Author Topic: Roof-2 questions-Victoria's cottage or other  (Read 3452 times)

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moselle

  • Guest
Roof-2 questions-Victoria's cottage or other
« on: August 15, 2006, 01:44:02 AM »
Hello again.
I have the Victoria's Cottage plans.

A couple of questions come to mind about the roof on this.
I notice there are no 2nd ceiling joists on the area where the bridge run through.
What keeps the walls from bowing from the downward pressure of the roof?
Or, is it because collar ties are on each rafter?
Can this be applied to the little cabin as well?
(ie: collar ties only without ceiling joists to create more headroom?)
Or, even on Victoria's Cottage, could the entire 2nd floor joists be eliminated if a person wanted, and have the area open from floor to collar tie?

My second question pertains to the roof ventilation.
I notice in the plan there is a ridge vent and also a "triangular screened vent @ gables ends"
Can the ridge vent be eliminated if the gable vents are used?
(I am hoping for a "yes" answer on this)

Thanks
« Last Edit: August 15, 2006, 01:45:02 AM by moselle »

jraabe

  • Guest
Re: Roof-2 questions-Victoria's cottage or other
« Reply #1 on: August 15, 2006, 04:55:07 AM »
In Vicitoria's Cottage the rafters are supported by a ridge beam at the top and the sidewalls at the bottom - this eliminates the need for collar ties and truss type roof configurations. This could be done in any of the cottages or cabin designs but is a bit more complex to build and the beam needs to be sized for the load and span.

In the Alternative cross section (sht. 1) there is no ridge beam and the collar ties and plywood splices turn the rafters into a truss. If both ends of that attic were screened openings you could eliminate the ridge vent if desired.


moselle

  • Guest
Re: Roof-2 questions-Victoria's cottage or other
« Reply #2 on: August 15, 2006, 03:32:36 PM »
Ah, so the 6x8 wall beam takes the pressure on kitchen side of "section A-A"?
I am still not exactly clear why the other side doesn't bow, maybe something I shouldn't worry about?

Another thing, so the collar ties take the pressure, how high can they safely be adjusted for max headroom from the ridge down?

No bird's mouth cuts required on the "alt. cross section" rafters?
The Simpson H-10s will do it?

Thanks



jraabe

  • Guest
Re: Roof-2 questions-Victoria's cottage or other
« Reply #3 on: August 15, 2006, 09:38:11 PM »
Yes in a beam system the forces go into the beams. This is a time tested system (timber framing).

In the alternative section the Simpson bracket replaces the birds mouth cut and keeps the truss sitting high up on the wall where the rafter tie (collar tie at 8') needs to be not much more than 1/3 up the rafter to produce its best work. This diagram shows a site built truss that many folks would prefer to build themselves, but lots of other configurations could be designed by your local truss company. These could be more specifically tailored to your local loads, roof covering, pitch, etc. and may be less expensive than making an overbuilt one yourself.
« Last Edit: August 16, 2006, 05:41:31 AM by jraabe »

 

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