On Sep 10, 7:51 am, wrote:
Hi

I am in the process of building a storage platform under my deck.
My deck is 12' depth (attached to foundation wall on one side) and 14'
feet wide.
The deck is about 5' above the ground level.
The storage platform will be 8' deep (leaving about 4 ' to the
foundation wall) and 14' wide.

A rudimentary drawing looks like

___Foundation Wall____________
| | 4'
|____________________________|
| |
12' | Storage |
| Platform | 8'
| |
|____________________________|
14'

To build the storage platform:

A. Put 4x4 pressure treated lumber (rated for ground contact/use - ACQ
0.40 pcf) running perpendicular to the foundation wall to act as beams
for the platform. Each of these 4x4 will be 8' long and with a
distance of 2' from one beam to the next,

___Foundation Wall____________
| | 4'
|____________________________|
| | | |
| | 4x4 | |
| | | .... | 8'
| 2' | 2' | |
|____ |_____|_________________ |
14'
Lawn side P

B. Install pressure treated lumber decking boards (5/4" x 6" x 14')
across top of the 4x4 beams, so that each decking board will sit on
all the 4x4 beams across the width of the platform.

C. Make the storage platform area "water proof" by installing
corrugated PVC panels below the deck. These panels will be installed
at a slant, with the highest point of each panel being near to the
foundation wall and be 2" lower on the other end (Lawn side P in
diagram above). This will cause any water that falls from above the
deck to run out through the channels in the corrugated PVC out onto
the lawn. I can even install a rain gutter at the end to cleanly
channel this water out.

D. Use privacy lattice on 3 sides. Install a door made of pressure
treated lumber on one side.

My questions are to do what can be done to make this area bug/insect/
animal proof? Thoughts I have had are following:

1. Install thick landscape fabric or 0.6 mil plastic sheet on the
ground below the 4x4 lumber beams. Will these help to prevent bugs
coming up the ground into the storage area? Given the PVC roof above
the platform that will prevent the water from falling onto the storage
platform area, will there be advantages to using the landscape fabric
v/s the plastic sheet? Are there any advantages or disadvantages of
the fabric or the plastic sheet?

2. Will attaching window screening to the privacy lattice and door to
prevent bugs and insects from coming outside into the storage area.

3. Any other advice on whether the above plan will work or not? Any
modifications that will help address any problems you see?

Thanks
bob

Sounds like you have a pretty goodi plan for your storage area.

I think making it completely bug proof is going to be difficult. The
screening on the inside of the lattice will be a good thing. Bugs are
looking for moisture , food & protected area to lay eggs. As much
as you allow or prevent these conditions or deny access will determine
your success.

One thing I didn't understand, how are the ends of the 4x4's
supported?

Also 4x4's are not the best choice for beams, I would suggest 2x6's or
2x8's depending on how much weight you're planning on storing.

cheers
Bob

The plastic on the soil will get the area drier by preventing
moisture from coming up out of the ground.