Building ground level deck... Concerns: short lifetime expected due to lack
of space for proper air circulation under deck, plus high moisture levels
from both sky and ground (i.e. rainy Vancouver weather and high water-table
clay soil, respectively). I've put much thought and research into how to
best counter this... Now I've finally arrived at my final choices of
strategy/design/materials, as follows: Ipe for the decking material, drain
rock down to a depth of 9" to 12" below grade (in conjunction with
pre-existing landscape drainage), thorough sealing of PT frame joists and
beams with double wet coat oil based paint/sealer.

Now, here's my question: How can I _keep_ the frame (i.e. joists) sealed
against moisture in spite of the fact that the screws (for fastening the
decking) will be piercing whatever sealer/paint I've put there?

I've read that dipping the deck screws in hot paraffin wax prior to use will
cause the screws to form a water-tight seal (as well as, primarily of
course, facilitate the screw's entry into the wood). But I'm having
difficulty visualizing how this would actually be accomplished ... Unless
there is maybe some kind of simple and portable hot-wax-applicator-gun or
similar device available that I am just not aware of (...?).

Ken

"Ken Moiarty" wrote in message
news:dZq%e.27498$tl2.8863@pd7tw3no...
Building ground level deck... Concerns: short lifetime expected due to
lack of space for proper air circulation under deck, plus high moisture
levels from both sky and ground (i.e. rainy Vancouver weather and high
water-table clay soil, respectively). I've put much thought and research
into how to best counter this... Now I've finally arrived at my final
choices of strategy/design/materials, as follows: Ipe for the decking
material, drain rock down to a depth of 9" to 12" below grade (in
conjunction with pre-existing landscape drainage), thorough sealing of PT
frame joists and beams with double wet coat oil based paint/sealer.

Now, here's my question: How can I _keep_ the frame (i.e. joists) sealed
against moisture in spite of the fact that the screws (for fastening the
decking) will be piercing whatever sealer/paint I've put there?

I've read that dipping the deck screws in hot paraffin wax prior to use
will cause the screws to form a water-tight seal (as well as, primarily of
course, facilitate the screw's entry into the wood). But I'm having
difficulty visualizing how this would actually be accomplished ... Unless
there is maybe some kind of simple and portable hot-wax-applicator-gun or
similar device available that I am just not aware of (...?).

Ken

This is a question for me as much as it is for you. Why use any sealer at
all on the PT joists/frame?
I built a deck with PT and EON (plastic) deck boards. I did seal end cuts
with wood preservative but I thought PT would not need anything else even
with direct ground contact?
Kevin

The question of sealing a wood member, then poiking holes in the
sealing coat is worth consideration. Moisture might be let in through
the punctures, then held in the wood by the sealing coat.

An Example: Government facility was designed with cypress hand rail
around large court yard. After installation, handrail was painted
except for counter sunk bolts. Three months (as I remember it) later,
fungus was growing out of the hand rail. Steel tube was substituted.
TB

"Ken Moiarty" wrote in message
news:dZq%e.27498$tl2.8863@pd7tw3no...
Ipe for the decking material,

Use Penofin Oil to protect it.


thorough sealing of PT frame joists and beams with double wet coat oil
based paint/sealer.

Some sealers won't do anyting on PT wood because there is so much surface
oil on it anyway. I'm not usre it will help at all.


Now, here's my question: How can I _keep_ the frame (i.e. joists) sealed
against moisture in spite of the fact that the screws (for fastening the
decking) will be piercing whatever sealer/paint I've put there?

It won't. But PT will is saturated through and it whould not be needed.


I've read that dipping the deck screws in hot paraffin wax prior to use
will cause the screws to form a water-tight seal (as well as, primarily of
course, facilitate the screw's entry into the wood).

I don't know about that. You may want to go to www.mcfeelys.com as they
have a lot of information on deck screws and materials.

IMO, you can eliminate most of this by putting in a concrete patio instead.
Less maintenance and will last 200 years.

We use "re-kiln dried" treated lumber because the "wet" stuff tends to
warp & twist.
The kiln dried is more expensive and yields more usable pieces.
TB

How low is your deck to the ground?

We just replaced our previous deck. The old deck was relatively
structurally sound -- very little, if any, rot. (the wall behind the ledger
board, left unflashed, was another story). The builder didn't seem to take
any precautions at all other than using PT lumber, and the deck seemed fine
after 25 years (we wanted a larger deck with a stairway).

Ours is about 7' off the ground to the deck surface, so that might make a
difference. But I've never heard of anyone doing anything like dipping
screws in wax or anything like that...

-Tim

On 10/1/2005 3:33 AM US(ET), Ken Moiarty took fingers to keyboard, and
typed the following:

Building ground level deck... Concerns: short lifetime expected due to lack
of space for proper air circulation under deck, plus high moisture levels
from both sky and ground (i.e. rainy Vancouver weather and high water-table
clay soil, respectively). I've put much thought and research into how to
best counter this... Now I've finally arrived at my final choices of
strategy/design/materials, as follows: Ipe for the decking material, drain
rock down to a depth of 9" to 12" below grade (in conjunction with
pre-existing landscape drainage), thorough sealing of PT frame joists and
beams with double wet coat oil based paint/sealer.

Now, here's my question: How can I _keep_ the frame (i.e. joists) sealed
against moisture in spite of the fact that the screws (for fastening the
decking) will be piercing whatever sealer/paint I've put there?

I've read that dipping the deck screws in hot paraffin wax prior to use will
cause the screws to form a water-tight seal (as well as, primarily of
course, facilitate the screw's entry into the wood). But I'm having
difficulty visualizing how this would actually be accomplished ... Unless
there is maybe some kind of simple and portable hot-wax-applicator-gun or
similar device available that I am just not aware of (...?).

Ken


I built a 19' wide x 16' deep deck with the joist bottoms about 2" from
the dirt on one end and about 8" on the other end. The ground beneath
sloped slightly to the one end. I did not seal the PT joists but put a
black plastic moisture barrier on the dirt underneath with holes punched
into the plastic in the low spots (for water drainage for those parts
where the water could not run out from beneath the deck. I used rocks to
hold the plastic down.
The deck was up for about 17 years before it was torn down to be
replaced with a sunroom. The joists were in such good condition that I
was able to save and use them for other projects, including a small deck
on the side of the sunroom. A few, that were going to be exposed on the
new projects, needed a little sanding to remove dirt and deck staining
that had dripped between the decking. After sanding, they looked like
new wood.
This was the old PT formula, so I don't know how well the new stuff
holds up.

--
Bill

On 10/1/2005 3:33 AM US(ET), Ken Moiarty took fingers to keyboard, and
typed the following:

Building ground level deck... Concerns: short lifetime expected due to lack
of space for proper air circulation under deck, plus high moisture levels
from both sky and ground (i.e. rainy Vancouver weather and high water-table
clay soil, respectively). I've put much thought and research into how to
best counter this... Now I've finally arrived at my final choices of
strategy/design/materials, as follows: Ipe for the decking material, drain
rock down to a depth of 9" to 12" below grade (in conjunction with
pre-existing landscape drainage), thorough sealing of PT frame joists and
beams with double wet coat oil based paint/sealer.

Now, here's my question: How can I _keep_ the frame (i.e. joists) sealed
against moisture in spite of the fact that the screws (for fastening the
decking) will be piercing whatever sealer/paint I've put there?

I've read that dipping the deck screws in hot paraffin wax prior to use will
cause the screws to form a water-tight seal (as well as, primarily of
course, facilitate the screw's entry into the wood). But I'm having
difficulty visualizing how this would actually be accomplished ... Unless
there is maybe some kind of simple and portable hot-wax-applicator-gun or
similar device available that I am just not aware of (...?).

Ken


I built a 19' wide x 16' deep deck with the joist bottoms about 2" from
the dirt on one end and about 8" on the other end. The ground beneath
sloped slightly to the one end. I did not seal the PT joists but put a
black plastic moisture barrier on the dirt underneath with small holes
punched into the plastic in the low spots (for water drainage for those
parts where the water could not run out from beneath the deck). I used
rocks to hold the plastic down.
The deck was up for about 17 years before it was torn down to be
replaced with a sunroom. The joists were in such good condition that I
was able to save and use them for other projects, including a small deck
on the side of the sunroom. A few, that were going to be exposed on the
new projects, needed a little sanding to remove dirt and deck staining
that had dripped between the decking. After sanding, they looked like
new wood.
This was the old PT formula, so I don't know how well the new stuff
holds up.

--
Bill

"Kevin Ricks" wrote in message
...

[...]
This is a question for me as much as it is for you. Why use any sealer at
all on the PT joists/frame?
I built a deck with PT and EON (plastic) deck boards. I did seal end cuts
with wood preservative but I thought PT would not need anything else even
with direct ground contact?
Kevin


Two more considerations: (1) The fact that my deck is going to be hemmed in
almost completely around its circumference by pre-existing landscape
planters. (A certain lady of the house, and master lanscape architect for
the yard, is responsible for this arrangement; not my choice...) This means
that (unless I were to install industrial duty fans underneath - not
likely), air circulation underneath the deck will be 'unacceptably' poor.
(2) With the recent change in PT wood specifications from arsenate based
preservative to less toxic alternative(s), I won't be surprised when/if in a
few short years it gradually becomes apparent to consumers that "PT lumber
don't last as long as it used to". I don't *foreknow* this will be the
case, of course. But I see no basis to place much faith in lumber makers'
and/or the governments' present assurances to the contrary. For one thing,
they just don't have 30 or so years experience with the newer stuff having
been used _in the field_ to be able to properly compare it to the
conventional product, in my opinion. And afterall, the lumber makers just
want us to buy the stuff, and our governments, well, they have their own
bottom line too. So they each tell the public, "all the public *needs* to
know" (for the time being, that is). In summary, I'm trying hard to err on
the side of caution here.

Ken

Thanks. I wasn't aware of this. I'll be sure to get the kiln dried PT
lumber.

Ken
wrote in message
oups.com...
We use "re-kiln dried" treated lumber because the "wet" stuff tends to
warp & twist.
The kiln dried is more expensive and yields more usable pieces.
TB

"Tim Fischer" wrote in message
...
How low is your deck to the ground?

The bottom of the joists about 6 inches off the ground.

[...] But I've never heard of anyone doing anything like dipping screws in
wax or anything like that...


I got this tip from
http://www.woodsthebest.com/ipe_deck..._fastening.htm

"Dipping the screws in paraffin wax, prior to installation, will allow for
easier insertion, and the wax will seal the hole."

There are many references that describe using wax to lubricate wood screws.
But this is the only reference I know of that describes this use of wax on
screws as also serving to "seal the hole" . I was hoping other people here
had heard about or knew something more about this and could therefore
comment.

Ken

"Christian Fox" wrote in message
...
[...]
What you need to make sure you use, however, is fasteners that are
DESIGNED to work with
the type of PT lumber you're using. The chemicals in ACQ PT lumber (the
most common
kind) will corrode most types of fasteners - use hot-dipped galvanized
screws or
stainless steel.

I'm leaning towards screws made of stainless steel. I had previously
thought I'd use polmer coated screws. I got this idea after reading thru
the web site of a deck building outfit that claims to use only the best
materials, including "poly-coated screws". (See
http://www.deckspecialists.com/) But I've found no other references to
support this idea, and using stainless steel screws appeals to me
intuitively (provided the stainless steel used is of the of proper type and
quality, etc... see http://www.key-to-steel.com/Articles.asp).

Ken