I got my pressure treated stringer boards, today. I had no idea they would
be so heavy. I bought 16 footers, cut in half for easy transport. Damn, I
must be getting old. The finished stringers will be no more than 48" in
length. In light of the increased weight of the stringers, I'm even more
concerned on the method of mounting the steps to the deck. I've noticed
several methods, of which I'll try to relate.
One is this obvious method of a right angle bracket. I assume there is one
on each side of the stringer, staggered, of course (yes/no?):
http://www.easy2diy.com/cm/easy/diy_ht_3d_index.asp?page_id=35779940
Another is notching the stringer to rest on top of a "ledger", as shown in
Fig N:
http://www.diynetwork.com/diy/ho_decks/article/0,,diy_13946_2268633,00.htm
The method on my old deck is a lazy variation of the above ledger method,
only the stringer is not notched to rest ON the ledger. The ledger is cut
to fit between the stringers and the stringers are secured by 3" deck screws
run through the stringer into the ends of the inside ledger.
My lumber man offered another method usng long 2" wide galvanized straps. I
thought he said the straps were secured to the deck and hung down and
secured to the back and underside of the stringer, using short strap nails.
I'm still vague on this method. Maybe someone can elaborate.
Again, considering the surprising weight of the PT stringers, along with the
aged wood of the old deck, I am looking for most secure method of mounting
these monster steps. I'm thinking the right angle brackets along with the
notched stringer ON the ledger might be more than enough support.
Also, the lumber guy commented on how deck screws are brittle and tend to
break in any application other than downward. When removing the old treads,
I noticed several deck screw heads had rusted through and just spun in their
holes. In fact this old deck is assembled soley with 3" deck screws and a
handfull of lag bolts on stress-bearing joints. I guess this is why the
lumber guy recommended short fat strap nails. Being an old pre-nailgun 16
box n' hammer man, I'm kinda enamored with this newer kinder (I'm in no
hurry) screw gun technology. Since I've got a hot new screw gun, what might
be more appropriate fastener for secureing the vert surfaces in this
application?
Any and all advice will be much apreciated. Thank you.
nb
On Wed, 18 Mar 2009 11:50:20 -0700 (PDT), RicodJour
<[email protected]> wrote:
> If it is a rule, it's a bit stupid.
Not sure I can agree with that assessment. Your suggestion would
surely work in specific cases, but I'm sure you'll agree that a board
with a defect/knot in one edge should not carry the same grade as one
with a small, tight knot centered in the board. Grades also specify a
maximum ratio of defect width to board width.
Ripping the board could easily place the defect too close to an edge
and/or increase the width ratio above the maximum for the grade. The
rule invalidating the construction grade when the board is ripped is,
IMO, a good rule.
Tom Veatch
Wichita, KS
USA
notbob wrote:
> Another is notching the stringer to rest on top of a "ledger", as shown in
> Fig N:
> http://www.diynetwork.com/diy/ho_decks/article/0,,diy_13946_2268633,00.htm
This is the only method I have any experience with. I'd be inclined to
have some concern about what happens with freeze/thaw heaving of the
ground the stringers rest on with the other methods...
> Any and all advice will be much apreciated. Thank you.
I'm not a carpenter or builder so you got from me pretty much what you
paid for. :)
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/
Limp Arbor wrote:
> On Mar 18, 1:01 pm, dpb <[email protected]> wrote:
>
>>Chris Friesen wrote:
>>
>>...> I'm assuming you meant thinnest here. In any case, this isn't the whole
>>
>>>picture, because the forces on the board are not uniform. Because of
>>>this, it makes a big difference where the thin point is.
>>
>>...
>>
>>You're right about effects but mixing comparisons between the strength
>>of the material and the loading effects of bending moment, etc.
>>
>>As noted above also in the particular case the actual relevant dimension
>>isn't the vertical distance above the ledger but the width across the
>>span normal to the length which is almost equivalent to the minimum
>>depth at the riser notch.
>>
>>--
>
>
> Maybe you guys are right but I was looking at it like this
> (use fixed font to view)
> The dotted lined represents the *thinnest* part of the stringer so it
> would only be as strong as a 2x4.
> (kind of tough to draw)
>
> /\ /\ /\
> / \ / \ / \
> / \/ \/ /
> \ ..................... /
> \/\ ________________/
> notch
> for ledger
>
>
> Of course it is never caryying a load at this angle so I am sure it
> isn't as simple as I think and I've seen lots of stairs made this way
> so it is probably fine. However I came across something that I never
> heard before and would like see what the group thinks.
>
> http://books.google.com/books?id=r5o7DSTahgwC&pg=PA182&lpg=PA182&dq=notch+joist+reduce+capacity&source=bl&ots=XAWN_cIn2B&sig=Tsum7IB0UKAgCdtoJF-zy4MRP_Y&hl=en&ei=ATLBSa2iIozhtge8uoTTCg&sa=X&oi=book_result&resnum=4&ct=result
> or
> http://tinyurl.com/c3gdew
>
> Last paragraph on page 182 states:
> "Ripping wide dimension lumber lowers the grade of the material and is
> unacceptable under all building codes"
>
> If this is true why is it true?
>
> Is it because of the location of possible defects like knots? If not
> for the notty knots why can't I rip a 2x12 down to a 2x10 and use it?
>
I only read the paragraph you cited but my guess is they are saying you
can't rip a floor joist where the final dimension would be less than
that as engineered and specified on the building plan
--
Jack Novak
Buffalo, NY - USA
[email protected]
notbob wrote:
> Also, the lumber guy commented on how deck screws are brittle and tend to
> break in any application other than downward.
Screws are available in varying quality. Better ones are not brittle.
For shear loads you want to size them such that the shank of the screw
is the same size as the nail you would have used.
Chris
In article <[email protected]>, notbob <[email protected]> wrote:
>I got my pressure treated stringer boards, today. I had no idea they would
>be so heavy. I bought 16 footers, cut in half for easy transport. Damn, I
>must be getting old. The finished stringers will be no more than 48" in
>length. In light of the increased weight of the stringers, I'm even more
>concerned on the method of mounting the steps to the deck.
Don't worry about the weight -- they're heavy because they're soaking wet.
Once they dry out, they'll be much lighter. Lumber is pressure-treated with a
water-borne preservative solution forced deep into the wood under high
pressure. It takes a *long* time for all that water to evaporate.
Limp Arbor wrote:
> Forget the ledger method. Look at the stringer, once you account for
> the notch for the risers and treads and the notch for the ledger you
> are effectively building your stairs on a 2x4.
Is this actually problem, given that it's only at one end of the
stairs? It takes a fair bit of force to shear off a 2x4, and you'd
still have the full width for the rest of the stairway to provide stiffness.
Chris
When we lived in the redwood mountains out west - our deck was 30+ feet
high. The stairs were on brackets like this. We had 4 landings on the
way down several were nice outlooks. One between several tall trees.
Typically they were nailed - special short nails that are really tough.
Then a lag bolt or two on each side.
Allow for expansion and shrinkage. Water expands wood and sun shrinks.
Wet wood shrinks. Doubt if you use kiln dry deck wood.
Martin
Morris Dovey wrote:
> notbob wrote:
>
>> Another is notching the stringer to rest on top of a "ledger", as
>> shown in
>> Fig N:
>> http://www.diynetwork.com/diy/ho_decks/article/0,,diy_13946_2268633,00.htm
>>
>
> This is the only method I have any experience with. I'd be inclined to
> have some concern about what happens with freeze/thaw heaving of the
> ground the stringers rest on with the other methods...
>
>> Any and all advice will be much apreciated. Thank you.
>
> I'm not a carpenter or builder so you got from me pretty much what you
> paid for. :)
>
On Mar 18, 2:00=A0pm, Limp Arbor <[email protected]> wrote:
> On Mar 18, 1:01=A0pm, dpb <[email protected]> wrote:
>
>
>
> > Chris Friesen wrote:
>
> > ...> I'm assuming you meant thinnest here. =A0In any case, this isn't t=
he whole
> > > picture, because the forces on the board are not uniform. =A0Because =
of
> > > this, it makes a big difference where the thin point is.
>
> > ...
>
> > You're right about effects but mixing comparisons between the strength
> > of the material and the loading effects of bending moment, etc.
>
> > As noted above also in the particular case the actual relevant dimensio=
n
> > isn't the vertical distance above the ledger but the width across the
> > span normal to the length which is almost equivalent to the minimum
> > depth at the riser notch.
>
> > --
>
> Maybe you guys are right but I was looking at it like this
> (use fixed font to view)
> The dotted lined represents the *thinnest* part of the stringer so it
> would only be as strong as a 2x4.
> (kind of tough to draw)
>
> =A0 =A0 /\ =A0 =A0 =A0 =A0/\ =A0 =A0 =A0 =A0/\
> =A0 / =A0 =A0\ =A0 =A0/ =A0 =A0\ =A0 =A0/ =A0 =A0\
> / =A0 =A0 =A0 =A0\/ =A0 =A0 =A0 =A0\/ =A0 =A0 /
> \ ..................... /
> =A0 \/\ ________________/
> notch
> for ledger
>
> Of course it is never caryying a load at this angle so I am sure it
> isn't as simple as I think and I've seen lots of stairs made this way
> so it is probably fine. =A0However I came across something that I never
> heard before and would like see what the group thinks.
>
> http://books.google.com/books?id=3Dr5o7DSTahgwC&pg=3DPA182&lpg=3DPA182&dq=
=3Dn...
> orhttp://tinyurl.com/c3gdew
>
> Last paragraph on page 182 states:
> "Ripping wide dimension lumber lowers the grade of the material and is
> unacceptable under all building codes"
>
> If this is true why is it true?
>
> Is it because of the location of possible defects like knots? =A0If not
> for the notty knots why can't I rip a 2x12 down to a 2x10 and use it?
I'd never heard of that rule, but I'm sure the location of knots has
everything to do with it. If it is a rule, it's a bit stupid. You're
only going to be ripping one side, so put the ripped side on the
compression side and it's no longer a concern.
R
On Mar 18, 10:17=A0am, Chris Friesen <[email protected]> wrote:
> Limp Arbor wrote:
> > Forget the ledger method. =A0Look at the stringer, once you account for
> > the notch for the risers and treads and the notch for the ledger you
> > are effectively building your stairs on a 2x4.
>
> Is this actually =A0problem, given that it's only at one end of the
> stairs? =A0It takes a fair bit of force to shear off a 2x4, and you'd
> still have the full width for the rest of the stairway to provide stiffne=
ss.
>
> Chris
A chain is only as strong as it's weakest link and a board is only as
strong as it's thickest point.
In reality probably not a problem but why do it when there are simple
brackets available that will do a better job.
On Mar 18, 10:17=A0am, Chris Friesen <[email protected]> wrote:
> Limp Arbor wrote:
>
> > Forget the ledger method. =A0Look at the stringer, once you account for
> > the notch for the risers and treads and the notch for the ledger you
> > are effectively building your stairs on a 2x4.
>
> Is this actually =A0problem, given that it's only at one end of the
> stairs? =A0It takes a fair bit of force to shear off a 2x4, and you'd
> still have the full width for the rest of the stairway to provide stiffne=
ss.
The 2x4 is obviously strong enough to carry the stair load. Most
stringers end up with only a few inches of "beam".
The OP shouldn't be worried about the dead load of the steps. The
live load is much more critical.
A ledger doesn't have to be a 2x4 - a 2x3 or even 2x2 will work. If
you want to do a belt and suspenders, and you don't mind the exposed
metal, omit the ledger and use joist hangers. A joist hanger can
carry one half of the load of a full length floor joist, so it will
certainly carry any load you can put on those steps.
R
On Mar 18, 1:01=A0pm, dpb <[email protected]> wrote:
> Chris Friesen wrote:
>
> ...> I'm assuming you meant thinnest here. =A0In any case, this isn't the=
whole
> > picture, because the forces on the board are not uniform. =A0Because of
> > this, it makes a big difference where the thin point is.
>
> ...
>
> You're right about effects but mixing comparisons between the strength
> of the material and the loading effects of bending moment, etc.
>
> As noted above also in the particular case the actual relevant dimension
> isn't the vertical distance above the ledger but the width across the
> span normal to the length which is almost equivalent to the minimum
> depth at the riser notch.
>
> --
Maybe you guys are right but I was looking at it like this
(use fixed font to view)
The dotted lined represents the *thinnest* part of the stringer so it
would only be as strong as a 2x4.
(kind of tough to draw)
/\ /\ /\
/ \ / \ / \
/ \/ \/ /
\ ..................... /
\/\ ________________/
notch
for ledger
Of course it is never caryying a load at this angle so I am sure it
isn't as simple as I think and I've seen lots of stairs made this way
so it is probably fine. However I came across something that I never
heard before and would like see what the group thinks.
http://books.google.com/books?id=3Dr5o7DSTahgwC&pg=3DPA182&lpg=3DPA182&dq=
=3Dnotch+joist+reduce+capacity&source=3Dbl&ots=3DXAWN_cIn2B&sig=3DTsum7IB0U=
KAgCdtoJF-zy4MRP_Y&hl=3Den&ei=3DATLBSa2iIozhtge8uoTTCg&sa=3DX&oi=3Dbook_res=
ult&resnum=3D4&ct=3Dresult
or
http://tinyurl.com/c3gdew
Last paragraph on page 182 states:
"Ripping wide dimension lumber lowers the grade of the material and is
unacceptable under all building codes"
If this is true why is it true?
Is it because of the location of possible defects like knots? If not
for the notty knots why can't I rip a 2x12 down to a 2x10 and use it?
On Mar 18, 9:57=A0am, [email protected] (Doug Miller) wrote:
> In article <[email protected]>, notbob <[email protected]=
om> wrote:
> >I got my pressure treated stringer boards, today. =A0I had no idea they =
would
> >be so heavy. =A0I bought 16 footers, cut in half for easy transport. =A0=
Damn, I
> >must be getting old. =A0The finished stringers will be no more than 48" =
in
> >length. =A0In light of the increased weight of the stringers, I'm even m=
ore
> >concerned on the method of mounting the steps to the deck.
>
> Don't worry about the weight -- they're heavy because they're soaking wet=
.
> Once they dry out, they'll be much lighter. Lumber is pressure-treated wi=
th a
> water-borne preservative solution forced deep into the wood under high
> pressure. It takes a *long* time for all that water to evaporate.
Poor quality pressure-treated lumber is soaking wet. Quality lumber
is kiln dried, treated in a pressure chamber and then dried again.
On Mar 18, 5:40=A0am, notbob <[email protected]> wrote:
> I got my pressure treated stringer boards, today. =A0I had no idea they w=
ould
> be so heavy. =A0I bought 16 footers, cut in half for easy transport. =A0D=
amn, I
> must be getting old. =A0The finished stringers will be no more than 48" i=
n
> length. =A0In light of the increased weight of the stringers, I'm even mo=
re
> concerned on the method of mounting the steps to the deck. =A0I've notice=
d
> several methods, of which I'll try to relate.
>
> One is this obvious method of a right angle bracket. =A0I assume there is=
one
> on each side of the stringer, staggered, of course (yes/no?):http://www.e=
asy2diy.com/cm/easy/diy_ht_3d_index.asp?page_id=3D35779940
>
> Another is notching the stringer to rest on top of a "ledger", as shown i=
n
> Fig N:http://www.diynetwork.com/diy/ho_decks/article/0,,diy_13946_2268633=
,0...
>
> The method on my old deck is a lazy variation of the above ledger method,
> only the stringer is not notched to rest ON the ledger. =A0The ledger is =
cut
> to fit between the stringers and the stringers are secured by 3" deck scr=
ews
> run through the stringer into the ends of the inside ledger.
>
> My lumber man offered another method usng long 2" wide galvanized straps.=
=A0I
> thought he said the straps were secured to the deck and hung down and
> secured to the back and underside of the stringer, using short strap nail=
s.
> I'm still vague on this method. =A0Maybe someone can elaborate.
>
> Again, considering the surprising weight of the PT stringers, along with =
the
> aged wood of the old deck, I am looking for most secure method of mountin=
g
> these monster steps. =A0I'm thinking the right angle brackets along with =
the
> notched stringer ON the ledger might be more than enough support. =A0
>
> Also, the lumber guy commented on how deck screws are brittle and tend to
> break in any application other than downward. =A0When removing the old tr=
eads,
> I noticed several deck screw heads had rusted through and just spun in th=
eir
> holes. =A0In fact this old deck is assembled soley with 3" deck screws an=
d a
> handfull of lag bolts on stress-bearing joints. =A0I guess this is why th=
e
> lumber guy recommended short fat strap nails. =A0Being an old pre-nailgun=
16
> box n' hammer man, I'm kinda enamored with this newer kinder (I'm in no
> hurry) screw gun technology. =A0Since I've got a hot new screw gun, what =
might
> be more appropriate fastener for secureing the vert surfaces in this
> application?
>
> Any and all advice will be much apreciated. =A0Thank you.
>
> nb
Go to page 14 of this pdf.
http://www.strongtie.com/ftp/fliers/f-deckcode07.pdf
These usually get attached with short fat galvanized nails. Once you
fill every hole with a nail, those stringers aren't going anywhere.
Should be available at almost any lumber yard, either Lowes or HD
doesn't sell Simpson but the other does.
Forget the ledger method. Look at the stringer, once you account for
the notch for the risers and treads and the notch for the ledger you
are effectively building your stairs on a 2x4.
Limp Arbor wrote:
...
> Forget the ledger method. Look at the stringer, once you account for
> the notch for the risers and treads and the notch for the ledger you
> are effectively building your stairs on a 2x4.
No. Even though the notch in that figure in order to match top of
stringer to proper height is larger than the minimum possible by using a
2x4 ledger (instead of 2x3 or 2x2), the pertinent dimension for the
width of bearing on the stringer is the distance from the notch corner
_PERPENDICULAR_ to the length of the stringer, not the vertical
distance. That distance isn't significantly less than the depth of the
stringer at the notches so there isn't any less strength at the end than
in the middle.
--
Chris Friesen wrote:
...
> I'm assuming you meant thinnest here. In any case, this isn't the whole
> picture, because the forces on the board are not uniform. Because of
> this, it makes a big difference where the thin point is.
...
You're right about effects but mixing comparisons between the strength
of the material and the loading effects of bending moment, etc.
As noted above also in the particular case the actual relevant dimension
isn't the vertical distance above the ledger but the width across the
span normal to the length which is almost equivalent to the minimum
depth at the riser notch.
--
In news:[email protected],
Chris Friesen <[email protected]> dropped this bit of wisdom:
> notbob wrote:
>=20
>> Also, the lumber guy commented on how deck screws are brittle and
>> tend to break in any application other than downward.
>=20
> Screws are available in varying quality. Better ones are not brittle.
>=20
> For shear loads you want to size them such that the shank of the screw
> is the same size as the nail you would have used.
>=20
> Chris
And, if you are going to use screws, use _stainless_ as other coated =
and dipped nails and screws will do exactly what the old screws on your =
deck did - rust off. =20
P D Q
"Limp Arbor" <[email protected]> wrote in message
news:cb8295bf-318a-49ed-8702-90633c4f89f6@a39g2000yqc.googlegroups.com...
On Mar 18, 10:17 am, Chris Friesen <[email protected]> wrote:
> Limp Arbor wrote:
> > Forget the ledger method. Look at the stringer, once you account for
> > the notch for the risers and treads and the notch for the ledger you
> > are effectively building your stairs on a 2x4.
>
> Is this actually problem, given that it's only at one end of the
> stairs? It takes a fair bit of force to shear off a 2x4, and you'd
> still have the full width for the rest of the stairway to provide
> stiffness.
>
> Chris
A chain is only as strong as it's weakest link and a board is only as
strong as it's thickest point.
In reality probably not a problem but why do it when there are simple
brackets available that will do a better job.
Limp Arbor,
I suspect you meant "thinnest", yes?
Kerry
Limp Arbor wrote:
> A chain is only as strong as it's weakest link and a board is only as
> strong as it's thickest point.
I'm assuming you meant thinnest here. In any case, this isn't the whole
picture, because the forces on the board are not uniform. Because of
this, it makes a big difference where the thin point is.
If the thin point is in the middle, it will reduce the stiffness and
strength greatly due to the decreased moment of inertia at the point of
greatest stress. If the thin point is at either end it will have little
impact on the stiffness and the decreased shear strength is not going to
matter in this application.
This same principle is why you're not supposed to notch solid floor
joists in the middle third of the span.
Chris