"Dick Shenary" wrote in message
...
Does roofing felt serve an additional function when laid under a
hardwood floor besides being a moisture barrier?
I'm installing 3/4" plank in an upstairs room over a plywood
sub-floor.
Do I need felt underneath?

I think it is also used to control squeaks. That said I would use 30# felt
and not the cheaper 15#.


Colbyt

See the NOFMA web site for installation tips.
NOFMA is a wood flooring manufactureres association.
They should know what they are talking about.
TB

wrote:
See the NOFMA web site for installation tips.
NOFMA is a wood flooring manufactureres association.
They should know what they are talking about.
TB

I don't get it. What is with the 'do I need felt' questions this year.
The cost of the felt is such a miniscule amount compared to the other
material why the hell not use it when it is recommended?

Harry K

Dick Shenary wrote:
Does roofing felt serve an additional function when laid under a
hardwood floor besides being a moisture barrier?
I'm installing 3/4" plank in an upstairs room over a plywood
sub-floor.
Do I need felt underneath?

Let me start by saying that I personally use felt on every job. It
takes only a few minutes to put down, costs a few bucks and you have a
nice clean floor to work off of.

When I pull up old strip floors there's always paper between the finish
flooring and the diagonally-sheathed 1xwhatever subfloor. The paper,
any paper, acts as a barrier in such floors. It keeps dust and dirt
from percolating down through the subfloor. Usually the paper I find
is red rosin paper and not building felt. Possibly the use of felt is
just a holdover from the old 1x subfloor days.

I don't think felt's moisture barrier qualities are its main function
in a floor that's over conditioned space. Over a crawl space it's
cheap insurance.

The subfloor and strip flooring do expand and contract at different
rates, so there is slidng of one on the other. Having paper
facilitates that sliding, but to what degree I can't tell you - never
seen a study on it.

R