I'm installing 5/8' underlayment over a 1/2" subfloor. I've seen
contradicting info on how to orient the underlayment. Some say right
angles to the subfloor, but some say right angles to the joists. I
cant have it both ways, since my subfloor was installed at right
angles to the joists. What to do? My previous underlayment (which I
removed) was laid across the joists so unless I can find a compelling
reason I guess I'll redo it that way.

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?

On Wed, 14 Oct 2009 17:09:19 -0700 (PDT), Joe
wrote:

I'm installing 5/8' underlayment over a 1/2" subfloor. I've seen
contradicting info on how to orient the underlayment. Some say right
angles to the subfloor, but some say right angles to the joists. I
cant have it both ways, since my subfloor was installed at right
angles to the joists. What to do? My previous underlayment (which I
removed) was laid across the joists so unless I can find a compelling
reason I guess I'll redo it that way.

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?



How long will a 1 inch nail hold a 5/8" material?

Oren wrote in news:kgqcd5psggthgm97jjpi7hq7ka4m4ut8j8@
4ax.com:

On Wed, 14 Oct 2009 17:09:19 -0700 (PDT), Joe
wrote:

I'm installing 5/8' underlayment over a 1/2" subfloor. I've seen
contradicting info on how to orient the underlayment. Some say right
angles to the subfloor, but some say right angles to the joists. I
cant have it both ways, since my subfloor was installed at right
angles to the joists. What to do? My previous underlayment (which I
removed) was laid across the joists so unless I can find a compelling
reason I guess I'll redo it that way.

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?



How long will a 1 inch nail hold a 5/8" material?


1 x 5/8 x 12mo = 7.5 months.

On Oct 14, 7:19*pm, Oren wrote:
On Wed, 14 Oct 2009 17:09:19 -0700 (PDT), Joe
wrote:



I'm installing 5/8' underlayment over a 1/2" subfloor. I've seen
contradicting info on how to orient the underlayment. *Some say right
angles to the subfloor, but some say right angles to the joists. I
cant have it both ways, since my subfloor was installed at right
angles to the joists. What to do? My previous underlayment (which I
removed) was laid across the joists so unless I can find a compelling
reason I guess I'll redo it that way.

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?

How long will a 1 inch nail hold a 5/8" material?

I'd guess about exactly as long a 1 1/4 inch nail that chips out 1/8"
of the 1/2" subfloor.

"Joe" wrote in message
...
I'm installing 5/8' underlayment over a 1/2" subfloor. I've seen
contradicting info on how to orient the underlayment. Some say right
angles to the subfloor, but some say right angles to the joists. I
cant have it both ways, since my subfloor was installed at right
angles to the joists. What to do? My previous underlayment (which I
removed) was laid across the joists so unless I can find a compelling
reason I guess I'll redo it that way.

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?




First of all I don't consider 5/8" over 1/2" to be under-layment at all.
That is called a floor. Half inch is nothing.

Under-layment is something you put down to provide a smooth clean surface
for tile or vinyl and can be run either way. Usually it 1/4" and added to at
least a 3/4" sub-floor.

I would install it with the 8' running across the joist and try my darnest
to hit the joists. I would stagger the seams so that the new does not line
up with the old on either direction. I would use a minimum of 8D sinkers to
secure it. Now you have a floor.

To minimize potential squeaks I would use a single layer of 30# felt or a
double layer of 15# felt. Alternately you can use liquid nails or the like
in lieu of the felt.


--
Colbyt
Please come visit www.househomerepair.com

On Wed, 14 Oct 2009 18:40:54 -0700 (PDT), Joe
wrote:

On Oct 14, 7:19*pm, Oren wrote:
On Wed, 14 Oct 2009 17:09:19 -0700 (PDT), Joe
wrote:



I'm installing 5/8' underlayment over a 1/2" subfloor. I've seen
contradicting info on how to orient the underlayment. *Some say right
angles to the subfloor, but some say right angles to the joists. I
cant have it both ways, since my subfloor was installed at right
angles to the joists. What to do? My previous underlayment (which I
removed) was laid across the joists so unless I can find a compelling
reason I guess I'll redo it that way.

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?

How long will a 1 inch nail hold a 5/8" material?

I'd guess about exactly as long a 1 1/4 inch nail that chips out 1/8"
of the 1/2" subfloor.


I'm sorry as I'm not certain what you mean by "chips out".

Dangling attic roofing nails can get your suspenders caught on the
nail or a hole-in-the-head. Those nails splinter the wood.

"Joe" wrote in message

Also, I want to use nails. Screws are just plain out of the question,
and I dont want the expense of renting or buying staple equipment. But
the shortest ring shank underlayment nails are 1 1/4", which means
every one will be punching a hole and splintering out the bottom of my
subfloor, which is not desirable. I know they make 25 mm (1 inch)
underlayment nails but I cant find them in the US (or Canada, so
far)..

What to do?

I think you're screwed. Neihter McFeelys nor McMaster have them so they will
be about impossible to find. I'd buy or rent a stapler. Or go with screws.

http://www.halexcorp.com/halex_underlayment_3.shtml

Fasten the plywood underlayment panels securely to a structurally sound,
smooth, clean and dry subfloor using;

a.. Staples: galvanized or polymer coated 18 gauge chisel point staples
with minimum 1/4" crown or,

b.. Galvanized ring shank flooring nails: 12 gauge, minimum 3/16" diameter
head or,

c.. Galvanized flat head wood screws.
Fasteners should be long enough to penetrate through the plywood
underlayment and atleast 80-95% of the subfloor, but not protrude through
the bottom. Fasten one plywood underlayment panel at a time, starting from
one side and working to the other. Do not lack the corners first. If using
staples or nails, fasten on every fastener mark (4" on center in the field
and 2" on center along all edges. Fasten edges 3/8" - 1/2" from the edge.
Fasteners should be set flush so they do not protrude above the plywood
underlayment.

"Colbyt" wrote:

-snip-

First of all I don't consider 5/8" over 1/2" to be under-layment at all.
That is called a floor. Half inch is nothing.

Under-layment is something you put down to provide a smooth clean surface
for tile or vinyl and can be run either way. Usually it 1/4" and added to at
least a 3/4" sub-floor.

I would install it with the 8' running across the joist and try my darnest
to hit the joists. I would stagger the seams so that the new does not line
up with the old on either direction. I would use a minimum of 8D sinkers to
secure it. Now you have a floor.

To minimize potential squeaks I would use a single layer of 30# felt or a
double layer of 15# felt. Alternately you can use liquid nails or the like
in lieu of the felt.

What he said. Though he didn't make clear that all those 8D nails
go into joists.

*THEN* you put your 1/4 subfloor in if you need it and use the short
ring nails.

Jim

On Oct 15, 5:52*am, Jim Elbrecht wrote:
"Colbyt" wrote:

-snip-





First of all I don't consider 5/8" over 1/2" to be under-layment at all.
That is called a floor. *Half inch is nothing.

Under-layment is something you put down to provide a smooth clean surface
for tile or vinyl and can be run either way. Usually it 1/4" and added to at
least a 3/4" sub-floor.

I would install it *with the 8' running across *the joist and try my darnest
to hit the joists. *I would stagger the seams so that the new does not line
up with the old on either direction. I would use a minimum of 8D sinkers to
secure it. Now you have a floor.

To minimize potential squeaks I would use a single layer of 30# *felt or a
double layer of 15# felt. Alternately you can use liquid nails or the like
in lieu of the felt.

What he said. * * Though he didn't make clear that all those 8D nails
go into joists.

*THEN* you put your 1/4 subfloor in if you need it and use the short
ring nails.

Jim

I already have a subfloor. The subfloor goes on the joists.
Underlayment goes on top of the subfloor.

On Thu, 15 Oct 2009 07:49:33 -0700 (PDT), Joe
wrote:

On Oct 15, 5:52*am, Jim Elbrecht wrote:

-snip-

*THEN* you put your 1/4 subfloor in if you need it and use the short
ring nails.

Jim

I already have a subfloor. The subfloor goes on the joists.
Underlayment goes on top of the subfloor.

Brainfart- sorry. I meant underlayment. I don't consider 1/2 ply
to be anything more than a waste of time. 5/8, maybe-- but I
wouldn't do less than a couple layers of 3/4. I'd even prefer
shiplap for that first layer over the joists. Then 3/4 T&G to
smooth things out.

Jim

On Oct 15, 10:49*am, Joe wrote:
On Oct 15, 5:52*am, Jim Elbrecht wrote:
"Colbyt" wrote:

First of all I don't consider 5/8" over 1/2" to be under-layment at all.
That is called a floor. *Half inch is nothing.

Under-layment is something you put down to provide a smooth clean surface
for tile or vinyl and can be run either way. Usually it 1/4" and added to at
least a 3/4" sub-floor.

I would install it *with the 8' running across *the joist and try my darnest
to hit the joists. *I would stagger the seams so that the new does not line
up with the old on either direction. I would use a minimum of 8D sinkers to
secure it. Now you have a floor.

To minimize potential squeaks I would use a single layer of 30# *felt or a
double layer of 15# felt. Alternately you can use liquid nails or the like
in lieu of the felt.

Squeaks come from the wood sliding against the nails, not from the
underlayment sliding against the subfloor.

What he said. * * Though he didn't make clear that all those 8D nails
go into joists.

*THEN* you put your 1/4 subfloor in if you need it and use the short
ring nails.

Jim

I already have a subfloor. The subfloor goes on the joists.
Underlayment goes on top of the subfloor.

Thanks for the definitions. He used the wrong word, so stop being a
smartass and learn something.

"Screws are just plain out of the question"...? Why? It's a superior
installation, doesn't cost a hell of a lot more, and unless you're
doing an entire house won't take all that much more time. Even if you
are doing a whole house, the superior installation is worth the time
and money. Rent an autofeed screwgun if you're worried about the
time.

If you are going to use nails, you should know what nails do, and how
they are supposed to work. Underlayment nails, and roofing nails, are
designed to penetrate completely through the wood sheathing. They
hold much better that way and are far less likely to back out over
time. If you are concerned about the appearance from below (you like
the look of exposed 1/2" CDX???), then you should look into nailing
just at the joists, glue the underlayment down and weight it so there
are no gaps between the two layers.

R

Thanks for the definitions. *He used the wrong word, so stop being a
smartass and learn something.

I wasnt being a smartass. It seemed he was suggesting that I install a
3rd layer. I already have a subfloor. He agreed with the other poster
that I should install my 5/8 across the joists, and then suggested I
install a 1/4 inch on top of that. Nobody suggested taking out the 1/2
inch subfloor, which is good because I have no intention of doing so.
But I certainly dont need 3 layers.


"Screws are just plain out of the question"...? *Why?

Because after reading about the pros and cons I decided I'm not using
screws. I might shoot one in here and there
if necessary.

*It's a superior
installation, doesn't cost a hell of a lot more, and unless you're
doing an entire house won't take all that much more time. *Even if you
are doing a whole house, the superior installation is worth the time
and money. *Rent an autofeed screwgun if you're worried about the
time.

If you are going to use nails, you should know what nails do, and how
they are supposed to work. *Underlayment nails, and roofing nails, are
designed to penetrate completely through the wood sheathing. *They
hold much better that way and are far less likely to back out over
time.

I have read the exact opposite. They should not penetrate the
subfloor. That was posted above and I have read it in other places. I
have also read the opposite, but since nails penetrating the subfloor
will splinter (or chip) the bottom and reduce holding power it seems
wise to me not to penetrate it completely if possible. I may not have
a choice though, if I use 5/8 plywood and nails.

On Oct 15, 1:47*pm, Joe wrote:
Thanks for the definitions. *He used the wrong word, so stop being a
smartass and learn something.

I wasnt being a smartass. It seemed he was suggesting that I install a
3rd layer. I already have a subfloor. He agreed with the other poster
that I should install my 5/8 across the joists, and then suggested I
install a 1/4 inch on top of that. Nobody suggested taking out the 1/2
inch subfloor, which is good because I have no intention of doing so.
But I certainly dont need 3 layers.

You're dicking around with trying to improve something that is
substandard. Don't. Bite the bullet and just put down a 3/4"
subfloor on top of what you've got, then it doesn't matter what you've
got and you don't have to worry about attaching the layers. The price
difference is small and the savings in not having to mess around with
underlayment nails and worrying about attaching two layers is
obviously worth it.

"Screws are just plain out of the question"...? *Why?

Because after reading about the pros and cons I decided I'm not using
screws. I might shoot one in here and there
if necessary.

Cons? Okay, other than a worthwhile bump up in cost, and taking a bit
more time, name the cons.

*It's a superior

installation, doesn't cost a hell of a lot more, and unless you're
doing an entire house won't take all that much more time. *Even if you
are doing a whole house, the superior installation is worth the time
and money. *Rent an autofeed screwgun if you're worried about the
time.

If you are going to use nails, you should know what nails do, and how
they are supposed to work. *Underlayment nails, and roofing nails, are
designed to penetrate completely through the wood sheathing. *They
hold much better that way and are far less likely to back out over
time.

I have read the exact opposite. They should not penetrate the
subfloor. That was posted above and I have read it in other places. I
have also read the opposite, but since nails penetrating the subfloor
will splinter (or chip) the bottom and reduce holding power it seems
wise to me not to penetrate it completely if possible. I may not have
a choice though, if I use 5/8 plywood and nails.

Yeah, you read. There's a lot of bad information out there, and you
went and got yourself some. Attaching underlayment is essentially the
same as attaching roof shingles, and the nails are intended to perform
similarly. Plywood does not have the nail holding power that solid
sawn lumber does. If you had an old-school shiplapped subfloor, 3/4"
to 7/8" thick, then the underlayment nail doesn't have to penetrate
fully. You don't, so they do.

SBC further specifies that fasteners
for asphalt shingles be "minimum 12-
gauge (0.105-inch [2.67-mm]) shank
with minimum %-inch [10-mm] di-
ameter head, of a length to penetrate
through the roofing materials and a
minimum of % inch (19 mm) into the
roof sheathing. Where the roof sheath-
ing is less than % inch (19 mm) thick,
the nails shall penetrate through the
sheathing."

R

"Joe" wrote in message
...

But I certainly dont need 3 layers.




Joe you came here asking for advice and you are getting some from people who
really have done this a few times.

Allow me to define some terms.
A sub-floor is anything that is not finishable. No matter how many layers of
plywood you put down it is all subfloor.
Half inch plwood is not a suitable surface to nail or screw anything to if
you want it to last. You need to hit the joists with your 8D nails. You are
wasting you time worring about stuff that isn't going to last no matter what
you do or don't.

You might very well need 3 layers if you plan on using vinyl tile or sheet
goods because unsanded (very smooth) plywood is not an acceptable base for
either.

You can carpet over the sub-floor as defined above. You might get away with
the new loose-lay vinyl over a tightly fitted top layer of smooth plywood.

I have a 3/4" T&G plywood sub-floor with 16" OC joists in a 1995 house.
Most of the downstairs has 3/4" hardwood over that. Every darn hardwood
nail that did not hit a joist penetrated the subfloor.

Roofing nails are meant to penetrate the deck by at least 1/8" (per mfg
instructions).

Good luck with your project.


Colbyt

On Thu, 15 Oct 2009 11:30:20 -0700 (PDT), RicodJour
wrote:

You're dicking around with trying to improve something that is
substandard. Don't. Bite the bullet and just put down a 3/4"
subfloor on top of what you've got, then it doesn't matter what you've
got and you don't have to worry about attaching the layers. The price
difference is small and the savings in not having to mess around with
underlayment nails and worrying about attaching two layers is
obviously worth it.

LOL!

On Wed, 14 Oct 2009 18:40:54 -0700 (PDT), Joe
wrote:

How long will a 1 inch nail hold a 5/8" material?

I'd guess about exactly as long a 1 1/4 inch nail that chips out 1/8"
of the 1/2" subfloor.

Sorry, I cannot accept that.

On Oct 15, 3:33*pm, "Colbyt" wrote:
"Joe" wrote in message


But I certainly dont need 3 layers.

Joe you came here asking for advice and you are getting some from people who
really have done this a few times.

And I appreciate the advice. Nobody asked what my finish floor was
going to be but I already knew, and that might have avoided some
misunderstanding.

Allow me to define some terms.
A sub-floor is anything that is not finishable. No matter how many layers of
plywood you put down it is all subfloor.
Half inch plwood is not a suitable surface to nail or screw anything to if
you want it to last. You need to hit the joists with your 8D nails. You are
wasting you time worring about stuff that isn't going to last no matter what
you do or don't.

I didnt realize it but It appears that they only nailed the previous
5/8 into the joists-I didnt pay that close attention when I pulled it
up (it was particle board that had gotten wet, and it was a
nightmare), but I see now they didnt nail it in the field much, if at
all.



You might very well need 3 layers if you plan on using vinyl tile or sheet
goods because unsanded (very smooth) * plywood is not an acceptable base for
either.

You can carpet over the sub-floor as defined above. You might get away with
the new loose-lay vinyl over a tightly fitted top layer of smooth plywood..

Thats what i'm putting down, floating vinyl in one room and carpet in
the other. So it seems I dont have a problem anymore, I just nail
into the joists.

On Oct 15, 6:54*pm, Joe wrote:

I didnt realize it but It appears that they only nailed the previous
5/8 into the joists-I didnt pay that close attention when I pulled it
up (it was particle board that had gotten wet, and it was a
nightmare), but I see now they didnt nail it in the field much, if at
all.

Right, copy the failed installation. Seems like a plan.

R

On Oct 15, 7:05*pm, RicodJour wrote:
On Oct 15, 6:54*pm, Joe wrote:



I didnt realize it but It appears that they only nailed the previous
5/8 into the joists-I didnt pay that close attention when I pulled it
up (it was particle board that had gotten wet, and it was a
nightmare), but I see now they didnt nail it in the field much, if at
all.

Right, copy the failed installation. *Seems like a plan.

R

Failed? What failed?

"Joe" wrote in message
...

Thats what i'm putting down, floating vinyl in one room and carpet in
the other. So it seems I dont have a problem anymore, I just nail
into the joists.



Just remember to stagger all the joints in both directions. That might
think you think a bit.

And as long as you are not using particle board (which you aren't) you are
not following the failed installation.

On Oct 15, 9:19*pm, "Colbyt" wrote:
"Joe" wrote in message

Thats what i'm putting down, floating vinyl in one room and carpet in
the other. *So it seems I dont have a problem anymore, I just nail
into the joists.

Just remember to stagger all the joints in both directions. *That might
think you think a bit.

And as long as you are not using particle board (which you aren't) you are
not following the failed installation.

Perhaps you like unnecessary flexure in a floor, but can you really
countenance omitting a simple step that would improve the
installation? Instead of having the two layers bonded and acting as
one, you'd prefer to save on a few pounds of screws or nails?

R

On Oct 15, 8:53*pm, RicodJour wrote:
On Oct 15, 9:19*pm, "Colbyt" wrote:

"Joe" wrote in message

Thats what i'm putting down, floating vinyl in one room and carpet in
the other. *So it seems I dont have a problem anymore, I just nail
into the joists.

Just remember to stagger all the joints in both directions. *That might
think you think a bit.

And as long as you are not using particle board (which you aren't) you are
not following the failed installation.

Perhaps you like unnecessary flexure in a floor, but can you really
countenance omitting a simple step that would improve the
installation? *Instead of having the two layers bonded and acting as
one, you'd prefer to save on a few pounds of screws or nails?

R

The previous installation worked just fine except for the particle
board that got wet (so this one will be better). It isnt a simple
step to put down 2 layers instead of one but if it will make you happy
i will put some 1 1/4 ring shank nails in the field as well as nailing
it firmly to the joists. I have no problem with that. Otherwise I'm
not sure what you mean by omitting a simple step.

On Oct 16, 1:26*am, Joe wrote:
On Oct 15, 8:53*pm, RicodJour wrote:
On Oct 15, 9:19*pm, "Colbyt" wrote:
"Joe" wrote in message

Thats what i'm putting down, floating vinyl in one room and carpet in
the other. *So it seems I dont have a problem anymore, I just nail
into the joists.

Just remember to stagger all the joints in both directions. *That might
think you think a bit.

And as long as you are not using particle board (which you aren't) you are
not following the failed installation.

Perhaps you like unnecessary flexure in a floor, but can you really
countenance omitting a simple step that would improve the
installation? *Instead of having the two layers bonded and acting as
one, you'd prefer to save on a few pounds of screws or nails?


The previous installation worked just fine except for the particle
board *that got wet (so this one will be better). It isnt a simple
step to put down 2 layers instead of one but if it will make you happy
i will put some 1 1/4 ring shank nails in the field as well as nailing
it firmly to the joists. I have no problem with that. Otherwise I'm
not sure what you mean by omitting a simple step.

That is the simple step. You want the two layers to act as one -
monolithically. If you don't physically attach the two layers
together with glue/screws/nails the end result will not be nearly as
strong and stiff.

R