Answer for roof ridge vents

I don’t know who posted it a week or so ago (and the phone lines have been slow enough that the search feature isn’t playing nice) but I found the answer for it regardless.
They wanted to know the name for the elevated portion of a peaked roof that runs the whole length of the building such as so:


Section view:

      /\
      ||  <-windows along these sides
     /  \
    /    \
   /      \
   |      |
   |      |

Elevation view:
   ________________________
  |________________________|
  |W_W_W_W_W_W_W_W_W_W_W_W_|
  |                        |
  |                        |
  |________________________|
  |                        |
  |                        |

That whole unit across the ridge is called a transom, same as above a door. Apparently, it shares the name since it shares the function, they both vent out the hot air from the highest point on the wall.
However, if the space is occupiable (has a floor and is more than 6’ or so), then it is just called a “lantern style” roof. Amazing what happens when you ask a carpenter the right questions…and I didn’t even have to wait 2 weeks for him to get back to me.

I worked with a guy once that had one of those on his garage. He called it a pigeon roost. Of course he raised pigeons

KCB615, that’ll work! That’s exactly the type of roof I’m planning.

I didn’t find the word transom used to define this, but I did find a few sites that defined a lantern as “Any structure rising above the roof of a building and having openings in its sides by which the interior of the building is lighted” (Yes, they all used the same wording.) It would make sense to call the structure a transom, though.

I was also wondering if they really help cool things, but I grew up in/near Galveston where the homes were cooled by transom windows and Gulf breezes. If transom windows can cool things, a transom to the roof should do the same.

FWIW, I’m planning on building it as an extension to the purlins that support the rafters in mid-run. I get the feeling that this will really complicate the roof work, but I’m willing to do it-- anything to keep from running an AC all the time. Besides, I like the look.

Nice drawing, too. Mind if I print it out and draw my stud layout on it? :slight_smile:

Print away! After the time it took me to make it work right with the code command, I should charge you an hourly rate :slight_smile:

If the expense of the transom is going to be a problem, why not go for a cupola? The majority of the roof structure stays the same, and you can still put remotely operated louvers on the cupola (either electrical or cable operated) to vent the hot air out pretty quickly. If you make a large enough cupola, that is. Of course, if you* really* like the look of the transom roof, go for it.

As I’m thinking about setting that structure up, could you build it the same as a ridge vent would be built, only extend it 4’ across the ridge rather than the 6" or so a ridge vent covers? Depending on the pitch of the roof, you most likely wouldn’t be able to see the roof rafters or the ridge board from the outside.


Something like this?
        /\
       /  \
       |  |
       |/\|
       /  \
      /    \
     ~      ~

As opposed to this:
        /\
       /  \
       |  |
       |__|  <- continuation of rafter, not a floor
       /  \
      /    \
     ~      ~

Boy, I’m starting to like that code command

It might make both the design and construction a bit easier. Granted, I don’t know how exactly you were planning to do it, so my rambling and drawing might not affect you.

Sorry for being late with this; work got in the way.

Anyway, here’s the rough idea:


          /\
         /  \
        /----\
       /| /\ |\
        |/  \|
        /____\
       /|    |\
      / |    | \
     /  |    |  \
    /   |    |   \
   /--------------\
  /|              |\
 / |              | \

The vertical parts that act as studs for the lantern should also help triangulate the roof; having the lantern joists tied to the ridge should also help. I’ll probably use something like vertical shades to simplify shutting off the vents.

Adding the structure may not complicate the job too much, but it will mean a lot of dancing over and under the main rafters in a Texas sun. Then again, it may be winter before I get to it…

In any case, thanks for the info.

I’ve always heard that raised section called a clerestory.

You know, you’re right, but I can hear the real estate agent if we ever decide to sell:
“Well, it’s a cozy little cottage, but the garage has a celestory! And…”

I think I may just call it the doghouse on top of the shop…