Installing Sheathing Under Bays - Quick Tip

[sparkplug188]

If you are considering installing aluminum or plastic sheathing under the bays, consider making one of these--

I had to drill 80 pilot holes for self tapping screws.  This rig saved me at least 6 hours of awkward angle drilling and pulled muscles.

[Hobie]

Love it!!!  Great idea.

[Resistol30]

How thick is the plastic sheeting?

[sparkplug188]

The sheets are 0.157" thick.  One side is white and the other is black.  This is the same material Fleetwood uses to protect the slide out mechanisms on their travel trailers.

48 in. x 96 in. White Corrugated Plastic Cardboard - 10 PACK
Home Depot internet item number: 202489118
Model number: WC4896-10
Online special order only. $110 for a 10 pack as of 5/30/2014

[eagle19952]

ok. I am a little slow tonight....how does your apparatus make drilling holes easier ??

[sparkplug188]

It is a drill press turned upside down and mounted to a bucket.  I lightly pull the lever and the drill bit is pushed up into the frame rails of the bus.  The alternative is manually pushing a drill up into the frame rails with an awkward twisting motion of your upper torso. Imagine lying on your side and trying to hold a 20lb weight a couple inches off the floor for 6 hours.  I will take a 5lb straight lever pull any day over that.  

Edit: In the picture, the lever turns counter clockwise.  That may have been the source of some confusion.

[Brian Diehl]

Hi Sparkplug,
I like your drill jig.  That is using your head!

On the sheeting it doesn't look like you overlapped your seams.  You may want to consider putting some bracing along the seams to keep them closed.  Otherwise they will gap over time and allow that dreaded water into your nice beautiful steel.  Just a thought.

[Lee Bradley]

Good tip and good looking job. 

One question; are those press board sheets staying? I used marine grade plywood, primed and finished with bilge paint, anywhere there could be damp and/or oil.

[eagle19952]

oh....In my confusion, I did not scroll right...now I see, as I picked up my hammer and saw....

[sparkplug188]

It only looks like the seams aren't overlapped.  The plastic sheathing is very similar to cardboard-- one wavy sheet of plastic, called a flute, sandwiched between two flat sheets called liners.  I cut the flute back about an inch from the end of the sheathing where two pieces meet, then overlapped the liners inside of each other.

Lee-  I highly recommend checking out the AdvanTech Flooring Youtube Page.  AdvanTech is an ultra high density oriented strand board that vastly outperforms standard pine plywood.  It is not quite as good as marine grade plywood, but certainly comes close and at a fraction of the cost.  Priming and painting all six sides of every board with a high quality paint, like bilge paint, makes a much bigger difference than the type of substrate used.  Several coats of high quality paint will block moisture and keep almost any substrate from rotting.

[eagle19952]

From another web site for your consideration:

We tried painting some Advantec and it did not work out so good. We used oil based paint but it bubbled in places. We tested another area with spray paint, just plain white spray paint and it did stick but did not look so good. We stopped and called the company and they said it was not made to paint.

Weighs a ton - sheeted a house with 1 1/8" Advantec a few years ago and it took two guys to carry a sheet.

I have been nailing subfloor down, everything from high dollar fir T&G plywood to commodity grade OSB, for three decades now, it's always been that way. Advantech BTW, is as good as it gets.

[sparkplug188]

Eagle- Everything you posted is absolutely true.  I tried several oil based paints on some AdvanTech scraps and had the same problem with bubbeling and poor adhesion.  I did some research and found this on the Huber website:

AdvanTech panels can be left natural, stained, varnished or painted with oil or epoxy based paints or oil based primer and latex paint. Water seal is not recommended. AdvanTech panels are not recommended for exterior siding or other applications that are permanently exposed to the weather.

I have had good results using Marine Clean degreaser to clean the panels, followed by Killz oil based primer, lastly Valspar high gloss exterior latex paint.  It would be a real bumber to paint a dozen sheets of Advantech only to watch it slowly bubble up as it dries, then discover this post.  Test samples are critical.

It weighs a ton-- yes, it does! It has a much higher density than plywood which makes it heavier and more rigid than plywood.  It will certainly add a few hundred pounds to a conversion, compared to plywood.

Any place where I would consider using soft pine plywood, AdvanTech has taken its place.