Ridge and rafter issues/shed dormer

[Adam_J.Deangelo]

am new to this site and just wanted to get a couple of opinions. I recently framed a shed dormer onto my cape cod style house. The dormer wall spans 28’ in length & 6’9" high, with the overall length of the house 32’. I recently finished and have to get an inspection. There are two issues I think the inspector may have. I want to see if these will be issues and what I can do about them before the inspector comes.

1. The ridge size. The existing roof, an 8 pitch, was framed with 2x6’s and no ridge board. The rafters on the shed dormer, which is a 3 pitch, are 2x10’s. I used a 2x6 as the ridge board. The 2x10’s hang below the board about 4 inches. The 2x6 portion of the roofs hangs below the ridge about 2 inches. I did not specify a ridge size in my submitted plans. My question is will this be a problem. If so, can I slide a second 2x6 between the rafters to compensate?

2. The rafters of the shed dormer are offset from the original rafters. I framed the dormer wall at 16" centers. However, I neglected to line the wall studs up with the existing 2x6 rafters on the other side. As a result, once the wall was lifted the wall studes did not line up with the existing rafters. I chose to put the dormer rafters over the wall studs and offset them from the original 2x6 rafters, rather than line the rafters up and have them offset from the wall studs.

Just wanted to get an opinion on these two issues. A couple of additional facts- There are 2x6 collar ties at 16" centers and a height of 8’. Since the rafters didn’t line up, I installed a nailing board the length of the existing roof and cut that end of the collar ties at an 8 pitch. The roof is a standing seam metal roof. I built this just before the winter and had about 3 inches of pure ice on the roof and have had no problems.

[dhelm (David E. Helm)]

When originally built, the houses rafters supported each other and did not require a ridge board. Adding a wide shed dormer removes this condition. It is likely that a structural ridge would be required. Was this project permitted, and did the plans examiner OK it?

[kshepard (Kenton Shepard, CMI)]

am new to this site and just wanted to get a couple of opinions. I recently framed a shed dormer onto my cape cod style house. The dormer wall spans 28’ in length & 6’9" high, with the overall length of the house 32’. I recently finished and have to get an inspection. There are two issues I think the inspector may have. I want to see if these will be issues and what I can do about them before the inspector comes.

1. The ridge size. The existing roof, an 8 pitch, was framed with 2x6’s and no ridge board. The rafters on the shed dormer, which is a 3 pitch, are 2x10’s. I used a 2x6 as the ridge board. The 2x10’s hang below the board about 4 inches. The 2x6 portion of the roofs hangs below the ridge about 2 inches. I did not specify a ridge size in my submitted plans. My question is will this be a problem. If so, can I slide a second 2x6 between the rafters to compensate?

Do you mean the dormer rafters span 28’ in length? Dormer walls are rake walls and have no set height, unless you mean the front wall of a shed dormer, which would be “wall” (singular) I don’t understand what ridge you’re building down. shed roofs have no ridge. If you mean a gable… yes, you can build down the ridge but typically the framing must be engineered if you’re pulling a permit, which engineering would include the ridge size.

2. The rafters of the shed dormer are offset from the original rafters. I framed the dormer wall at 16" centers. However, I neglected to line the wall studs up with the existing 2x6 rafters on the other side. As a result, once the wall was lifted the wall studes did not line up with the existing rafters. I chose to put the dormer rafters over the wall studs and offset them from the original 2x6 rafters, rather than line the rafters up and have them offset from the wall studs.

OK now I understand. If you installed a ledger on the original roof on which the tops of the shed rafters bear- no problem. If the shed roof rafters bear directly on plywood- problem.

Just wanted to get an opinion on these two issues. A couple of additional facts- There are 2x6 collar ties at 16" centers and a height of 8’. Since the rafters didn’t line up, I installed a nailing board the length of the existing roof and cut that end of the collar ties at an 8 pitch. The roof is a standing seam metal roof. I built this just before the winter and had about 3 inches of pure ice on the roof and have had no problems.

I still don’t understand this part. I assume you mean “rafter ties” since collar ties are installed in the upper third of a roof and would be at 8’ . You installed a nailing board where? For what? A shed roof requires no collar ties because the rafters are continuous over the span.