Roof line for Extension on garage

[diybiker]

Hi All
I am building an extension on my garage. My existing garage is 28 by 28 and the extension is 26 by 16. Therefore, I need 9 truss on 2' center. My question is: should the truss be 28' in length to bypass the existing wall or should it come flush with the existing wall. Also, for the roof, is there something special that will need to go against the existing wall where the roof meets it.

Thanks in advance.

P.S. This is in Canada, not sure if this makes a difference.:confused:

[Richard A Hetzel]

A complete picture isn't possible from your description. If you can post a sketch or drawing of some kind, or even photos of the existing house, it may help us to be able to help you.

[Joe Carola]

Hi All
I am building an extension on my garage. My existing garage is 28 by 28 and the extension is 26 by 16. Therefore, I need 9 truss on 2' center. My question is: should the truss be 28' in length to bypass the existing wall or should it come flush with the existing wall. Also, for the roof, is there something special that will need to go against the existing wall where the roof meets it.

Thanks in advance.

P.S. This is in Canada, not sure if this makes a difference.:confused:

Are you talking about something like this?

[Don_P]

Oh, I thought it dropped down and in, under the fascia and overhang of the existing.

[diybiker]

I was thinking of attaching it under the existing roof thinking that it might be easier.

[Don_P]

That's what I would do. Trying to plane in almost always shows. I think I'd order tails giving the same overhang as the original and just do a return where it projects by the wall.

You do need to remove, flash and replace siding if you drop that far. At the minimum end I've dropped just under the existing fascia, step shingled up it and then counterflashed with a colored strip of metal tucked under the drip edge and over the step flashings.

[Joe Carola]

I was thinking of attaching it under the existing roof thinking that it might be easier.

Is this what you're talking about? If so, you just have to drop the wall height of the new addition.

[fcastro]

diybiker sorry off topic but was wondering what software did you use to make that sketch? Looks nice!

[diybiker]

fcastro, sorry but I cannot take the credit for the drawings. I think that it is Joe Carola.
But I agree, it seems to be a great software. Also, thanks for all the replies, I think that I can do this now.
Again, thanks

[Don_P]

Check out Google Sketchup, its a free download, quick and easy to learn, a great program, and the price is right.

[Raynar]

How high above a roof line should a chimney extend?
I am installing a 96,000 BTU woodstove and am wondering how high above the roof line should the chimney extend..I have heard 2 to 3 feet for proper draft...

[Richard A Hetzel]

The rule of thumb is two feet above anything that is within 10 feet of the chimney, But, rules of thumb only get you so far...for example, if the chimney will be on a building that's at the bottom of a steep hill, or next to a taller building,there may be downdraft issues, and a higher extension plus a chimney cap may be necessary. The rule of thumb seems to work in 99% of the cases, though.

[carlsguide]

That Google Sketchup is great. Thanks for the info.