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Use of insulation in the floor

PostPosted: Thu Apr 21, 2005 11:27 am
by Guest
There's a lot of talk right now about using insulation in the construction of the floor.
I decided some time ago, not to insulate my floor after reading this thread and the wise words of Cary Winch:
http://www.tnttt.com/viewtopic.php?t=1459&start=0

The way I understood Cary's words were, to eliminate the possibility of trapping condensation, which will cause wood rot, there must be no voids or air pockets when using insulation.
The mattress provides a good amount of insulation for the floor.
Maybe there has been a new technique or material as for the use of insulation in the floor, to my knowledge there has not... (If so, please advise me)
I will be using insulation in my walls and roof... With that said, I'm going to be very meticulous about fitting, filling and sealing any possible air pockets in the walls and the roof.
I'm not trying to be an alarmist, just trying to help and share what was given to me for free...

BTW- Here is the quote from Cary in that thread that sold me on this matter:
"Here is one that should stir up some controversy. Never, ever insulate your floor. Unless you get out all possible air infiltration areas and air pockets you will have condensation form in the floor cavity. This is the most likely place in the unit. This will cause rot in short order no matter how well you think you have it sealed. This also goes for belly pans and some gravel guards people try to do. From a warmth point of view all teardrops have an insulated floor called a mattress. We use 3" thick foam mattress and that is good insulation that is in the cabin safe and dry."

PostPosted: Thu Apr 21, 2005 11:50 am
by mikeschn

PostPosted: Thu Apr 21, 2005 12:14 pm
by purplepickup
I agree. If I find that I need insulation, like in my dropped floor, I'll insulate from the inside by using a mat type insulation like Low-E and put some foam backed carpet on top. Low-E is 1/4" foil faced with a polyethlyene foam core and it has a high R-value (not the bubble wrap stuff). I use it on car interiors as a noise deadener and heat insulator.

A plywood floor is so simple it seems a shame to make it complicated....for little or no gain.

PostPosted: Thu Apr 21, 2005 12:50 pm
by TomS
Per the Kuffel Creek plans, I coated the underside of my floor with asphalt emulsion. Then I installed rigid foam insulation before bolting the entire assembly to the trailer frame. I thought I did the right thing. Specifically, insulation would prevent condensation from forming under my foor and asphalt emulsion would prevent rot. That was Monday.

Now here it is Thursday. I'm reading that insulation under the floor is a bad thing and will cause it rot.

Ay ay ay! :?

This is like listening to those so called nutrition "experts" who's conflicting advice changes by the nano-second.

So..... What do I do now? Do I crawl under my trailer and rip out that insulation? Do I leave it in there? I'm sure others have insulated their floors according to the Kuffel Creek plans. Any Cubby owners out there experience rot problems with insulated floors?

PostPosted: Thu Apr 21, 2005 1:12 pm
by mikeschn
Tom,

I think if you used roofing tar (i.e. asphalt emulsion) and then put the insulation in, you'll be fine.

The insulation helps reduce the conduction of temperature thru the floor. And if you get water or condensation under there, the roofing tar will keep it from going any farther. Eventually the water will just dry out again.

So on to the next step!!!

Mike...

P.S. You could always add additional roofing tar in the cracks to keep it drier!!! :roll:

PostPosted: Thu Apr 21, 2005 1:31 pm
by IraRat
Tom, didn't you also use another coat over the insulation? That's in the Kuffel plans TOO!

PostPosted: Thu Apr 21, 2005 1:39 pm
by toypusher
Reading this thread got my curiousity up a little. Does Cary Winch put a double floor in his tears? I mean is there another piece of wood or aluminum under his plywood floor or uner the frame as I have seen some folks do? I that is the case, then I would agree with him. Otherwise, I have to disagree, because as someone else stated, the asphault seals the floor and any water and debris that gets up there then can not penetrate the wood. Polystrene insulation should be impervious to rot and decay, so the water should just evaporate and cause no harm.

Just my $.02 worth!

Kerry

PostPosted: Thu Apr 21, 2005 4:35 pm
by TomS
Thanks for clearing that up guys! :) This one really had me going there for a while.

Ira, I didn't overcoat the insulation. As Kerry said, the foam isulation is impervious to rot and decay. If you look at the the caption at the bottom of Page 23, it says to insulate after the asphalt dries.

PostPosted: Thu Apr 21, 2005 4:36 pm
by DestinDave
And something I've thought about but haven't looked into it very far... After waterproofing the wood and installing foam insulation what about stapling a layer of Tyvek housewrap tightly over the foam. This provides a vapor barrier on the outside of the foam, right? Any thoughts on this?

PostPosted: Thu Apr 21, 2005 7:48 pm
by Cary Winch
Asianflava is doing a composite floor with foam insulation in his. By eliminating the air doing it this way he should be safe. This would work well I would think. Besides, if done right would be very strong. If had to insulate the floor for some reason this would be the way to go. Still trying to understand why it needs to be done at all. Once again the mattress is great insulation.

Its not the insulation I have a problem with but the use of a double floor. Generally a double floor is done either to create a space to stuff insulation or for a gravel pan of some sort.

Cary

PostPosted: Thu Apr 21, 2005 8:20 pm
by asianflava
Check this thread, it has a lot of good information in it...even though the thread kind of runs away after a while. http://www.tnttt.com/viewtopic.php?t=1459

PostPosted: Fri Apr 22, 2005 8:01 am
by IraRat
TomS wrote:Thanks for clearing that up guys! :)

Ira, I didn't overcoat the insulation. If you look at the the caption at the bottom of Page 23, it says to insulate after the asphalt dries.


When I left the office and got into the truck, I realized I was mistaken. I don't know why that was stuck in my head.

Darn! I don't WANT to go to Disney tomorrow! I wanna BUILD and smell that gooey asphalt stuff!!

PostPosted: Fri Apr 22, 2005 8:10 am
by TomS
IraRat wrote:Darn! I don't WANT to go to Disney tomroow. I wanna BUILD and smell that gooey asphalt stuff!!


I've never been to Disney. The place will reminds me too much of work. When you get there say Hi to all my colleagues, Goofey, Dopey, Sleepy, Grumpy, etc. Of course everyone knows our CEO, MIckey Mouse. :lol: