Check awc.org for lumber span calculator. Simply, floors need more capacity than roof, so for 10', 2x8 will be more than enough. Check ground snow load for your area. I mention floor but there are calculators and charts for rafters too.

 

Simply, floors need more capacity than roof,

Not all places, especially in Canada. There are areas where the snow load exceeds residential floor loading.

Start with the locally applicable snow load, then find a span table that shows joist sizes for roofs with that snow load.

 

Does 10 ft high put you below the eves of the garage.
I would remove stucco for the ledge,
Notch and lap both members of the beam at the posts.

 

Does 10 ft high put you below the eves of the garage.
I would remove stucco for the ledge,
Notch and lap both members of the beam at the posts.

It will be on the gable end of the garage.

I read one suggestion is to cut 1" deep into the stucco and push the flashing into that gap. I plan to have a metal roof.

 

I believe you should start with your local AHJ and find out what your loading's are locally.

Where I built I had a wind load of 108mph and a design temp of 28f-109f.

Choosing structure not knowing what is going up there, even the once in a life time storm, your just being short sighted.

 

Will this help?

Span Tables - Calculate Joist, Rafter and Wood Beam Spans

Span Tables - Use these tables to determine rafter span, ceiling joist span, and floor joist span

www.mycarpentry.com

 

Cutting into the stucco 1" will only work if it is more than 1" thick. I am assuming the wall behind is wood? If possible I would use lead flashing mortared into the cut, it is a lot easier to mold around things that may stick out a little.

 

What about when you want dry inside the addition, water does drain out the bottom, thru the weep screed.

 

You aren't going to get an overhead door to fit with the low top plate at 8 ft.

 

7 ft high door.

 

Thanks guys I checked my local codes. It's 30 psf for snow loads. So I can use a 2x6 SPF 24” centers and span up to 11’ 2”

 

I would check that table again, or maybe look at a different table. The allowable bending stress for the highest grade of SPF lumber (select structural) is 1250 psi, with construction grade at 1000 psi, and stud grade at 675 psi. My numbers say that you'd be at almost 1500 psi bending stress in the rafters for just the 30psf snow load, without any dead load or factor of safety. Your roof may be light, but it will weigh something, and you're unlikely to find even construction grade lumber at a big box store.

 

Are you sure that is all? I'm in nj and that's my snow load. Once in a blue moon, snow piles up and turns into ice. For safety, I would not take the average numbers of the area. I tend to over-build.

 

This is from my code book. So should I use rafter or joist spans chart? thanks.

 

I got curious. Also didn't know where manitoba was. Googled there and snow loads are in kpa? So went to nearest us town, belcourt, north dakota and the snow load there is 60 psf. I may be wrong about your location but you may want to verify again and again.

 

Yeah, Manitoba is North of North Dakota. I'm about 2 hours North of Grand Forks, North Dakota.

Everything that I can find says our code is 30-psf (in most areas of Canada actually) for a roof and 40-psf for a floor.

I will be sure it have it all double checked by a professional.

 

Would this be the proper way to do the horizontal rafter support carrier(s)? One on each side of the post?

My other thought was to notch the post on the outside and set one carrier in the notch and then attach a second carrier to the outside.

I'll also use the hurricane hangers.

 

Can you post a picture of the garage so we can see the roof?

 

This is the connection, post to the beam.

 

So a 6x6 post notched half way and both beams sit on it. Thanks.

 

Will it look similar to this ?

 

Will it look similar to this ?
View attachment 689327

Yes.

 

Attached is 2 pages of what I think is my final design before I take it in to have verified. Minus some small details like the end walls.

Due to the low roof pitch I treated it as a deck and followed those codes. Deck codes are for 40 psf where as the roof codes are for 30 psf. So everything has been fortified.

 

 

See attached. It can't be moved to the center due to property constraints.