[WHBIII]

How do I attach a new pitched roof to my existing roof ? What data do i need to even need to begin to plan this out? How do I determine the pitch of the existing roof so as to match the new roof addition to the same slope? Area to cover is 15 x 15 , single story house. I want the eve/edge of the new roof to match up with the eve/edge of the existing roof. The house is 20yrs old if that makes any difference. The cover will be open , no walls.

 

[12penny]

...a couple pictures and a drawing of the proposed new roof will do wonders getting you numerous, expert opinions.

 

[WHBIII]

I attached three photos.

 

[bob22]

Is this a one or two-story home? To the right, left, or across the chimney? A bit too vague in describing your goals.

 

[Ron6519]

How do I attach a new pitched roof to my existing roof ? What data do i need to even need to begin to plan this out? How do I determine the pitch of the existing roof so as to match the new roof addition to the same slope? Area to cover is 15 x 15 , single story house. I want the eve/edge of the new roof to match up with the eve/edge of the existing roof. The house is 20yrs old if that makes any difference. The cover will be open , no walls.

If you're extending the current roof line down from the current fascia, this won't work if the roof is one story. As you extend the roof line it gets closer to the ground. By the time you get out 15 feet the roof will be hitting the ground. If the fascia is 10 feet off the ground and your roof pitch is 12 in 12, the roof will hit the ground in 10 feet.
If you want to extend the roof from the fascia board, the roof will be nearly flat going out 15 feet.
To get more slope, you would need to start the patio roof up onto the house.
In either case, the roof lines would not match.
Ron

 

[WHBIII]

I want to have the new roof pitched like the existing roof. Not a flat lean too type. Any thoughts on that design?

 

[WHBIII]

It is a single story house. And I want to have it pitched and centered on the fireplace coming out over the patio. Which means I assume part of this will have to be built around the chimney? To keep the roof lines at the same height how high would the structure need to be? Say the current roof line/edge is 8ft to 9ft off the ground.

 

[sixeightten]

So it will run perpendicular to the existing? If so, that is a very common design. Generally, we would match up the beam height with the existing wall height and then calculate rafters off of that. To determine your existing slope, you can use a 4'level to see what the difference is in 4'. Lets say the difference in 4' is 24". This would equate to 6" per foot, or as we would say, a 6/12 pitch.

 

[sixeightten]

Ask some friends for a reccommendation of a Contractor or carpenter to at least get you started. This is a bit more than a weekend warrior job for a serious DIY'er. The existing roof can remain, with new framing extending over, but the shingles will need to be tied in carefully.