I am planning to build a porch roof attached to the back of my house. It will have a trussed roof. The room will be 14' x 14'. I plan to support this with one end attached to the house and the other two corners supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides need to be to support the roof. There will be a 16" overhang on each side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the truss is pretty close to 9' so the area of the roof (that each beam will support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,


I'd check with the building inspector. Local codes may dictate
something, especially with snow loads in the north or hurricane winds
in the south. .

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

Can't say from here. Check again with DIYBanter or in Canada.

In America I cut a beam down to 22 feet. It hasn't failed yet.

"69roadrunner" wrote in message
...

I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,




--
69roadrunner

Start with local inspector/building permit department. Whatever you may
think is acceptable, or what is posted here is worth the paper it is printed
on. What is acceptable where I am may not be where you are. Sometimes it
makes it a lot easier, and sometimes, it makes the bar higher. Whatever,
the man that eventually inspects it is the one who needs to be happy.

HTH

Steve

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

How long is each beam? What loads are a part of the 43.3 psf and
what is the plf on the beam? Is there any depth of beam restrictions?
If so, maybe a glulam product might work better or a dual beam. I
think a couple of uploaded construction pics would help explain more
here.

On Tue, 17 Jul 2012 07:13:33 -0500, "Doug"
wrote:

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

How long is each beam? What loads are a part of the 43.3 psf and
what is the plf on the beam? Is there any depth of beam restrictions?
If so, maybe a glulam product might work better or a dual beam. I
think a couple of uploaded construction pics would help explain more
here.

Oops, you already answered the first question.

"69roadrunner" wrote in message
...

I am planning to build a porch roof attached to the back of my house. . .
.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang . . .

This requires a building permit (in most jurisdictions.) The municipal
or county office that issues building permits can probably answer your
question (without charge.)

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

On Jul 17, 8:15*am, "Doug" wrote:
On Tue, 17 Jul 2012 07:13:33 -0500, "Doug"
wrote:





On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:

I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

How long is each beam? * What loads are a part of the 43.3 psf and
what is the plf on the beam? *Is there any depth of beam restrictions?
If so, maybe a glulam product might work better or a dual beam. * I
think a couple of uploaded construction pics would help explain more
here.

Oops, you already answered the first question. *- Hide quoted text -

- Show quoted text -

There are probably online beam load calculators that
could answer the question. But every place I know you
would need a building permit to add a porch on to a
house. And here to get that building permit you need
a drawing signed and stamped by a licensed architect.
So, I'd start with finding out what it takes to get a building
permit. If it's like here, you'd be wasting your time
figuring it out because the architect is going to do it
anyway.

On Tue, 17 Jul 2012 06:05:14 -0700 (PDT), "
wrote:

On Jul 17, 8:15*am, "Doug" wrote:
On Tue, 17 Jul 2012 07:13:33 -0500, "Doug"
wrote:





On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:

I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

How long is each beam? * What loads are a part of the 43.3 psf and
what is the plf on the beam? *Is there any depth of beam restrictions?
If so, maybe a glulam product might work better or a dual beam. * I
think a couple of uploaded construction pics would help explain more
here.

Oops, you already answered the first question. *- Hide quoted text -

- Show quoted text -

There are probably online beam load calculators that
could answer the question. But every place I know you
would need a building permit to add a porch on to a
house. And here to get that building permit you need
a drawing signed and stamped by a licensed architect.
So, I'd start with finding out what it takes to get a building
permit. If it's like here, you'd be wasting your time
figuring it out because the architect is going to do it
anyway.


I guess you are right because everyone is saying the same thing. I
wanted to answer his question directly but just need more info but
that will not address the legal aspects of building it.

On Tue, 17 Jul 2012 10:06:10 -0500, "Doug"
wrote:

There are probably online beam load calculators that
could answer the question. But every place I know you
would need a building permit to add a porch on to a
house. And here to get that building permit you need
a drawing signed and stamped by a licensed architect.
So, I'd start with finding out what it takes to get a building
permit. If it's like here, you'd be wasting your time
figuring it out because the architect is going to do it
anyway.


I guess you are right because everyone is saying the same thing. I
wanted to answer his question directly but just need more info but
that will not address the legal aspects of building it.

The OP is in Canada.

On Tue, 17 Jul 2012 08:16:36 -0700, Oren wrote:

On Tue, 17 Jul 2012 10:06:10 -0500, "Doug"
wrote:

There are probably online beam load calculators that
could answer the question. But every place I know you
would need a building permit to add a porch on to a
house. And here to get that building permit you need
a drawing signed and stamped by a licensed architect.
So, I'd start with finding out what it takes to get a building
permit. If it's like here, you'd be wasting your time
figuring it out because the architect is going to do it
anyway.


I guess you are right because everyone is saying the same thing. I
wanted to answer his question directly but just need more info but
that will not address the legal aspects of building it.

The OP is in Canada.


Ooh okay. Though I wanted to help, I do think the local jurisdiction
(building dept) could give more help because they will know the loads
to consider, foundation tips, etc... .

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

I would not build anything with a 14 foot span. You'll get eventual sag
in the middle no matter what you use, unless it's a steel girder. Use a
center post. Seven feet is easy to span and much stronger.

On Tue, 17 Jul 2012 13:30:23 -0500, wrote:

On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
wrote:


I am planning to build a porch roof attached to the back of my house. It
will have a trussed roof. The room will be 14' x 14'. I plan to support
this with one end attached to the house and the other two corners
supported by 6 X 6 pressure treated posts.

What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam will
support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Thanks,

I would not build anything with a 14 foot span. You'll get eventual sag
in the middle no matter what you use, unless it's a steel girder. Use a
center post. Seven feet is easy to span and much stronger.


Well yes and no. There is always some sag no matter what you use but
it can be designed within acceptable limits. He can also use knee
braces to cut down on the span if they aren't in the way.

On Tue, 17 Jul 2012 13:30:23 -0500, wrote:




I would not build anything with a 14 foot span. You'll get eventual sag
in the middle no matter what you use, unless it's a steel girder. Use a
center post. Seven feet is easy to span and much stronger.

Seriously? There are tens of thousands of homes that span 16, 18, 20
feet and have no supports on some beams.

On 7/17/2012 5:00 PM, Ed Pawlowski wrote:
On Tue, 17 Jul 2012 13:30:23 -0500, wrote:




I would not build anything with a 14 foot span. You'll get eventual sag
in the middle no matter what you use, unless it's a steel girder. Use a
center post. Seven feet is easy to span and much stronger.

Seriously? There are tens of thousands of homes that span 16, 18, 20
feet and have no supports on some beams.


Good point, a typical double garage door is what, 16-18'?

On Tue, 17 Jul 2012 17:24:20 -0400, "Norm A. Brams"
wrote:

On 7/17/2012 5:00 PM, Ed Pawlowski wrote:
On Tue, 17 Jul 2012 13:30:23 -0500, wrote:




I would not build anything with a 14 foot span. You'll get eventual sag
in the middle no matter what you use, unless it's a steel girder. Use a
center post. Seven feet is easy to span and much stronger.

Seriously? There are tens of thousands of homes that span 16, 18, 20
feet and have no supports on some beams.


Good point, a typical double garage door is what, 16-18'?

Saw one, a concrete poured beam (lentil?) in a house that broke in the
center and sagged over the garage door. Seemed odd to me as it was a
first.

The roof trusses dropped a few inches -- causing further roof damage.

Strange to say the least.

Yes, I know I'll need a permit but there is no requirement for "architectural drawings" as long as the plans meet code. And there's no point in pursuing anything if the beam is going to be so goddamn big it doesn't blend with its surroundings!

On Jul 17, 8:25*pm, 69roadrunner
wrote:
'Oren[_2_ Wrote:





;2893660']On Tue, 17 Jul 2012 10:06:10 -0500, "Doug"

wrote:
--
There are probably online beam load calculators that
could answer the question. *But every place I know you
would need a building permit to add a porch on to a
house. *And here to get that building permit you need
a drawing signed and stamped by a licensed architect.
So, I'd start with finding out what it takes to get a building
permit. *If it's like here, you'd be wasting your time
figuring it out because the architect is going to do it
anyway.-

I guess you are right because everyone is saying the same thing. *I
wanted to answer his question directly but just need more info but
that will not address the legal aspects of building it.-

The OP is in Canada.

Yes, I know I'll need a permit but there is no requirement for
"architectural drawings" as long as the plans meet code. And there's no
point in pursuing anything if the beam is going to be so goddamn big it
doesn't blend with its surroundings!

--
69roadrunner- Hide quoted text -

- Show quoted text -

Have you tried googling for online beam load
calcualtors? I've seen them. I find it interesting that
there are municipalities where they will approve something
that is structural like this without an architect or engineer
signing off on it. I mean I don't know that there is a
specific code that just says for X porch you need Y
beam. It would seem an architect or engineer would
have to do the load analysis and make that decision.
And it just seems odd that a local code official wants
to be in the position of engineer of record for free for
someone's building project.

On Wed, 18 Jul 2012 05:13:46 -0700 (PDT), "
wrote:

Have you tried googling for online beam load
calcualtors? I've seen them. I find it interesting that
there are municipalities where they will approve something
that is structural like this without an architect or engineer
signing off on it. I mean I don't know that there is a
specific code that just says for X porch you need Y
beam. It would seem an architect or engineer would
have to do the load analysis and make that decision.
And it just seems odd that a local code official wants
to be in the position of engineer of record for free for
someone's building project.

In Nevada a home owner can act as their own contractor.

I submitted a rough drawing with dimensions and the permit office gave
me detailed drawings for footers, determined beam size, roof pitch,
etc., based on having Spanish roofing tiles. Granted this was just a
patio cover with some electrical work -- finished stucco. An
architect in the permit reviewed what I "'wanted to build". Then
issued the permit. Very helpful.

A friend and I completed the work. He is experienced in construction
more than I am (or will be) and was a great help. Saved plenty of
money this way.

I am planning to build a porch roof attached to the back of my house.
It will have a trussed roof. The room will be 14' x 14'. I plan to
support this with one end attached to the house and the other two
corners supported by 6 X 6 pressure treated posts.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam
will support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Just so I'm understanding correctly, you will have two beams running
perpendicular to the house, with the trusses sitting on top parallel to
the house? I assume you will be installing some kind of support posts on
the house side of the wall as well, and not just relying on brackets or
something?

Your room is 14' wide with 16" overhang on each end for a total width of
16.7 feet.

The length is 14' with a 16" overhang for a total length of 15.3 feet.

16.7 width x 15.3 length = 256.5 sq/ft

Half of that load is carried by each beam, or approximately 128 sq/ft.

I will assume a 20 psf dead load (weight of the building materials) and
40 psf live load (people on the roof, snow loads, etc.) for a total load
of 60 psf.

60 psf x 128 sq/ft = 7680 pounds on each beam

If you have a 6x6 post at the outer end, and the house end is supported
inside the wall, your free span would be approximately 13.5 feet. But
I'll err on the side of simplicity and say 14 feet.

The size of the beam will vary depending on the wood species you use, but
I'll assume Douglas Fir since that's common in my area. According the
charts I have, you would need a 6x12 beam on each side to support 7680
pounds over a 14' span (assuming you want less than a 1/360 deflection).
That's probably a lot larger than you were picturing.

If you live in a warm climate without snow loads, you could probably get
by with a 6x10 beam.

However, if you add another post to reduce the span to 7', you would have
60psf x 64 sq/ft = 3840 pounds on each beam. In that case, a simple 4x8
beam would be more than adequate to carry the load.

Of course, you will need to install some kind of diagonal bracing to
prevent the whole structure from swaying sideways in winds or earth
movements (lateral loads).

Good luck,

Anthony Watson
www.anthonywatson.us
www.mountain-software.com

On Wed, 18 Jul 2012 14:51:54 +0000 (UTC), HerHusband
wrote:

I am planning to build a porch roof attached to the back of my house.
It will have a trussed roof. The room will be 14' x 14'. I plan to
support this with one end attached to the house and the other two
corners supported by 6 X 6 pressure treated posts.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of the
truss is pretty close to 9' so the area of the roof (that each beam
will support) is about 126 sq.ft.. Total load per beam of 5456 lbs

Just so I'm understanding correctly, you will have two beams running
perpendicular to the house, with the trusses sitting on top parallel to
the house? I assume you will be installing some kind of support posts on
the house side of the wall as well, and not just relying on brackets or
something?

Your room is 14' wide with 16" overhang on each end for a total width of
16.7 feet.

The length is 14' with a 16" overhang for a total length of 15.3 feet.

16.7 width x 15.3 length = 256.5 sq/ft

Half of that load is carried by each beam, or approximately 128 sq/ft.

I will assume a 20 psf dead load (weight of the building materials) and
40 psf live load (people on the roof, snow loads, etc.) for a total load
of 60 psf.

60 psf x 128 sq/ft = 7680 pounds on each beam

If you have a 6x6 post at the outer end, and the house end is supported
inside the wall, your free span would be approximately 13.5 feet. But
I'll err on the side of simplicity and say 14 feet.

The size of the beam will vary depending on the wood species you use, but
I'll assume Douglas Fir since that's common in my area. According the
charts I have, you would need a 6x12 beam on each side to support 7680
pounds over a 14' span (assuming you want less than a 1/360 deflection).
That's probably a lot larger than you were picturing.

If you live in a warm climate without snow loads, you could probably get
by with a 6x10 beam.

However, if you add another post to reduce the span to 7', you would have
60psf x 64 sq/ft = 3840 pounds on each beam. In that case, a simple 4x8
beam would be more than adequate to carry the load.

Of course, you will need to install some kind of diagonal bracing to
prevent the whole structure from swaying sideways in winds or earth
movements (lateral loads).

Good luck,

Anthony Watson
www.anthonywatson.us
www.mountain-software.com


I can't say for sure without more info but I suspect your LL is too
high.

I can't say for sure without more info but I suspect
your [40psf] Live Load is too high.

I wasn't sure where the OP was located, so I erred on the side of heavier
snow loads. I've always used 30psf for live load calculations here in my
area. In any case, I calculated it with the 30 psf and still came up with
about the same size beam.

When we built our house, I asked the truss company to design for 50 psf
live loads, since we occasionally get heavy snow in the winter. Ironically,
the only change this required in the trusses was slightly larger metal
connecting plates. Kind of surprised me.

Anthony Watson
www.anthonywatson.us
www.mountain-software.com

On Wed, 18 Jul 2012 21:14:38 +0000 (UTC), HerHusband
wrote:

I can't say for sure without more info but I suspect
your [40psf] Live Load is too high.

I wasn't sure where the OP was located, so I erred on the side of heavier
snow loads. I've always used 30psf for live load calculations here in my
area. In any case, I calculated it with the 30 psf and still came up with
about the same size beam.

When we built our house, I asked the truss company to design for 50 psf
live loads, since we occasionally get heavy snow in the winter. Ironically,
the only change this required in the trusses was slightly larger metal
connecting plates. Kind of surprised me.

Anthony Watson
www.anthonywatson.us
www.mountain-software.com


grin. People often overlook the connections and seem to just worry
about the beams / columns. Usually we try to make the connections
stronger than the beam because if it fails at the connection, it can
be sudden vs. the beam, usually bends before failing allowing people
to get off. I'm a retired structural engineer so I speak from
experience. Most of my experience is in steel / concrete but for a
short part of my career I did wood (homes). Be careful tho when
using your liveload because if you take full snowload with a full
liveload (think what liveload is meant to include here), that's not
likely in a real world sense. Sometimes in engineering we have to
make educated guesses what we think the real loads will be over the
life of a structure. Of course we would like to over design but
depending on the structure, that can be too costly and most clients
don't like that. Last, I commend you for thinking about loads when
building your home... most people take this for granted.

Anthony, thanks for your detailed reply. All your assumptions are correct except for the load which, if I understand the truss specs correctly, is only 43.3 psf.

Anyhow, I went to the city and they said any lumberyard could do the calc as well as supply engineered drawings (which appear to be all computer generated these days anyhow). The local yard I went to had them within minutes and recommended an engineered beam of 3" x 10". However, since I want to temporarily enclose this each winter I'm thinking I just may add some additional posts so there's something to attach the wall material to. However this is a lot more work (which I was trying to avoid with only 2 posts) since it involves cutting into an existing poured slab in order to install the sonotubes and poured piers. Nothin's ever easy !!!!!!!!!

On Thu, 19 Jul 2012 01:09:30 +0000, 69roadrunner
wrote:


'Doug[_14_ Wrote:
;2894179']On Wed, 18 Jul 2012 14:51:54 +0000 (UTC), HerHusband
wrote:
--
I am planning to build a porch roof attached to the back of my house.
It will have a trussed roof. The room will be 14' x 14'. I plan to
support this with one end attached to the house and the other two
corners supported by 6 X 6 pressure treated posts.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of
the
truss is pretty close to 9' so the area of the roof (that each beam
will support) is about 126 sq.ft.. Total load per beam of 5456 lbs-

Just so I'm understanding correctly, you will have two beams running
perpendicular to the house, with the trusses sitting on top parallel to

the house? I assume you will be installing some kind of support posts on

the house side of the wall as well, and not just relying on brackets or

something?

Your room is 14' wide with 16" overhang on each end for a total width of

16.7 feet.

The length is 14' with a 16" overhang for a total length of 15.3 feet.

16.7 width x 15.3 length = 256.5 sq/ft

Half of that load is carried by each beam, or approximately 128 sq/ft.

I will assume a 20 psf dead load (weight of the building materials) and

40 psf live load (people on the roof, snow loads, etc.) for a total load

of 60 psf.

60 psf x 128 sq/ft = 7680 pounds on each beam

If you have a 6x6 post at the outer end, and the house end is supported

inside the wall, your free span would be approximately 13.5 feet. But
I'll err on the side of simplicity and say 14 feet.

The size of the beam will vary depending on the wood species you use,
but
I'll assume Douglas Fir since that's common in my area. According the
charts I have, you would need a 6x12 beam on each side to support 7680
pounds over a 14' span (assuming you want less than a 1/360 deflection).

That's probably a lot larger than you were picturing.

If you live in a warm climate without snow loads, you could probably get

by with a 6x10 beam.

However, if you add another post to reduce the span to 7', you would
have
60psf x 64 sq/ft = 3840 pounds on each beam. In that case, a simple 4x8

beam would be more than adequate to carry the load.

Of course, you will need to install some kind of diagonal bracing to
prevent the whole structure from swaying sideways in winds or earth
movements (lateral loads).

Good luck,

Anthony Watson
'Anthony Watson of Camas, WA' (http://www.anthonywatson.us)
'Mountain Software Home - Recipe Software, Address Book Software,
Calendar Software' (http://www.mountain-software.com)-


I can't say for sure without more info but I suspect your LL is too
high.

Anthony, thanks for your detailed reply. All your assumptions are
correct except for the load which, if I understand the truss specs
correctly, is only 43.3 psf.

Anyhow, I went to the city and they said any lumberyard could do the
calc as well as supply engineered drawings (which appear to be all
computer generated these days anyhow). The local yard I went to had them
within minutes and recommended an engineered beam of 3" x 10". However,
since I want to temporarily enclose this each winter I'm thinking I just
may add some additional posts so there's something to attach the wall
material to. However this is a lot more work (which I was trying to
avoid with only 2 posts) since it involves cutting into an existing
poured slab in order to install the sonotubes and poured piers. Nothin's
ever easy !!!!!!!!!


I hope they also checked for your deflection??? I don't know still
what your PLF is but my hunch is your deflection is okay with a 10"
beam depth. The width does little for the deflection.

On Thu, 19 Jul 2012 00:23:17 -0500, "Doug"
wrote:

On Thu, 19 Jul 2012 01:09:30 +0000, 69roadrunner
wrote:


'Doug[_14_ Wrote:
;2894179']On Wed, 18 Jul 2012 14:51:54 +0000 (UTC), HerHusband
wrote:
--
I am planning to build a porch roof attached to the back of my house.
It will have a trussed roof. The room will be 14' x 14'. I plan to
support this with one end attached to the house and the other two
corners supported by 6 X 6 pressure treated posts.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of
the
truss is pretty close to 9' so the area of the roof (that each beam
will support) is about 126 sq.ft.. Total load per beam of 5456 lbs-

Just so I'm understanding correctly, you will have two beams running
perpendicular to the house, with the trusses sitting on top parallel to

the house? I assume you will be installing some kind of support posts on

the house side of the wall as well, and not just relying on brackets or

something?

Your room is 14' wide with 16" overhang on each end for a total width of

16.7 feet.

The length is 14' with a 16" overhang for a total length of 15.3 feet.

16.7 width x 15.3 length = 256.5 sq/ft

Half of that load is carried by each beam, or approximately 128 sq/ft.

I will assume a 20 psf dead load (weight of the building materials) and

40 psf live load (people on the roof, snow loads, etc.) for a total load

of 60 psf.

60 psf x 128 sq/ft = 7680 pounds on each beam

If you have a 6x6 post at the outer end, and the house end is supported

inside the wall, your free span would be approximately 13.5 feet. But
I'll err on the side of simplicity and say 14 feet.

The size of the beam will vary depending on the wood species you use,
but
I'll assume Douglas Fir since that's common in my area. According the
charts I have, you would need a 6x12 beam on each side to support 7680
pounds over a 14' span (assuming you want less than a 1/360 deflection).

That's probably a lot larger than you were picturing.

If you live in a warm climate without snow loads, you could probably get

by with a 6x10 beam.

However, if you add another post to reduce the span to 7', you would
have
60psf x 64 sq/ft = 3840 pounds on each beam. In that case, a simple 4x8

beam would be more than adequate to carry the load.

Of course, you will need to install some kind of diagonal bracing to
prevent the whole structure from swaying sideways in winds or earth
movements (lateral loads).

Good luck,

Anthony Watson
'Anthony Watson of Camas, WA' (http://www.anthonywatson.us)
'Mountain Software Home - Recipe Software, Address Book Software,
Calendar Software' (http://www.mountain-software.com)-


I can't say for sure without more info but I suspect your LL is too
high.

Anthony, thanks for your detailed reply. All your assumptions are
correct except for the load which, if I understand the truss specs
correctly, is only 43.3 psf.

Anyhow, I went to the city and they said any lumberyard could do the
calc as well as supply engineered drawings (which appear to be all
computer generated these days anyhow). The local yard I went to had them
within minutes and recommended an engineered beam of 3" x 10". However,
since I want to temporarily enclose this each winter I'm thinking I just
may add some additional posts so there's something to attach the wall
material to. However this is a lot more work (which I was trying to
avoid with only 2 posts) since it involves cutting into an existing
poured slab in order to install the sonotubes and poured piers. Nothin's
ever easy !!!!!!!!!


I hope they also checked for your deflection??? I don't know still
what your PLF is but my hunch is your deflection is okay with a 10"
beam depth. The width does little for the deflection.

BTW, I was still assuming 14' length above. If you shorten it to say
7 feet, likely anything 2x6 or more will be fine for deflection.

That said, do you really need an extra post for temporary walls? Maybe
you do but I was hoping there was another way. I guess it depends on
what the wall material is.

Well there's always a way - right ?!?!? Currently the "walls" are just some 1x3 spruce frames with plastic vapor barrier stapled to it. It just has to keep the snow out. But I'm thinking I'd like to enclose the lower half with a 3' cedar wall and then do something a little more rigid (but still temporary) around the top for winter. Posts every 7' wouldn't look all that bad and would give me something to build on.

What's "PLF" ??

On Fri, 20 Jul 2012 00:11:47 +0000, 69roadrunner
wrote:


'Doug[_14_ Wrote:
;2894474']On Thu, 19 Jul 2012 00:23:17 -0500, "Doug"

wrote:
-
On Thu, 19 Jul 2012 01:09:30 +0000, 69roadrunner
wrote:
-

'Doug[_14_ Wrote: -
;2894179']On Wed, 18 Jul 2012 14:51:54 +0000 (UTC), HerHusband
wrote:
--
I am planning to build a porch roof attached to the back of my house.
It will have a trussed roof. The room will be 14' x 14'. I plan to
support this with one end attached to the house and the other two
corners supported by 6 X 6 pressure treated posts.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of
the
truss is pretty close to 9' so the area of the roof (that each beam
will support) is about 126 sq.ft.. Total load per beam of 5456 lbs-

Just so I'm understanding correctly, you will have two beams running
perpendicular to the house, with the trusses sitting on top parallel
to

the house? I assume you will be installing some kind of support posts
on

the house side of the wall as well, and not just relying on brackets
or

something?

Your room is 14' wide with 16" overhang on each end for a total width
of

16.7 feet.

The length is 14' with a 16" overhang for a total length of 15.3 feet.

16.7 width x 15.3 length = 256.5 sq/ft

Half of that load is carried by each beam, or approximately 128 sq/ft.

I will assume a 20 psf dead load (weight of the building materials)
and

40 psf live load (people on the roof, snow loads, etc.) for a total
load

of 60 psf.

60 psf x 128 sq/ft = 7680 pounds on each beam

If you have a 6x6 post at the outer end, and the house end is
supported

inside the wall, your free span would be approximately 13.5 feet. But
I'll err on the side of simplicity and say 14 feet.

The size of the beam will vary depending on the wood species you use,
but
I'll assume Douglas Fir since that's common in my area. According the
charts I have, you would need a 6x12 beam on each side to support 7680

pounds over a 14' span (assuming you want less than a 1/360
deflection).

That's probably a lot larger than you were picturing.

If you live in a warm climate without snow loads, you could probably
get

by with a 6x10 beam.

However, if you add another post to reduce the span to 7', you would
have
60psf x 64 sq/ft = 3840 pounds on each beam. In that case, a simple
4x8

beam would be more than adequate to carry the load.

Of course, you will need to install some kind of diagonal bracing to
prevent the whole structure from swaying sideways in winds or earth
movements (lateral loads).

Good luck,

Anthony Watson
'Anthony Watson of Camas, WA' ('Anthony Watson of Camas, WA'
(http://www.anthonywatson.us))
'Mountain Software Home - Recipe Software, Address Book Software,
Calendar Software' (http://www.mountain-software.com)-


I can't say for sure without more info but I suspect your LL is too
high.-

Anthony, thanks for your detailed reply. All your assumptions are
correct except for the load which, if I understand the truss specs
correctly, is only 43.3 psf.

Anyhow, I went to the city and they said any lumberyard could do the
calc as well as supply engineered drawings (which appear to be all
computer generated these days anyhow). The local yard I went to had
them
within minutes and recommended an engineered beam of 3" x 10". However,
since I want to temporarily enclose this each winter I'm thinking I
just
may add some additional posts so there's something to attach the wall
material to. However this is a lot more work (which I was trying to
avoid with only 2 posts) since it involves cutting into an existing
poured slab in order to install the sonotubes and poured piers.
Nothin's
ever easy !!!!!!!!!-


I hope they also checked for your deflection??? I don't know still
what your PLF is but my hunch is your deflection is okay with a 10"
beam depth. The width does little for the deflection. -

BTW, I was still assuming 14' length above. If you shorten it to say
7 feet, likely anything 2x6 or more will be fine for deflection.

That said, do you really need an extra post for temporary walls? Maybe
you do but I was hoping there was another way. I guess it depends on
what the wall material is.

Well there's always a way - right ?!?!? Currently the "walls" are just
some 1x3 spruce frames with plastic vapor barrier stapled to it. It just
has to keep the snow out. But I'm thinking I'd like to enclose the lower
half with a 3' cedar wall and then do something a little more rigid (but
still temporary) around the top for winter. Posts every 7' wouldn't look
all that bad and would give me something to build on.

What's "PLF" ??

pounds per lineal foot
ref: http://www.beamchek.com/loadbook/page5.html

On Fri, 20 Jul 2012 00:11:47 +0000, 69roadrunner
wrote:


'Doug[_14_ Wrote:
;2894474']On Thu, 19 Jul 2012 00:23:17 -0500, "Doug"

wrote:
-
On Thu, 19 Jul 2012 01:09:30 +0000, 69roadrunner
wrote:
-

'Doug[_14_ Wrote: -
;2894179']On Wed, 18 Jul 2012 14:51:54 +0000 (UTC), HerHusband
wrote:
--
I am planning to build a porch roof attached to the back of my house.
It will have a trussed roof. The room will be 14' x 14'. I plan to
support this with one end attached to the house and the other two
corners supported by 6 X 6 pressure treated posts.
What I need to know is what size each of the beams spanning the sides
need to be to support the roof. There will be a 16" overhang on each
side. Roof pitch is 4.5/12. Load is 43.3 psf. Length of one side of
the
truss is pretty close to 9' so the area of the roof (that each beam
will support) is about 126 sq.ft.. Total load per beam of 5456 lbs-

Just so I'm understanding correctly, you will have two beams running
perpendicular to the house, with the trusses sitting on top parallel
to

the house? I assume you will be installing some kind of support posts
on

the house side of the wall as well, and not just relying on brackets
or

something?

Your room is 14' wide with 16" overhang on each end for a total width
of

16.7 feet.

The length is 14' with a 16" overhang for a total length of 15.3 feet.

16.7 width x 15.3 length = 256.5 sq/ft

Half of that load is carried by each beam, or approximately 128 sq/ft.

I will assume a 20 psf dead load (weight of the building materials)
and

40 psf live load (people on the roof, snow loads, etc.) for a total
load

of 60 psf.

60 psf x 128 sq/ft = 7680 pounds on each beam

If you have a 6x6 post at the outer end, and the house end is
supported

inside the wall, your free span would be approximately 13.5 feet. But
I'll err on the side of simplicity and say 14 feet.

The size of the beam will vary depending on the wood species you use,
but
I'll assume Douglas Fir since that's common in my area. According the
charts I have, you would need a 6x12 beam on each side to support 7680

pounds over a 14' span (assuming you want less than a 1/360
deflection).

That's probably a lot larger than you were picturing.

If you live in a warm climate without snow loads, you could probably
get

by with a 6x10 beam.

However, if you add another post to reduce the span to 7', you would
have
60psf x 64 sq/ft = 3840 pounds on each beam. In that case, a simple
4x8

beam would be more than adequate to carry the load.

Of course, you will need to install some kind of diagonal bracing to
prevent the whole structure from swaying sideways in winds or earth
movements (lateral loads).

Good luck,

Anthony Watson
'Anthony Watson of Camas, WA' ('Anthony Watson of Camas, WA'
(http://www.anthonywatson.us))
'Mountain Software Home - Recipe Software, Address Book Software,
Calendar Software' (http://www.mountain-software.com)-


I can't say for sure without more info but I suspect your LL is too
high.-

Anthony, thanks for your detailed reply. All your assumptions are
correct except for the load which, if I understand the truss specs
correctly, is only 43.3 psf.

Anyhow, I went to the city and they said any lumberyard could do the
calc as well as supply engineered drawings (which appear to be all
computer generated these days anyhow). The local yard I went to had
them
within minutes and recommended an engineered beam of 3" x 10". However,
since I want to temporarily enclose this each winter I'm thinking I
just
may add some additional posts so there's something to attach the wall
material to. However this is a lot more work (which I was trying to
avoid with only 2 posts) since it involves cutting into an existing
poured slab in order to install the sonotubes and poured piers.
Nothin's
ever easy !!!!!!!!!-


I hope they also checked for your deflection??? I don't know still
what your PLF is but my hunch is your deflection is okay with a 10"
beam depth. The width does little for the deflection. -

BTW, I was still assuming 14' length above. If you shorten it to say
7 feet, likely anything 2x6 or more will be fine for deflection.

That said, do you really need an extra post for temporary walls? Maybe
you do but I was hoping there was another way. I guess it depends on
what the wall material is.

Well there's always a way - right ?!?!? Currently the "walls" are just
some 1x3 spruce frames with plastic vapor barrier stapled to it. It just
has to keep the snow out. But I'm thinking I'd like to enclose the lower
half with a 3' cedar wall and then do something a little more rigid (but
still temporary) around the top for winter. Posts every 7' wouldn't look
all that bad and would give me something to build on.

What's "PLF" ??


Pounds per lineal foot
ref: http://www.beamchek.com/loadbook/page5.html

replying to trader4, Terry wrote:
Im building a pergola , how far can I span with a 2x8 treated beam. Needing
to be 14.

--
for full context, visit https://www.homeownershub.com/mainte...14-704987-.htm

On 7/19/2018 6:44 PM, Terry wrote:
replying to trader4, Terry wrote:
Im building a pergola , how far can I span with a 2x8 treated beam. Needing
to be 14.

Depends on the quality of the lumber and how much sag can you tolerate.

On 7/19/2018 6:44 PM, Terry wrote:
replying to trader4, Terry wrote:
Im building a pergola , how far can I span with a 2x8 treated beam.
Needing
to be 14.

With no load you can go pretty far. It only has to support itself on a
pergola. You will be good for 14'

On Thursday, July 19, 2018 at 8:47:21 PM UTC-4, Ed Pawlowski wrote:
On 7/19/2018 6:44 PM, Terry wrote:
replying to trader4, Terry wrote:
Im building a pergola , how far can I span with a 2x8 treated beam.
Needing
to be 14.

With no load you can go pretty far. It only has to support itself on a
pergola. You will be good for 14'

Yes and if he googles for floor loading calculator, joist calculator,
beam calculator there are tools online that will give you the various
options depending on the load, span, spacing, type of lumber

On Thu, 19 Jul 2018 18:28:59 -0700 (PDT), trader_4
wrote:

On Thursday, July 19, 2018 at 8:47:21 PM UTC-4, Ed Pawlowski wrote:
On 7/19/2018 6:44 PM, Terry wrote:
replying to trader4, Terry wrote:
Im building a pergola , how far can I span with a 2x8 treated beam.
Needing
to be 14.

With no load you can go pretty far. It only has to support itself on a
pergola. You will be good for 14'

Yes and if he googles for floor loading calculator, joist calculator,
beam calculator there are tools online that will give you the various
options depending on the load, span, spacing, type of lumber

They spanned 12' with 2x8 hem/fir around 14" O/C in my house in Md and
it never fell down. The design load was around 40 per sq/ft as I
recall.
Like Ed says, in a pergola where there is not much else up there it
should be fine unless they strap the top with 1x4s to block the sun
and you end up with a snow load. The one that was here in Florida when
I moved in was spanning 13' with 2x6 SYP.