Converting Shed roof to gable?

[Nate R]

My house has a 80 year old addition on the front and the roof is sagging.

We're thinking of maybe replacing it with a gable roof. Some tiny trusses or rafters, not sure yet which.

Anyone done this?

Is my city going to require an engineer to sign off on it, or just inspection to make sure I use the correct size rafters, connectors, insulation, etc? Or do they want complete engineering inspection from foundation to roofline typically?

Calling my city's development center tomorrow for guidance on permits, etc, but I figured I'd throw it out here to see if anyone has done something similar to see what they had to go through, suggestions, tips, etc.

Old pic from when we bought the house, but it shows what I want to do.
Doing it for the increased ceiling height inside and exterior aesthetics. Since it's sagging, I'll have to do SOMETHING with it anyway. It's only a 9 foot span, but 2X4s aren't appropriate for that as someone must've thought would be OK.

[loafer]

You shouldn't need engineering involved for this, just a building permit. Find out what the appropriate snow load is for your region and then use the span tables to size your rafters. In my region (S. Maine) 2x6s on 16” centers would be sufficient. Code enforcement will want to see propper venting as well.

[hj]

Trusses would be engineered for the span and load, but, I see a couple of potential problems with your design.
1. Having the new roof at a different "angle" than the old one will create an odd appearance.
2. Installing the new roof with the same pitch as the old one might create a conflict with the upstairs window over it.

These issues might be enough for the building department to ask for an architect's design.

[Nate R]

We were thinking 8/12 probably wouldn't look too weird, and would *just* clear the window upstairs. (Original roof is 12/12) I'm still not sure that it would look OK, though. Trying to find a solution where the addition doesn't looked so much like a tacked on afterthought as it does now. I'm open to suggestions.

The entire exterior will be redone in the future, so I don't care how it looks now, and don't have to worry about blending siding, etc. (New soffits, fascia, window wrap or trim, windows, siding.)


Talked to the city development center on the phone today. They said that if it was pretty straightforward, something that was quite standard by today's codes, they'd be fine with no engineering. But if there was anything odd about it like a huge span or something, it would require an engineer's input. They can't tell me for sure until a plan examiner sees what I want to do.

Trusses would be engineered for the span and load, but, I see a couple of potential problems with your design.
1. Having the new roof at a different "angle" than the old one will create an odd appearance.
2. Installing the new roof with the same pitch as the old one might create a conflict with the upstairs window over it.

These issues might be enough for the building department to ask for an architect's design.

[Nate R]

Trusses would be engineered for the span and load, but, I see a couple of potential problems with your design.

2. Installing the new roof with the same pitch as the old one might create a conflict with the upstairs window over it.

Hmmm.... Suppose the easy solution is to put in a shorter window.
Might be able to move the current window up a bit, too. Either way, that would mean it wouldn't match the other windows in the dormer. Hmmm.

As you said, I'm sure an architect or engineer would have to get involved then. Which I'll do if I have to.

[hj]

The ONLY way not to have it look like an afterthough is for its roof to become an extension of the main roof, using the same pitch, shingles and everything. That "odd" gap between the two would be a dead giveaway, since it would NEVER be done with an original installation.

[frenchie]

Match the pitch of those dormers? Except I think they're not even at the same pitch, are they?

I think the shed roof would be fine, if it wasn't sagging. No need to match pitch, or roof types, it's an add-on. Nothing wrong with an add on looking like an add-on.

...Might look a bit smarter of the ends had a return, like half a hip roof, the way you'd do a bay window.

[loafer]

Match the pitch of those dormers? Except I think they're not even at the same pitch, are they?

I think the shed roof would be fine, if it wasn't sagging. No need to match pitch, or roof types, it's an add-on. Nothing wrong with an add on looking like an add-on.

...Might look a bit smarter of the ends had a return, like half a hip roof, the way you'd do a bay window.

I like the hip roof idea.

[Mike50]

The ONLY way not to have it look like an afterthough is for its roof to become an extension of the main roof, using the same pitch, shingles and everything. That "odd" gap between the two would be a dead giveaway, since it would NEVER be done with an original installation.

Absolutely correct and I'll go one step further. Maybe you have to have an eye for graphic design to see that If he doesn't duplicate the design--it will look awful-like a christmas bonus project. If you cant do it--then leave it as is imnsho. ALL trim will need to be re painted.