So I'm back with a question about my T&G wood floor in the converted garage. I was going to put 3/4 inch plywood down on the cement floor first, on top of a vapor barrier. How do I make sure the plywood stays down? One person says shoot 22-caliber nails, 6 or 8 per 4x8 sheet of plywood (he would lend me the gun), another says drill through the plywood into the cement and put in screws with those plastic anchors, because shooting in the nails might explode the cement. I'd be totally grateful to anyone sharing their experience with this.

Marianne

On May 11, 9:24 am, Marianne Halevi Marianne.Halevi.
wrote:
So I'm back with a question about my T&G wood floor in the converted
garage. I was going to put 3/4 inch plywood down on the cement floor
first, on top of a vapor barrier. How do I make sure the plywood stays
down? One person says shoot 22-caliber nails, 6 or 8 per 4x8 sheet of
plywood (he would lend me the gun), another says drill through the
plywood into the cement and put in screws with those plastic anchors,
because shooting in the nails might explode the cement. I'd be totally
grateful to anyone sharing their experience with this.

Marianne

--
Marianne Halevi

If you have a ROTARY HAMMER drill, not a hammer drill, then Tapcon
screws will work very well. Not the plastic anchor things you
mention. Tapcon screws bite into the concrete itself and hold well
enough for anything that is not subject to extreme forces. You don't
have to use lots and lots of Tapcon screws to hold the plywood down
since gravity will help considerably. Use the correct undersized
drill bit. Something like 5/32" drill for 3/16" screws I think.
Hammer drills are so slow and stop when hitting aggregate I cannot
stand to use them with Tapcon screws. I hate hammer drills. For
attaching electrical boxes to concrete walls, use the Tapcons with a
rotary hammer drill.

The powder actuated nails work very well and are very quick. Every
now and then you get blowout of the concrete. But not too often
really. You minimize this occassional problem considerably by firmly
pressing down on the wood being fastened to the concrete. For
attaching framing to floors and walls in basements, this is the method
to use. And any blowout is going to be underneath and hidden so you
will never see it or even know.

I would use the Tapcon screws. I think it's the most reasonably priced
method and it works really well. Rent a good rotary hammer drill if you
don't have one, buy the specified diameter bit for the size Tapcon screw
that you will be using (maybe a spare or two) and it will be an easy
installation. A good standard driver/drill will easily drive the screws in
once the holes have been drilled. Make sure that you drill the holes deeper
than the screws are long to allow for a debris pocket under the screw.

--
Charley


wrote in message
oups.com...
On May 11, 9:24 am, Marianne Halevi Marianne.Halevi.
wrote:
So I'm back with a question about my T&G wood floor in the converted
garage. I was going to put 3/4 inch plywood down on the cement floor
first, on top of a vapor barrier. How do I make sure the plywood stays
down? One person says shoot 22-caliber nails, 6 or 8 per 4x8 sheet of
plywood (he would lend me the gun), another says drill through the
plywood into the cement and put in screws with those plastic anchors,
because shooting in the nails might explode the cement. I'd be totally
grateful to anyone sharing their experience with this.

Marianne

--
Marianne Halevi

If you have a ROTARY HAMMER drill, not a hammer drill, then Tapcon
screws will work very well. Not the plastic anchor things you
mention. Tapcon screws bite into the concrete itself and hold well
enough for anything that is not subject to extreme forces. You don't
have to use lots and lots of Tapcon screws to hold the plywood down
since gravity will help considerably. Use the correct undersized
drill bit. Something like 5/32" drill for 3/16" screws I think.
Hammer drills are so slow and stop when hitting aggregate I cannot
stand to use them with Tapcon screws. I hate hammer drills. For
attaching electrical boxes to concrete walls, use the Tapcons with a
rotary hammer drill.

The powder actuated nails work very well and are very quick. Every
now and then you get blowout of the concrete. But not too often
really. You minimize this occassional problem considerably by firmly
pressing down on the wood being fastened to the concrete. For
attaching framing to floors and walls in basements, this is the method
to use. And any blowout is going to be underneath and hidden so you
will never see it or even know.

Marianne Halevi wrote:
So I'm back with a question about my T&G wood floor in the converted
garage. I was going to put 3/4 inch plywood down on the cement floor
first, on top of a vapor barrier. How do I make sure the plywood stays
down? One person says shoot 22-caliber nails, 6 or 8 per 4x8 sheet of
plywood (he would lend me the gun), another says drill through the
plywood into the cement and put in screws with those plastic anchors,
because shooting in the nails might explode the cement. I'd be totally
grateful to anyone sharing their experience with this.

I'll play the devil's advocate for a moment.

Yes, you could shoot Hilti nails, yes you could drill for concrete
anchors, but WHY?

Assuming this is a typical garage of about 10 x 20, accurately fitting
and installing plywood cut from 4 x 8 sheets is NBD.

(BTW, a typical sht of 3/4 ply weighs in around 60-65 lbs)

A layer of 3/4 T&G on top of the plywood will insure minimum movement
of the plywood sheets relative to one another.

It will also add another 50-60 lbs/4x8 section.

On top of this construction, equipment, benches, etc, will be placed.

Assuming the floor is kept dry, nothing is going to move or warp.

BTW, I'd use adhesive rather than nails to install the T&G.

Lew

Some interesting ideas already expressed....
I'd be thinking of something a little different...
I think framing the concrete floor with 2x4's first then plywood then tongue
and groove.
I would tend to leave the 2x4's floating to allow for seasonal changes. I
don't know where you live but here in southern Illinois it will be hot as
blazes with high humidity one day and cold as snot the next.
Also by floating your 2x4's you get a chance to level up the floor so your
tongue and groove will install nicely and not be as subject to peaks and
valleys casued by uneven concrete.

entrance into the garage could be an interesting challenge but I'm sure
could be overcome very gracefully....maybe even allow for a small ramp to
roll your heavy equipment.

Just some thoughts.

good Luck.
Thom

"Lew Hodgett" wrote in message
nk.net...
Marianne Halevi wrote:
So I'm back with a question about my T&G wood floor in the converted
garage. I was going to put 3/4 inch plywood down on the cement floor
first, on top of a vapor barrier. How do I make sure the plywood stays
down? One person says shoot 22-caliber nails, 6 or 8 per 4x8 sheet of
plywood (he would lend me the gun), another says drill through the
plywood into the cement and put in screws with those plastic anchors,
because shooting in the nails might explode the cement. I'd be totally
grateful to anyone sharing their experience with this.

I'll play the devil's advocate for a moment.

Yes, you could shoot Hilti nails, yes you could drill for concrete
anchors, but WHY?

Assuming this is a typical garage of about 10 x 20, accurately fitting
and installing plywood cut from 4 x 8 sheets is NBD.

(BTW, a typical sht of 3/4 ply weighs in around 60-65 lbs)

A layer of 3/4 T&G on top of the plywood will insure minimum movement
of the plywood sheets relative to one another.

It will also add another 50-60 lbs/4x8 section.

On top of this construction, equipment, benches, etc, will be placed.

Assuming the floor is kept dry, nothing is going to move or warp.

BTW, I'd use adhesive rather than nails to install the T&G.

Lew

On May 11, 10:24 am, Marianne Halevi Marianne.Halevi.
wrote:
So I'm back with a question about my T&G wood floor in the converted
garage. I was going to put 3/4 inch plywood down on the cement floor
first, on top of a vapor barrier. How do I make sure the plywood stays
down? One person says shoot 22-caliber nails, 6 or 8 per 4x8 sheet of
plywood (he would lend me the gun), another says drill through the
plywood into the cement and put in screws with those plastic anchors,
because shooting in the nails might explode the cement. I'd be totally
grateful to anyone sharing their experience with this.

Your concrete slab is not flat. It looks flat, but it's not. Very
possibly it also has a slight pitch towards the doors, or if there is
a floor drain in the middle of the garage, the pitch will be towards
the drain. The little 1/8" (or less) pitch per foot can wreak havoc
when you're trying to put in a flat, level and stable floor.

Six or eight fasteners per sheet of plywood will keep it from sliding
around and will keep the corners pinned down, but it will do nothing
to keep the plywood from warping. The plywood's bottom side will be
sitting on a vapor barrier in your scenario and the top side will be
under the T&G - these are two very different conditions and the
plywood will curl away from whichever side is the wettest or
experiencing the highest humidity. Not a good situation.

A better solution would be to use a sleeper system - wood fastened or
glued to the slab with construction adhesive. The sleepers should be
shimmed level. If you use 2x sleepers they should be shimmed every
foot or so. A plastic vapor barrier is draped over the sleepers and
rigid insulation is then installed between the sleepers (you didn't
say where you are located - if you're in the South you can omit the
insulation). The plywood subfloor is screwed to the sleepers,
building felt laid on top of the subfloor, then the T&G is installed.

As an alternative, you could use one of those easy to handle panelized
subflor systems, such as Subflor. There is no need to add an
additional vapor barrier or attach the panels to the slab as they're
designed to be a floating floor system.
http://www.subflor.com/ADVANCE/home.asp A big box store should carry
them.

R

Marianne Halevi wrote:
So I'm back with a question about my T&G wood floor in the converted
garage. I was going to put 3/4 inch plywood down on the cement floor
first, on top of a vapor barrier. How do I make sure the plywood
stays down? One person says shoot 22-caliber nails, 6 or 8 per 4x8
sheet of plywood (he would lend me the gun), another says drill
through the plywood into the cement and put in screws with those
plastic anchors, because shooting in the nails might explode the
cement. I'd be totally grateful to anyone sharing their experience
with this.

Exploding concrete isn't the problem with the powder ones. True, a
smallish area may chip off at the point of impact but that doesn't
effect the holding power.

The problem is that they come in different loads and you have to know
the concrete density to select the proper load...too weak and they
won't go in all the way and you'll have to hammer in manually; too
strong and they may well go clean through the plywood. Even if you
know the concrete density you'll probably find areas that are harder
or softer. And 6-8 nails is not nearly enough.

Screws into plastic anchors are a lousy solution. The anchors, not
the screws. Lead anchors are much better. Or tapcons as others
suggested. And more than 6-8.

--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

On Fri, 11 May 2007 21:46:21 GMT, "dadiOH"
wrote:

Exploding concrete isn't the problem with the powder ones. True, a
smallish area may chip off at the point of impact but that doesn't
effect the holding power.

The problem is that they come in different loads and you have to know
the concrete density to select the proper load...too weak and they
won't go in all the way and you'll have to hammer in manually; too
strong and they may well go clean through the plywood. Even if you
know the concrete density you'll probably find areas that are harder
or softer.

I've used lots of Hilti (and generic copy) 22 ca. nails, and find that
testing easily determines the proper force load. A few may still
screw up, but you'll be in the ballpark.

The real issue I've seen is concrete that's too fresh and concrete
with too much aggregate. The fresh stuff falls apart, and the
aggregate is rocks! G

Wow, what a bunch of good and useful information! I thank you all so much. - Floor not level? O-oh! I never thought about that. - Insulation? I was kind of trusting that I wouldn’t need that, since I live in Southern Cal. - Sleepers with shims? Sounds very good, but I think the level of the floor would then turn out higher than the thresholds (I already have two doors installed with red brick steps outside). It seems that those Tapcon screws you talk about is what I will use for the plywood (I’ll remeber the rotary hammer!) Maybe I can use shims to make the plywood subfloor as level as possible? Maybe use glue as well to keep it down? Building felt under the T&G also sounds good, and I’ll look into that too. But why use adhesive rather than nails?

Marianne

Marianne Halevi wrote:

Wow, what a bunch of good and useful information!

The man has been to the movie.

I thank you all so
much. - Floor not level? O-oh! I never thought about that. -
Insulation? I was kind of trusting that I wouldn’t need that, since I
live in Southern Cal.

SoCal or not, insulation is a good thing to minimize sweating problems.

BTW, what part of SoCal?

- Sleepers with shims? Sounds very good, but I
think the level of the floor would then turn out higher than the
thresholds (I already have two doors installed with red brick steps
outside).

It probably will, but you work around it.

But why use adhesive rather than
nails?

Nails are metal, metal rusts, especially in a converted garage.


Lew

Aha! Rust! I guess that would go together with the sweating. The only thing is, I am kind of paranoid about fumes. All this chemical stuff that exudes potentially toxic vapors, but I think it's worthwhile to check out where different adhesives fall in that respect.

Otherwise: Tapcon screws it will be (with lead anchors!), because definitely my concrete is of a rather low quality - I have already seen it disintegrating in some places and had to patch it.

Gosh, I've learned such a lot. Thanks again to all! - It's L.A. area, BTW, San Fernando Valley.


Marianne

Marianne Halevi wrote:

Otherwise: Tapcon screws it will be (with lead anchors!),

Tapcons don't need/use anchors of any sort...all that is needed is a
hole of the correct diameter and depth.


--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

Marianne Halevi wrote:

Aha! Rust! I guess that would go together with the sweating. The only
thing is, I am kind of paranoid about fumes. All this chemical stuff
that exudes potentially toxic vapors, but I think it's worthwhile to
check out where different adhesives fall in that respect.

Don't sweat it.

SCAQMD has so many restrictions concerning products with VOC's that
you will be lucky to find a good adhesive to do the job.


Otherwise: Tapcon screws it will be (with lead anchors!), because
definitely my concrete is of a rather low quality - I have already seen
it disintegrating in some places and had to patch it.

Just curious, have you ever had any flooding problems with this garage
space?

Didn't happen this year, but 2"-3" of rain in 24 hours can have some
interesting results.

It's L.A. area,
BTW, San Fernando Valley.

Unlike the beach, you definitely can get some large variations in
temperature in the valley. Plan on addressing insulation issues to
minimize possible sweating problems.

Lew

On May 12, 11:08 am, Marianne Halevi Marianne.Halevi.
wrote:
Lew Hodgett Wrote:



Marianne Halevi wrote:
-
Wow, what a bunch of good and useful information!-

The man has been to the movie.
-
I thank you all so
much. - Floor not level? O-oh! I never thought about that. -
Insulation? I was kind of trusting that I wouldn't need that, since I
live in Southern Cal. -

SoCal or not, insulation is a good thing to minimize sweating
problems.

BTW, what part of SoCal?

- Sleepers with shims? Sounds very good, but I-
think the level of the floor would then turn out higher than the
thresholds (I already have two doors installed with red brick steps
outside). -

It probably will, but you work around it.
-
But why use adhesive rather than
nails?-

Nails are metal, metal rusts, especially in a converted garage.

Lew

Aha! Rust! I guess that would go together with the sweating. The only
thing is, I am kind of paranoid about fumes. All this chemical stuff
that exudes potentially toxic vapors, but I think it's worthwhile to
check out where different adhesives fall in that respect.

I'd worry a LOT more about having to redo the whole job from the
ground up
because of adhesive failure than fumes in the garage for 24 hours,
assuming
you can actually buy solvent-based glues anywhere in CA. I've had
Liquid
Nails water-based subfloor glue fail between concrete and pressure-
treated
plates (you'll want CDX ply, essentially pressure-treated subfloor
plywood,
in that garage) and I'll neither use nor recommend it.

As for solvents, they're tested on white mice of a certain strain
in an effort to see how much is needed to make half of them sick
or die. Unless you're a mouse of a susceptible strain, don't worry.
Limit your exposure and crack the windows until the fumes are gone.
Or pay someone else to lay the subfloor.

Otherwise: Tapcon screws it will be (with lead anchors!), because
definitely my concrete is of a rather low quality - I have already seen
it disintegrating in some places and had to patch it.

These, I love and do recommend. Big, coarse, cement-eating threads.
No anchors needed.

Gosh, I've learned such a lot. Thanks again to all! - It's L.A. area,
BTW, San Fernando Valley.

What are your seismic codes? Would a floating subfloor be preferable?

Father Haskell wrote:

I'd worry a LOT more about having to redo the whole job from the
ground up
because of adhesive failure than fumes in the garage for 24 hours,
assuming
you can actually buy solvent-based glues anywhere in CA. I've had
Liquid
Nails water-based subfloor glue fail between concrete and pressure-
treated
plates (you'll want CDX ply, essentially pressure-treated subfloor
plywood,
in that garage) and I'll neither use nor recommend it.

Liquid Nails would definitely NOT be my adhesive of choice.

Much prefer SikaFlex or even 3M, 5200.

SikaFlex is a major player in both the marine and
industrial/construction adhesive markets.

Lots of industrial distributors.

Tech service has an 800#, are in Detroit, and a savvy bunch.

Lew

On Sat, 12 May 2007 16:08:31 +0100, Marianne Halevi
wrote:

Otherwise: Tapcon screws it will be (with lead anchors!), because
definitely my concrete is of a rather low quality - I have already seen
it disintegrating in some places and had to patch it.

As someone pointed out, Tapcons don't require lead anchors or anything
in the hole.
If your wood floor will be directly over the plywood, the thing you
may need to watch for is that the heads of the Tapcon screws end up
flush with the top of the plywood. We install the Tapcons with a hex
socket loaded in a drill but using this method getting the head sunk
into the plywood can be a problem. You may want to counter sink the
hole before installing the screw.

Mike O.

Hold it ! - I am starting to be a little bit confused, almost starting to see white mice running around in circles, not fume-induced either.
Maybe this is what I think I should do after absorbing all you smart people’s advice: First on the cement goes tar-paper against moisture, then the plywood with the Tapcon screws (3/16 - coarse, cement-eating threads - with a 5/32 drill bit - rotary hammer drill), no anchors. No adhesive failure either. Drilling the hole a little deeper than the screw (I remember that part). Then a layer of building felt for a little give (I like that idea). Then, how can I use glue for the T&G on top of that? I can’t. So I use the nails, sweat or not. The garage has never flooded in the past 10 years that I have lived here. Earthquake? Well, everything is still standing, so maybe I am o.k. (I am not in Northridge). So, do you think that is good procedure? Any concerns or objections or better ideas?
As always, grateful, Marianne.

Ah yes, and countersinking too!

Marianne Halevi wrote:

Maybe this is what I think I should do after absorbing all you smart
people's advice: First on the cement goes tar-paper against
moisture, then the plywood with the Tapcon screws (3/16 - coarse,
cement-eating threads - with a 5/32 drill bit - rotary hammer
drill), no anchors. No adhesive failure either. Drilling the hole a
little deeper than the screw (I remember that part). Then a layer
of building felt for a little give (I like that idea). Then, how
can I use glue for the T&G on top of that? I can't. So I use the
nails, sweat or not. The garage has never flooded in the past 10
years that I have lived here. Earthquake? Well, everything is still
standing, so maybe I am o.k. (I am not in Northridge). So, do you
think that is good procedure?

Yeah.
___________

Any concerns or objections or better ideas?

1. Get ply made for the purpose...it has T & G edges

2. Stagger the ply joints.



--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

Great, I'm all set now, feel very confident about the project. Thanks again a million.

Marianne

(Hail to early risers!)