-end sections bearing only on one end TBD and load effect on hip jacks TBD
Valley needs to be doubled and supported with struts

Goldie,
Are you going to build this by yourself (lead carpenter) or will you have others working for you?

Hi Gary-
A builder will do the framing. Also thanks for your advice on the truss engineering, I am going to try it as well. The lumber sizes I posted are from the builder who seemed confident and has a long relationship with the local building inspector.

Originally Posted by Goldie Flagler

Hi Gary-
A builder will do the framing. Also thanks for your advice on the truss engineering, I am going to try it as well. The lumber sizes I posted are from the builder who seemed confident and has a long relationship with the local building inspector.

So, I have to ask these question.

Why if you have a builder, why did you post your question on this forum ?
Do you not trust your builder on keeping the cost at a minimum ?
You do not trust the builder on proper design specifications ?

Originally Posted by Garry Sorrells

So, I have to ask these question.

Why if you have a builder, why did you post your question on this forum ?
Do you not trust your builder on keeping the cost at a minimum ?
You do not trust the builder on proper design specifications ?

I get 2nd and sometimes even 3rd opinions on any large expenditure...Trust but verify.

I posted on this particular forum because I was interested in an alternate viewpoint and figured that someone here might after years of looking at buildings be able to simply respond with an opinion only of what might work.

I would also be concerned about the connection to the house.
Snow drift off the original roof could put an enormous snow load on the new framing. Talk to the arch and builder about snow drifts.