Plywood floor question

[roadinspector]

To keep from highjacking the Floor insulation topic I will just start another one. It is my understanding that at least one side needs to be unsealed to be able to breath to not trap moisture. My floor is painted which seals one side off. IMO I would consider installing any insulation under the floor sealing it off too. What is your knowledge and opinion about this?

Thanks,
Earnest

[tnriverluver]

If the location in your status is correct you should not need to insulate your floor. I camp in mine down into the 20's and the floor does not get noticeably cold as long as the heat is on in the trailer. Texas is generally warmer than Tenn. Toss a couple of small area rugs on the floor if your feet are that sensitive to the cold.

[cornfused]

I looked through your build thread. Since you have a roof vent and windows, I wouldn't worry about sealing it up too tight. You can always just crack the vent or windows if you need some fresh air.

[madjack]

...at this point and if you really wish to insulate, slip a piece of blue or pink(or even white) sheet insulation between your mattress and floor...tis what I did...........
madjack

[tnriverluver]

I will expand on my above post a little. Several years ago I had to tear all the insulation out from under my homes floors because of a rat invasion. I built my home myself and insulated the floors on the ground floor with some very expensive insulation designed just for that purpose. It was held in place simply by some stiff wires that popped in between the floor joist. Anyway a few years ago I opened the crawl space door to see if I could fine the cause of a foul odor that was developing in the house. When I opened that door and looked in, to my horror I found half the insulation laying on the ground and all of it was saturated with rat urine and poop! They had been nesting up in that insulation and were getting in by crawling up under my central unit and though an opening for the duct work. I tore all that nasty stuff out and cannot tell a bit of difference in the temp of my floors or in my utility bill. Floor insulating is a waste unless you are living in sub zero type climates IMHO.

[MtnDon]

As a builder of & adviser on building small cabins and homes for some time, many with raised floors, the question of floor insulation comes up a lot. In Hawaii insulation is hardly ever needed; most other places can use it at some time of the year. If the trailer is to used during those times it is my personal belief insulation in the floor is advantageous. Insulation will slow both heat loss and heat gain of course.

If this was a new, yet to be built floor on a new trailer it would be relatively easy to build a foam sandwich that is sealed as well as the walls and there would be little need to be worried about moisture issues. I would construct a perimeter frame with rigid XPS foam in the center. Sandwich with 1/4" ply on top and maybe the same on the bottom. CPES it all for weather protection. Add black goo if you want on the bottom.

If there is a floor in an already built TD it gets harder. Laying a sheet of XPS under the mattress looks after that area. A layer of the interlocking panels of foam rubber are nice for the other area. Or if losing a couple inches of headroom inside was no big deal, glue XPS to the existing floor and glue a 1/4" sheet of plywood on top of that. If I was going to insert XPS panels under the floor I would seal it in place with Great Stuff around the edges of each inserted piece of XPS. As long as that is done right and as long as the upper floor surface was painted / made water resistant there should be no way for moisture to enter the space where the insulation is. Of course there could always be some calamitous water leak from the roof but let's say that is prevented by good maintenance. Maybe protect the bottom of the foam with inserts of FRP glued to the bottom of the foam.

Back to cabins for a sec. The first year we had our cabin finished to where we could use it there was no floor insulation. The floor was okay until we got into fall. Then it was cool and in winter darn cold underfoot. Now with R19 even in the dead of winter it is warm enough for stocking feet after the first 24 hours goes by. Ceramic tile over cement board over OSB over the fiberglass. That floor has perimeter venting screened with 1/4 hardware cloth. No rodent issues. YMMV

[OverTheTopCargoTrailer]

I will expand on my above post a little. Several years ago I had to tear all the insulation out from under my homes floors because of a rat invasion. I built my home myself and insulated the floors. Floor insulating is a waste unless you are living in sub zero type climates IMHO.

This is why I love this form, there is always someone willing to give you their opinion , that negates the laws of thermo dynamics - heat transfer, based on anidotal evidence that rats really love to tear up Fiberglas insulation

[Prem]

A mattress is insulation enough for sleeping in my trailer.

I've slept in a down bag on snow on a 1/2" thick Ensolite pad without getting cold. (In the morning I woke up a foot deeper in the snow however.)

Last fall I insulated the floor in my house with 8" thick fiberglass rolls. WHAT A DIFFERENCE IN THE HEATING BILL! The house stays much warmer.

Just replaced the mouse-infested insulation in the ceiling of my rental. (Those renters were the worst ever. I had to kick them out.)

Good?

[MtnDon]

Well, mice and rats will make nests in fiberglass batt insulation. But only if they are provided access.

That is why ours has 3/8 plywood nailed under the joists (screwed in places where I might want future access, like plumbing). Costs more than leaving open but keeps out the rodents. 6 inch hardware cloth strips around the perimeter for any ventilation that might be needed. I'm not certain it needed that but if there is a calamitous leak it also gives an easy way for the water to exit. I forget the gauge number but it is heavy gauge galvy stuff that even rats are not supposed to be able to chew through. Hard to find. And yes, heat moves from hotter to colder; always has, always will, I suspect.

[hankaye]

MtDon, Howdy;

Not so hard to find;
http://www.lowes.com/ProductDisplay?par ... &cId=PDIO1

hank

[MtnDon]

MtDon, Howdy;

Not so hard to find;
http://www.lowes.com/ProductDisplay?par ... &cId=PDIO1

hank

I knew someone would make me look up the info I was too lazy to find last night.

The link does not specify the gauge of the metal. Rats can eventually nibble their way thru the commonly available materials at the hardware and home supply stores. Most of everything I see there is too small, 23 - 26 gauge, or if a large enough gauge has too large a hole size. Wire gauge should be 16 to 19 gauge to defeat rats. 1/2" mesh works for rats but mice need 1/4" mesh or smaller.

There is a National Park Service Rodent Exclusion Manual online. I can't finger the link but Google should find one no problem if anyone is interested.

FYI, we use steel Brillo pad like material and canned foam to insert into small openings that need blocking.

[OverTheTopCargoTrailer]

A mattress is insulation enough for sleeping in my trailer.

I've slept in a down bag on snow on a 1/2" thick Ensolite pad without getting cold. (In the morning I woke up a foot deeper in the snow however.)

Now I gotta run & take a hot shower

Just replaced the mouse-infested insulation in the ceiling of my rental. (Those renters were the worst ever. I had to kick them out.)

Yea , wish that I could poison or BURN OUT the Human RATS living across the street from my house

[eamarquardt]

.................heat moves from hotter to colder; always has, always will, I suspect.

Heat is energy. Cold is lack of energy. Something that doesn't exist can't move from one place to another. That "splains" it.

Cheers,

Gus

[roadinspector]

MtnDon,
Thanks for addressing the moisture question. I am already commited to having to do the inserts between frame members. I like the idea of XPS inserts sealed off with Great Stuff. If I do this I will wait till the heat of the summer when I know the humidity is down.

On the secondary subject of insulation that has been approached by others, I do like the lazy man's way (which I have considered) is put down area rugs as tnriverluver suggested. I would like to put down the interlocking foam but with hauling the bike when we go I am afraid the foam would not last long enough to offset the cost.

Thanks everyone for your input.
Earnest

[OverTheTopCargoTrailer]

I would like to put down the interlocking foam but with hauling the bike when we go I am afraid the foam would not last long enough to offset the cost.

Thanks everyone for your input.
Earnest

Earnest - the Dow Blue board is rated at 15 lbs per sq inch , lay down a 1/4 plywood NO PROBLEMO AMIGO !!

The white foam junk squishes like a bug