when is a roof not a roof...

[Rader Ranch]

....or more accurately, not a mass? the roof of the shop i'm converting to a studio (in fact, all 3 structures on this property) is built such that the entire peak of the roof is a vent (minus a couple feet at either end). there's this metal flange dealie-bob that acts as a rain buffer while leaving a couple inch gash the length of the peak, presumably so hot/damp air can escape (IMHO doesn't seem to work well). it's a truss construction, and would be a real PITA to try and seal up from underneath, nor would i expect that to accomplish much regardless. re-roofing is not a budget option.

in the spirit of trying to keep it short but clear: planning 3 rooms, ISO fully floated room-in-room; but control just room in room, and live (due to both budget and our location being fairly isolated) just a well treated room with the ceiling being the bottom of the trusses.

with the roof/mass being that compromised, is there any hope of being able to treat the live room ceiling to at the very least keep out all rain noise and keep the low end out of our house approx. 150' away? or, if it shouldn't even count as a mass layer, then i assume the solution would have to be drywall the entire bottom truss/ceiling then frame new ceilings for all. obviously don't want to do that and create 3 leaves if it's not necesssary.

thanx much for reading....

[sharward]

Welcome to the forum, Rader Ranch!

I used to have a similar roof style on my old house. There was a "step" in it with a pretty small gap between the levels.

In the "mass-air-mass" equation, if the "mass" has a gaping hole in it, it's not really a "mass" -- or if it is, it is not a very effective one at all.

I may be stepping out on a limb here, but I think most of the time roofs are considered "sort of 3rd leaf" because roofs tend to be vented. Although yours is vented in an unusual way (at the top), most are vented along the sides and/or on the walls where they peak.

I think the ideal solution would be (as you indicated) for you to consider the two ceilings in your space, not unlike what I'm planning to do for my project. As I understand it, your roof would still be in the third leaf position, but the fact that it's vented so much mitigates this effect, and may actually assist in isolating some frequencies.

Bear in mind that I'm a "mere mortal" and not really an expert on the subject. If people with actual brains post a different viewpoint, consider my credibility "questionable."

Speaking of "people with actual brains," consider this post by someone with an actual brain -- a very illustrative commentary on "third leaves that aren't really."

If you're still confused, you're not alone, and that's OK -- keep asking if you must.

--Keith

[Rader Ranch]

thanx Keith. i've definitely got plenty of newby gaps (um) in my knowledge in this area, one of which was/is the leaf law and particulars. having once worked for a remodel contractor (going on 15 years ago) isn't exactly enough

this'll be my 2nd home setup. of course the goal is to actually do more things right than wrong this time, (unlike last time so i've learned, mostly through this fantastic forum), and i'm trying my best 'seek and ye shall find', on and off for the last couple months, but there's a lot of ground to cover...and figuring whether this roof really, um, figured in the equation was puzzling me. it obviously effects so many decisions down the line...

IOW, my brain hurts!

[sharward]

IOW, my brain hurts!

No pain, no gain, my friend! Hang in there. You've already learned a lot. Just keep building on that!

--Keith