"Phisherman" wrote in message
...
On Mon, 28 Jul 2008 19:59:55 -0700 (PDT), Joe wrote:

On Jul 27, 2:37 pm, "Bob F" wrote:
When I repaired a deck, I decided to put a strip of 15lb tar paper over the
joists before attaching the deck boards. The tar paper was about 1/2" past
the
edge of the joist, and then lightly folded down to form a drip edge. My
theory
is that the tar paper will tend to run rainwater away from the joists, and
drip
it slightly away from them, extending their life. Any opinions out there?

Rather than roofing felt, try to find some of the newer plastic
roofing underlayments, like PermaFelt. Much thinner, tougher, longer
lasting than tarpaper. Most roofing supply companies have it, some box
stores. Problem is getting a small quantity as roll sells for $90. Try
scrounging a dozen feet or so from a roofing company from left over
rolls. HTH

Joe


I've never heard about using tar paper over deck joists. Wouldn't
that create a situation if the wet wood underneath could not dry out?
My deck is 17 years old and still holding strong without any rot and
no tar paper, but I ally Cabot Decking stain every 3-4 years.

The rest of the joist is still exposed. The only area not available for
evaporation is the top edge. Joist rot may be less of a problem in dryer
climates than here in Seattle.