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What size beam to span 14'
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69roadrunner
Jul 16, 2012, 8:53:45 PM7/16/12
to
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
Ed Pawlowski
Jul 16, 2012, 10:26:08 PM7/16/12
to
something, especially with snow loads in the north or hurricane winds
in the south. .
Oren
Jul 16, 2012, 10:28:34 PM7/16/12
to
In America I cut a beam down to 22 feet. It hasn't failed yet.
Steve B
Jul 16, 2012, 11:38:11 PM7/16/12
to
"69roadrunner" <69roadrunn...@diybanter.com> wrote in message
news:69roadrunn...@diybanter.com...
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
Doug
Jul 17, 2012, 8:13:33 AM7/17/12
to
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.
Doug
Jul 17, 2012, 8:15:13 AM7/17/12
to
On Tue, 17 Jul 2012 07:13:33 -0500, "Doug" <noemail...@msn.com>
wrote:
Oops, you already answered the first question.
wrote:
tra...@optonline.net
Jul 17, 2012, 9:05:14 AM7/17/12
to
On Jul 17, 8:15 am, "Doug" <noemailaddr...@msn.com> wrote:
> On Tue, 17 Jul 2012 07:13:33 -0500, "Doug" <noemailaddr...@msn.com>
> 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 07:13:33 -0500, "Doug" <noemailaddr...@msn.com>
>
> - 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.
Don Phillipson
Jul 17, 2012, 8:40:10 AM7/17/12
to
> I am planning to build a porch roof attached to the back of my house. . .
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)
> .
> 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 . . .
> What I need to know is what size each of the beams spanning the sides
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)
Doug
Jul 17, 2012, 11:06:10 AM7/17/12
to
wanted to answer his question directly but just need more info but
that will not address the legal aspects of building it.
Oren
Jul 17, 2012, 11:16:36 AM7/17/12
to
On Tue, 17 Jul 2012 10:06:10 -0500, "Doug" <noemail...@msn.com>
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.
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.
Doug
Jul 17, 2012, 11:36:29 AM7/17/12
to
(building dept) could give more help because they will know the loads
to consider, foundation tips, etc... .
fred.fl...@thecave.com
Jul 17, 2012, 2:30:23 PM7/17/12
to
On Tue, 17 Jul 2012 00:53:45 +0000, 69roadrunner
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.
Doug
Jul 17, 2012, 3:12:11 PM7/17/12
to
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.
Ed Pawlowski
Jul 17, 2012, 5:00:23 PM7/17/12
to
>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
>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.
feet and have no supports on some beams.
Norm A. Brams
Jul 17, 2012, 5:24:20 PM7/17/12
to
Oren
Jul 17, 2012, 5:55:10 PM7/17/12
to
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.
69roadrunner
Jul 17, 2012, 8:25:34 PM7/17/12
to
'Oren[_2_ Wrote:
> ;2893660']On Tue, 17 Jul 2012 10:06:10 -0500, "Doug"
> noemail...@msn.com
> 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.-
> 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
>
>
> 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.-
>
> 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
>
> The OP is in Canada.
Yes, I know I'll need a permit but there is no requirement for
> The OP is in Canada.
"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
tra...@optonline.net
Jul 18, 2012, 8:13:46 AM7/18/12
to
On Jul 17, 8:25 pm, 69roadrunner <69roadrunner.a4bd...@diybanter.com>
wrote:
> 69roadrunner- Hide quoted text -
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.
wrote:
> 'Oren[_2_ Wrote:
>
>
>
>
>
> > ;2893660']On Tue, 17 Jul 2012 10:06:10 -0500, "Doug"
> > noemailaddr...@msn.com
>
>
>
>
>
> > ;2893660']On Tue, 17 Jul 2012 10:06:10 -0500, "Doug"
>
> - Show quoted text -
Have you tried googling for online beam load
> - Show quoted text -
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.
Oren
Jul 18, 2012, 9:19:20 AM7/18/12
to
On Wed, 18 Jul 2012 05:13:46 -0700 (PDT), "tra...@optonline.net"
<tra...@optonline.net> 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.
<tra...@optonline.net> 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.
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.
HerHusband
Jul 18, 2012, 10:51:54 AM7/18/12
to
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
Doug
Jul 18, 2012, 12:23:19 PM7/18/12
to
high.
HerHusband
Jul 18, 2012, 5:14:38 PM7/18/12
to
> 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
Doug
Jul 18, 2012, 5:42:46 PM7/18/12
to
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.
69roadrunner
Jul 18, 2012, 9:09:30 PM7/18/12
to
'Doug[_14_ Wrote:
> ;2894179']On Wed, 18 Jul 2012 14:51:54 +0000 (UTC), HerHusband
> unk...@unknown.com 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-
> 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
> '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
>
> I can't say for sure without more info but I suspect your LL is too
> high.
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 !!!!!!!!!
--
69roadrunner
Doug
Jul 19, 2012, 1:23:17 AM7/19/12
to
what your PLF is but my hunch is your deflection is okay with a 10"
beam depth. The width does little for the deflection.
Doug
Jul 19, 2012, 1:36:46 AM7/19/12
to
On Thu, 19 Jul 2012 00:23:17 -0500, "Doug" <noemail...@msn.com>
wrote:
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.
wrote:
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.
69roadrunner
Jul 19, 2012, 8:11:47 PM7/19/12
to
'Doug[_14_ Wrote:
> ;2894474']On Thu, 19 Jul 2012 00:23:17 -0500, "Doug"
> noemail...@msn.com
> wrote:
> -
> -
>
> 'Doug[_14_ Wrote: -
> (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.-
> Calendar Software' (http://www.mountain-software.com)-
>
>
> I can't say for sure without more info but I suspect your LL is too
>
> 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 !!!!!!!!!-
> 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
>
>
> 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. -
>
> 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"
>
> 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
> 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.
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" ??
--
69roadrunner
Doug
Jul 19, 2012, 11:12:48 PM7/19/12
to
Doug
Jul 19, 2012, 11:15:43 PM7/19/12
to
Terry
Jul 19, 2018, 6:44:06 PM7/19/18
to
replying to trader4, Terry wrote:
I’m 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/maintenance/what-size-beam-to-span-14-704987-.htm
I’m 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/maintenance/what-size-beam-to-span-14-704987-.htm
Jack Legg Construction
Jul 19, 2018, 8:33:57 PM7/19/18
to
On 7/19/2018 6:44 PM, Terry wrote:
> replying to trader4, Terry wrote:
> I’m 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.
> replying to trader4, Terry wrote:
> I’m building a pergola , how far can I span with a 2x8 treated beam. Needing
> to be 14’.
Ed Pawlowski
Jul 19, 2018, 8:47:21 PM7/19/18
to
On 7/19/2018 6:44 PM, Terry wrote:
> replying to trader4, Terry wrote:
> I’m 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
> I’m building a pergola , how far can I span with a 2x8 treated beam.
> Needing
> to be 14’.
pergola. You will be good for 14'
trader_4
Jul 19, 2018, 9:29:03 PM7/19/18
to
beam calculator there are tools online that will give you the various
options depending on the load, span, spacing, type of lumber
gfre...@aol.com
Jul 19, 2018, 9:46:23 PM7/19/18
to
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.
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