Insulation question

[atcNick]

I'm insulating my trailer with prodex and insulation board. Do you guys cover the "ribs" with anything? It's 100° outside and they're pretty warm to the touch on the inside of the trailer even with the AC running

[OverTheTopCargoTrailer]

If you want the best insulation check my build ,
You can cool 7 x 18 in 100 deg full sun only with 5,000 window AC
Same with the heating, it's just a matter of what is cost effective in your case.




http://overthetopcargotrailer.blogspot.com/

[jwhite]

I used 2 layers of foam board and it was flush with the metal studs, I am sure that is enough but I sealed all the spaces with grey duct tape, it's cheap and just looked more finished.
I covered it back up with the plywood and covered that with carpet and bead board on the ceiling.

[roadinspector]

I put duct tape over my wall studs. It was supposedly good tape but about 25% of it dropped off as I was putting the plywood wall covering back up. I did not replace those pieces. My thinking on that is 1: screw it, I got other rabbits to kill that are more important, 2: I considered that it would help with air flow inside the walls hoping to help keep condensation from forming. I am not having any probs with temps with a 5050 btu unit cooling my 7x7x16. I can't hang meat in there but I am very comfortable when working in it.
Hope this helps. Good luck with your build.

Earnest

[Treeview]

Are your ribs Z channels or tubing?

If they're tubing you should consider using foam in a can insulation to fill the voids and break the thermal bridge.

The ceiling 'joists' in my ToyBox are rectangular aluminum tubing. I drilled holes in them so that I could get the nozzle to the right and left then squirted. After doing that I could touch the joists that were insulated but not the sheathing/aluminum roof. The hollows that I haven't foamed or encased with insulation are VERY hot compared to the ceiling joists or places that have insulation.

Tom

[OverTheTopCargoTrailer]

If you decide to go nuts with the foam,
Make sure it's non expanding foam, or your exterior will have bumps & lumps.

I did my door to fill the voids and it looked pregnant when I was done

Good luck

[OverTheTopCargoTrailer]

PS Earnest

Isn't 110 deg about normal weather for TEXAS ?? In the summer

I thought you don't need AC until at least 120 deg F at 10 am morning

With all my insulation my 7 x 6 x 18 has now become a 6 x 5 x 16 ,
Maybe that's why the AC works sooooo good

LOLROTF !!!

[Treeview]

With all my insulation my 7 x 6 x 18 has now become a 6 x 5 x 16 ,

You're pulling a foamie now

Tom

[grantstew8]

Hi
It is all about priority and budget. This is not a house you'll need to keep cool 24x7x365 so you may feel that it's not worth the extra cost/time. We had this a lot with steel and sips building.

If you fill a tube with foam it does nothing. The inside is insulated but the heat/cold is transferred around the insulation by the steel, there is no physical break. One problem we have here (uk is cold not hot) is condensation on the inside. Warm moist air comes in contact with cold steel and you get a condensation drip.

In you case insulating from the outside is not possible now so a thin layer of hyper performing (read expensive) insulation over the steel tubes would do the trick.

There are some paints that are good insulators used in the ship/submarine world. Again these are eye watering prices

If all else fails, a thin layer of foam is better than nothing.....

[len19070]

If you fill a tube with foam it does nothing. The inside is insulated but the heat/cold is transferred around the insulation by the steel, there is no physical break.

I'm with Grant on this. Metal, as in your metal studs is a conductor and not an insulator.

If its Hot/Cold on the outside, its Hot/Cold on the inside.

As it looks now the only insulating break you have is the Plywood.

One thing that may help is if you finish off the inside walls with some kind of Foam Backed Rug over the plywood.

But also, very important cover the metal with something that won't let Moisture transfer through to the Plywood.

Happy Trails

Len

[OverTheTopCargoTrailer]

Here is how you build a foamie trailer

a wood wall pic.JPG (135.07 KiB) Viewed 5032 times

photo 1-2.JPG (141.46 KiB) Viewed 5032 times

double foam wall.JPG (99.53 KiB) Viewed 5032 times

JUST DONT ask what it costs

[Willuz]

I used extra wide Gorilla tape to cover the studs and hold the insulation in. It sticks great even in extreme heat and it's thick enough to provide some insulation between the plywood and the metal stud. The most important place to seal is the top of the insulation, otherwise the hot air just rises up and out the top into your trailer.

[jwhite]

The Gorilla tape is Great Tape it cost more but worth it, it's thicker and really sticks to anything.
I had never used it until I built my trailer, now I keep a roll around for everything.

[grantstew8]

I used extra wide Gorilla tape to cover the studs and hold the insulation in. It sticks great even in extreme heat and it's thick enough to provide some insulation between the plywood and the metal stud. The most important place to seal is the top of the insulation, otherwise the hot air just rises up and out the top into your trailer.

Thermal bypass is a major issue where air is able to flow from one side of the insulation to the other and in essence makes the insulation almost useless. What Willuz says is important.

If you are building a house, I can't stress how important it is to avoid thermal bypass. The position of the insulation within the wall/roof and seal of insulation is vital or it's a waste of time/money and will cost a fortune to heat/cool.
It's been a soap box of mine for a while.

I could bore y'all senseless but the essence of it is, make sure the insulation is in tight and sealed with tape.

[OverTheTopCargoTrailer]

Grant my Bro -

We are beating a dead horse over here, they all just slap up 1" el cheapo $100 worth of foam between the metal studs with some duct tape
Some even think they get R35 with the 1/8" silver plastic bubble wrap
and then they fire up the old 13,000 Btu ac & 40,000 Btu heater buddy and swear how good it works
most can't even see the condensation pouring from the walls , its on the back side of the plywood.

Psssssssst , for heavens sake don't wait for them to do the floor , side door or the large rear cargo door
those never loose any heat ....

sooner or latter, with some dumb luck we will find a convert,
but when he finds out what that DOW Blue board costs he will get scared off
The cost for 3" dow Blue board on 7 x 18 is around $1,000

Cheers Jerry