I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

wrote in message
...
I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 = 14

On Feb 29, 8:35 pm, "Pat" wrote:
wrote in message

...



I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 = 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? Guess I should have paid more attention in
school huh?

wrote in message
...
On Feb 29, 8:35 pm, "Pat" wrote:
wrote in message

...



I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 = 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? Guess I should have paid more attention in
school huh?

Probably need a blackboard so I can draw you a picture. A miter saw makes a
90 degree angle with the fence. To cut a 76 degree angle on the board you
set the saw to 14 degrees.

On Feb 29, 8:52 pm, "Pat" wrote:
wrote in message

...

On Feb 29, 8:35 pm, "Pat" wrote:
wrote in message

...

I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 = 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? Guess I should have paid more attention in
school huh?

Probably need a blackboard so I can draw you a picture. A miter saw makes a
90 degree angle with the fence. To cut a 76 degree angle on the board you
set the saw to 14 degrees.

What most carpenters would do is hold their speed squares on the 3/12
mark, and look down and see what angle the plumb cut corresponds to.
Mathematically orientated carpenters can use a scientific calculator
and enter 3 / 12 INV TAN. Which I guess is technically the angle of
the rafter to the ceiling joist, but it is also the angle that you set
your miter saw to. Like Paul said.

On Feb 29, 8:52 pm, "Pat" wrote:
wrote in message

...

On Feb 29, 8:35 pm, "Pat" wrote:
wrote in message

...

I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 = 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? Guess I should have paid more attention in
school huh?

Probably need a blackboard so I can draw you a picture. A miter saw makes a
90 degree angle with the fence. To cut a 76 degree angle on the board you
set the saw to 14 degrees.

What most carpenters would do is hold their speed squares on the 3/12
mark, and look down and see what angle the plumb cut corresponds to.
Mathematically orientated carpenters can use a scientific calculator
and enter 3 / 12 INV TAN. Which I guess is technically the angle of
the rafter to the ceiling joist, but it is also the angle that you set
your miter saw to. Like Pat said.

On Feb 29, 7:04*pm, marson wrote:
On Feb 29, 8:52 pm, "Pat" wrote:





wrote in message

...

On Feb 29, 8:35 pm, "Pat" wrote:
wrote in message

....

I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). *I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. *The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. *The two 76degree angles would be together
at the ridge of the roof. *What would the plumb cut be in degrees for
the facia board on the ridge? *I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. *The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. *I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 *= 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? *Guess I should have paid more attention in
school huh?

Probably need a blackboard so I can draw you a picture. *A miter saw makes a
90 degree angle with the fence. *To cut a 76 degree angle on the board you
set the saw to 14 degrees.

What most carpenters would do is hold their speed squares on the 3/12
mark, and look down and see what angle the plumb cut corresponds to.
Mathematically orientated carpenters can use a scientific calculator
and enter 3 / 12 INV TAN. * Which I guess is technically the angle of
the rafter to the ceiling joist, but it is also the angle that you set
your miter saw to. *Like Pat said.- Hide quoted text -

- Show quoted text -

Or use a bevel gauge to set the saw to. That's what I do and it
avoids the problem of odd angles. Been a long time since I actually
read degrees of angle on anything.

Harry K

"Pat" wrote in message
...

wrote in message
...
On Feb 29, 8:35 pm, "Pat" wrote:
wrote in message

...



I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. The two 76degree angles would be together
at the ridge of the roof. What would the plumb cut be in degrees for
the facia board on the ridge? I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 = 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? Guess I should have paid more attention in
school huh?

Probably need a blackboard so I can draw you a picture. A miter saw makes
a 90 degree angle with the fence. To cut a 76 degree angle on the board
you set the saw to 14 degrees.


I'll try again. Put the board on the miter saw. The angle is 76 degrees
measured from the fence. The saw is at 90 degrees. You have to move the
saw from 90 degrees to 76 degrees. So you move the saw 90 - 76 = 14
degrees.

On Feb 29, 5:42*pm, wrote:
On Feb 29, 8:35 pm, "Pat" wrote:





wrote in message

...

I have a 3/12 pitch roof (3 inch's of rise for each 12 inch's of
run). *I am installing Facia Board (1x8 pine) and my question concerns
the proper angle cut at the ridge of the roof. *The right angle
triangle by definition of the 3/12 pitch has a 90degree angle at the
top plate center, a 14degree angle at the eave and a 76degree angle at
the ridge (for a total of 180degrees in the right triangle)

Vision a gable roof and the two right triangles would fit against each
other and form the gable. *The two 76degree angles would be together
at the ridge of the roof. *What would the plumb cut be in degrees for
the facia board on the ridge? *I thought that with two 76degree angles
combined that I would split that in half for the cut, but obviously
that is wrong. *The angle cut is not 76degrees and my miter saw
wouldn't cut that anyway. *I think the angle cut may be 14degrees for
each of the facia boards joining at the ridge on the two 76degree
angles, but I don't know why I think that or how the angle is actually
calculated.

Thanks for any assistance with the angle cut.

David

90 minus 76 *= 14

14degrees makes sense, but why am I subtracting from 90degress when
the angle is 76 degrees? *Guess I should have paid more attention in
school huh?- Hide quoted text -

- Show quoted text -

Because the angle at the ridge is 14 degrees, not 76. Eyeball the cut
that will be needed. It is clearly way less than 90. The only 76
degree cut on your roof will be the the birdsmouth cut to sit flat on
top of the plate.

Be sure to cut two short trial pieces and try the fit. With a 1x8
just a minor error on saw set or when they made their pattern rafter
will result in a noticeable gap.

Harry K

Harry K