Loft Reconfiguration

[TRAK.Structural]

Working on a residential renovation project that involves some changes to an existing loft space. The home is a simple rectangle with gable roof that is stick framed so its not very complex. The owner wants to remove a portion of the loft floor framing to create an overlook from the loft down into the ground level. I'm thinking that is going to require adding a new structural ridge beam at the roof peak because cutting out parts of the loft floor joists removes the continuity of the tension tie for a traditional rafter/tie system. Am I thinking about this correctly or is there another way to make this work without a new ridge beam? See sketches below for existing and proposed changes.

 

[DoubleStud]

What are the floor joists for the loft? I can already see the homeowner is saying "That ridge beam is too low".

 

[XR250]

I think a struct. ridge is likely the only practical option. Why are you adding a beam at the kneewall? Rafters overspanned or spliced at the kneewall?

 

[Ron247]

The most common modification I know of is to install a ridge beam in place of the ridge board as you note. How far will this modification extend into the length of the house?

Interior walls that are parallel to the roof framing offer ties periodically although most people do not rely on them to substitute for the tension tie ability of a ceiling/floor joist. When using them, you have to know if they were framed properly.

One unavoidable issue with a new ridge beam is the sag that occurs under the new loading as you cut out the tension ties. The sag will tend to allow some outward movement of the walls. This coupled with interior walls can give a little of a wavy look at times.

 

[TRAK.Structural]

What are the floor joists for the loft? I can already see the homeowner is saying "That ridge beam is too low".

It's all 2x, 80+ years old. Yea I can already here that comment too so trying to get out ahead of it.

Why are you adding a beam at the kneewall? Rafters overspanned or spliced at the kneewall?

Mostly to keep in line with the existing support conditions. Guess I could check the span on the rafters to see if they can go the whole way, although I think there will be some additional sag that happens if I remove the kneewall without adding a new beam.