"Chub" wrote in message
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"chris jung" wrote in message
...

"Ken" wrote in message
...
How thick should plywood decking be assuming you are using joists 16" on
center?

In my earlier years, perhaps 20 years ago, I worked for a builder who
typically used 5/8 floor decking and 1/2" on the roof and exterior
walls. Now I'm faced with an architect that insists 3/4" on the floors
is a must and 5/8" on the roof and walls is needed.

Does the floor decking depend on the finish flooring. The builder I
worked with would always install wide plank 3/4" hardwood flooring.
But when I mentioned that to the architect, he insisted that I should
still use 3/4" decking under it. His concern was regarding the holding
capacity of the nails for the hardwood flooring and that it would avoid
squeaky floors later.


Our house (a raised ranch) was built in 1967. The floor joists are 16"
apart, the subfloor is 1/2" plywood with 3/4 tongue & groove oak over
that. The floor is squeaky everywhere and you can actually see it flex.
In March, we are having the main hallway and a smaller hallway/foyer
floor ripped up and new 3/4" subfloor and new 3/4 oak put in. It's a pity
since the original oak flooring is very handsome. We can't afford to redo
the subfloor & flooring on the entire house at this time.

If the builder had done it right the first time (put in 3/4" subfloor) we
wouldn't have to through all this expense and hassle now. So my advice
is to go with the 3/4" - you want that subfloor as stiff as possible.

Chris

why not just put new flooring on top and not go through ripping out old
stuff?

For a few reasons. First some background. We have a apartment in our lower
level. One bedroom is under the hallway and there is a metal furnace duct
running the length of the hallway between the joists and ceiling. Sound
(both airborne and through vibration) travels and is even amplified by that
duct. To stop this it's recommended to wrap the duct in Mass Loaded Vinyl
( go to http://www.soundproofing.org/ for more info). To get to the duct we
would have to either go from below (through 2 layers of drywall) or above.
We decided to get to it from above.

If we were having all the wood floor redone (1250 sq foot) then we would
consider having the old subfloor & oak floor screwed together to make a new
subfloor and then put a new floor on top. To put a new floor on the entire
1250 sf would cost a big chunk of change. And as well, the kitchen and 2
bathrooms are tile (at least they were done right) and we would end up with
them being at 3/4" lower than the wood floor. With our plan, the difference
in floor height between the tile and wood floor will be 1/4 inch.

And lastly our house is a split entry with two half flight of stairs leading
up to the wood floor. From what I understand, it's important that stair
risers are the same height otherwise people will catch their toes on the
highest step. I'm not sure if a 3/4" taller top step is a true safety issue
but it was one last factor that influenced our decision.

Chris