Oy, No ridge beem!

[THOMLEP]

Hey Everybody,

I'm sticking a 10ft long shed dormer on the back of my 1940s cape. The roof is supported by a knee wall 6 feet in from the walls. Under the domer the knee wall will be removed to make space for a bathroom. All the plans I've see for a shed dormer indicate an existing ridge beam that contributes to supporting the whole roof. The big problem here is there's no ridge beam!

Can anybody provide some pointers to shed dormer construction when there is no ridge beam? I'd like to avoid placing roof-supporting beams down through the center of the house.

Thanks in advance for any ideas or references.

-Tom

[Sweep]

At 10 ft it will need a ridge beam unless there is something else holding up the other side of the roof.

[Joe Carola]

Hey Everybody,

I'm sticking a 10ft long shed dormer on the back of my 1940s cape. The roof is supported by a knee wall 6 feet in from the walls. Under the domer the knee wall will be removed to make space for a bathroom. All the plans I've see for a shed dormer indicate an existing ridge beam that contributes to supporting the whole roof. The big problem here is there's no ridge beam!

Can anybody provide some pointers to shed dormer construction when there is no ridge beam? I'd like to avoid placing roof-supporting beams down through the center of the house.

Thanks in advance for any ideas or references.

-Tom

There's no ridge there at all? Are the rafters nailed right into each other?

Or are you talking about a Structural Ridge Beam?

Will there be ceiling joists or will it be cathedral and you will be sheetrocking the bottom of the shed rafters?

If you’re putting in ceiling joists and there's no ridge there now, you don't need a Structural Ridge Beam. You can just add a ridge to the rafters.

What is the height of the outside dormer wall that the shed rafters will be sitting on? Also, what is the height to the top of the rafters?

[THOMLEP]

Hello Joe. Thanks for responding. I put the answers to your questions below.

>There's no ridge there at all? Are the rafters nailed right into each other?

There's no ridge beam. The rafters meet at the crown and are probably nailed together

>Or are you talking about a Structural Ridge Beam?

I don't know. I'll need to add a ridge beam along the width of the dormer.


>Will there be ceiling joists or will it be cathedral and you will be sheetrocking >the bottom of the shed rafters?

I'd like it to be cathedral, with a skylight, if possible. Also to keep the ceiling as high as possible.

>If you’re putting in ceiling joists and there's no ridge there now, you don't >need a Structural Ridge Beam. You can just add a ridge to the rafters.

So, if the dormer is 10ft wide, the new ridge beam should run that 10ft? Currently one side of the roof is supported by the other side of the roof. When rafters are removed from one side, the other side won't have support until I get that ridge beam and new sistered dormer-end rafters in place. Is that right?

>What is the height of the outside dormer wall that the shed rafters will be >sitting on? Also, what is the height to the top of the rafters?

No dimensions drawn yet. The outside wall, facing the back of the house, will be pretty low, maybe 4.5 ft. It won't have a flat roof, but be something like
12/4 pitch.

The top of the shed rafters will meet at the peak of the roof at about 9 ft higher than the second floor.


-Tom