Building and Construction - Supporting Headers

Author

Supporting Headers

Wayne Whitney

2006-04-11, 3:21 pm

Hello,

I understand the usual way to frame a window or door opening is to
support the end of the header with a jack stud and butt this up
against the full length king stud. [And that for long openings or
high loads, 2 jack studs may be required.] Is there a way to attach
the header directly to the king stud without any jack studs? FWIW my
application is for a 32" door opening in a wall supporting one story
above and the hipped roof load, no floor or ceiling loads. So the
loads involved are quite low.

Cheers, Wayne

Wayne Whitney

2006-04-11, 4:21 pm

On 2006-04-11, Wayne Whitney <whitney@post.harvard.edu> wrote:

> Is there a way to attach the header directly to the king stud
> without any jack studs?

I think I figured it out--my "Code Check Building" includes a footnote
to the table of header spans for exterior bearing walls that "If only
one jack stud is needed, hangers may be used." And I see that Simpson
Strong Tie, for example, makes a connector called a header hanger,
which would presumably be for this situation. Sounds right?

Thanks, Wayne

Bob Morrison

2006-04-11, 4:21 pm

In a previous post Wayne Whitney wrote...
> Is there a way to attach
> the header directly to the king stud without any jack studs? FWIW my
> application is for a 32" door opening in a wall supporting one story
> above and the hipped roof load, no floor or ceiling loads. So the
> loads involved are quite low.

Yes. Simpson HH4 or HH6

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

Wayne Whitney

2006-04-11, 5:21 pm

On 2006-04-11, Bob Morrison <SpamFighter@junk.com> wrote:

> Yes. Simpson HH4 or HH6

Thanks, Wayne

Grumman-581

2006-04-11, 5:21 pm

"Wayne Whitney" <whitney@post.harvard.edu> wrote in message
news:slrne3nsg9.33q.whitney@pizza.private...
> Is there a way to attach the header directly to the
> king stud without any jack studs?

Or you could just add two new king studs outside of the current king studs
and then convert the old king studs into jack studs? Of course, if one of
the studs is already close to a wall intersection, you might need to modify
this a bit...

JerryD\(upstateNY\)

2006-04-16, 6:21 am

>>Or you could just add two new king studs outside of the current king studs
and then convert the old king studs into jack studs? Of course, if one of
the studs is already close to a wall intersection, you might need to modify
this a bit...<<

Or maybe 3/4" jack studs would make the opening wide enough.
As long as you put lots of nails in the jack studs they will hold quite a bit.

--
JerryD(upstateNY

Bob Morrison

2006-04-17, 12:21 pm

In a previous post "JerryD\(upstateNY\)" <jerry@righthere.com> wrote...
> Or maybe 3/4" jack studs would make the opening wide enough.
> As long as you put lots of nails in the jack studs they will hold quite a bit.
>

Jerry:

It's not the jack stud that's really the problem, it the bearing stress on
the bottom of the header. For a small opening that does not carry a roof
or floor above, this might not be much of an issue. But, in many
instances the bearing stress can exceed the capacity of the wood when
loaded perpendicular to the grain. That's why my standard framing notes
require 2 jack studs under the header when the opening is larger than 6
feet.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

Wayne Whitney

2006-04-17, 3:21 pm

On 2006-04-17, Bob Morrison <SpamFighter@junk.com> wrote:

> It's not the jack stud that's really the problem, it the bearing stress on
> the bottom of the header.

According to www.strongtie.com, a HH4 header hanger bracket attached
to a 3x4 king stud is rated for a gravity load of 1195 lbs. While
according to the West Coast Lumber Inspection Bureau douglas fir is
rated for 625 psi for compression perpendenicular to the grain. So a
bearing area of 1.5" x 3.5" yields a rating of 3280 lbs. I'm a bit
surprised by the disparity.

What about using a Simpson HUCQ410-SDS when hanging a nominal 4x10
header? It has a rating of 4955 lbs gravity load when used with
douglas fir. It has the disadvantage of requiring the header to be
inserted into the bracket from above after the bracker is attached to
the king stud(s). Is there any other reason not to use this bracket
to support a header?

Thanks, Wayne

Bob Morrison

2006-04-17, 6:21 pm

In a previous post Wayne Whitney wrote...
> According to www.strongtie.com, a HH4 header hanger bracket attached
> to a 3x4 king stud is rated for a gravity load of 1195 lbs. While
> according to the West Coast Lumber Inspection Bureau douglas fir is
> rated for 625 psi for compression perpendenicular to the grain. So a
> bearing area of 1.5" x 3.5" yields a rating of 3280 lbs. I'm a bit
> surprised by the disparity.
>

I'm not. The HH4 hanger is intended for light weight applications where
adding a jack or trimmer stud is not feasible. I don't believe it is
intended as a replacement for fully framed wall.

> What about using a Simpson HUCQ410-SDS when hanging a nominal 4x10
> header? It has a rating of 4955 lbs gravity load when used with
> douglas fir. It has the disadvantage of requiring the header to be
> inserted into the bracket from above after the bracker is attached to
> the king stud(s). Is there any other reason not to use this bracket
> to support a header?

You could use the HUC type hanger, but it does require (2) 2x or 4x post
to accommodate the screws. When framing from scratch it would be easier
and less expensive to simply frame with 1 or 2 jack studs. The header can
then be installed while the wall is still flat on the floor. Very quick
and easy.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

Wayne Whitney

2006-04-17, 7:21 pm

On 2006-04-17, Bob Morrison <SpamFighter@junk.com> wrote:

> You could use the HUC type hanger, but it does require (2) 2x or 4x
> post to accommodate the screws. When framing from scratch it would
> be easier and less expensive to simply frame with 1 or 2 jack studs.
> The header can then be installed while the wall is still flat on the
> floor.

All my work so far is remodeling, rather than new framing, so that is
my point of view. I have a couple situations where space is tight, so
1.5" or 3" for the jack posts makes a difference. 2 questions:

(1) If an opening is up against a braced wall panel using double 2x4s
for the squash posts, I assume that it would not be OK to cut one of
the 2x4s to utilize it as a jack stud? Or would that be OK, if metal
straps are used across the cut 2x4 to restore the strength in tension?

(2) Do all braced wall sections with holddowns get a double 2x4 for
the squash posts? My specific interest is in the prescriptive
"alternate braced wall panel" (2'8" wide with holddowns) described in
2320.11.4 of the 2001 California Building Code (based on the 1997
UBC). No mention of doubling the boundary 2x4s is made in that
paragraph; is that an implicit requirement, or does it not apply?

The downside of doubling the boundary 2x4s, of course, is that it
makes the holddowns 3" closer together, shortening the base of
support, so perhaps the boundary 2x4s are supposed to be single
members.

Cheers, Wayne

Bob Morrison

2006-04-17, 8:21 pm

In a previous post Wayne Whitney wrote...
> All my work so far is remodeling, rather than new framing, so that is
> my point of view. I have a couple situations where space is tight, so
> 1.5" or 3" for the jack posts makes a difference. 2 questions:
>
> (1) If an opening is up against a braced wall panel using double 2x4s
> for the squash posts, I assume that it would not be OK to cut one of
> the 2x4s to utilize it as a jack stud? Or would that be OK, if metal
> straps are used across the cut 2x4 to restore the strength in tension?

You can use the trimmer or jack stud as part of your "squash" post. This
will be a little situation dependent, but for a door it is not a problem
since the jack stud is usually almost as long as the king stud. You can
put in two rows of edge nails at this location (one in the king and one in
the trimmer). I usually recommend nailing the two studs together with 2
rows of 16d sinkers (10d commons) @ 8" o/c.

> (2) Do all braced wall sections with holddowns get a double 2x4 for
> the squash posts? My specific interest is in the prescriptive
> "alternate braced wall panel" (2'8" wide with holddowns) described in
> 2320.11.4 of the 2001 California Building Code (based on the 1997
> UBC). No mention of doubling the boundary 2x4s is made in that
> paragraph; is that an implicit requirement, or does it not apply?
>
> The downside of doubling the boundary 2x4s, of course, is that it
> makes the holddowns 3" closer together, shortening the base of
> support, so perhaps the boundary 2x4s are supposed to be single
> members.
>

The "squash" posts can be a single 2x if it will take the compression
load. In most instances the use of 2-2x comes from the type of hold-down
used. In other words, it is the shear value on the hold-down fasteners
that typically governs the requirement for a double stud. If you are
using a strap type hold-down that is less than 1-1/2" wide then a single
2x should suffice.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

Wayne Whitney

2006-04-17, 11:21 pm

On 2006-04-17, Bob Morrison <SpamFighter@junk.com> wrote:

> You can use the trimmer or jack stud as part of your "squash" post. This
> will be a little situation dependent, but for a door it is not a problem
> since the jack stud is usually almost as long as the king stud.

OK, just to be clear--suppose the braced wall panel next to the
opening requires a double 2x4 for its squash posts. This could be
because (a) the hold down hardware requires more than a single 2x4 to
attach to, or (b) the design tension load in the squash post exceeds
the capacity of a single 2x4.

In case (b), do I understand correctly that if one of the 2x4s of the
squash post is used as a jack stud of the opening, some method to
transfer the tension load from above to the jack stud must be devised?
E.g., a metal strap connecting the cripple stud above to the jack
stud. Or if a holddown from above is used, keeping the holddown low
enough to connect directly to the jack stud, if feasible.

In case (a), if there is a holddown from above that requires a double
2x4, is it really OK just to attach it to the king stud and the
cripple stud?

Thanks, Wayne

Bob Morrison

2006-04-18, 12:21 am

In a previous post Wayne Whitney wrote...
> OK, just to be clear--suppose the braced wall panel next to the
> opening requires a double 2x4 for its squash posts. This could be
> because (a) the hold down hardware requires more than a single 2x4 to
> attach to, or (b) the design tension load in the squash post exceeds
> the capacity of a single 2x4.
>
> In case (b), do I understand correctly that if one of the 2x4s of the
> squash post is used as a jack stud of the opening, some method to
> transfer the tension load from above to the jack stud must be devised?
> E.g., a metal strap connecting the cripple stud above to the jack
> stud. Or if a holddown from above is used, keeping the holddown low
> enough to connect directly to the jack stud, if feasible.
>
> In case (a), if there is a holddown from above that requires a double
> 2x4, is it really OK just to attach it to the king stud and the
> cripple stud?
>

If the king/trimmer (jack) stud assembly below is connected to a hold-down
(or as I like to call them "floor-to-floor tie (FTF)") from above, then
the load must be fully transferred. So, with a strap type FTF, the strap
must extend the required distance below the top of the trimmer to develop
the full strength. For a bolt-type FTF (or hold-down) the hardware must
be mounted below the top of the trimmer.

If you can open a DWG file I can send you a detail of how this works. Or
I can turn the detail into a PDF and send. Let me know.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

Wayne Whitney

2006-04-18, 1:21 pm

On 2006-04-18, Bob Morrison <SpamFighter@junk.com> wrote:

> If the king/trimmer (jack) stud assembly below is connected to a hold-down
> (or as I like to call them "floor-to-floor tie (FTF)") from above, then
> the load must be fully transferred.

OK, that was my understanding. Academic question: if the header is
low in the wall, would it be reasonable to do the FTF tie to the
cripple stud above the jack stud, and then to use a FTF-type tie to
connect the jack stud and cripple stud around the header?

> If you can open a DWG file I can send you a detail of how this
> works. Or I can turn the detail into a PDF and send. Let me know.

Either one works for me, although I'm more used to PDF.

Thanks, Wayne

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