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Old 12-09-2014, 05:08 AM   #1
ltoews
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Underbelly Insulation

I would like to add some insulation in the underbelly. The thin bubble wrap does not provide much in the way of insulation as I have had a couple of valves freeze. I tried a search wondering if someone had already posted on this subject, but no luck finding anything. It looks like the underbelly can be dropped in sections and do one section at a time. Has anyone added insulation and if so, what type and were there any special things to watch out for?

Thanks for the replies,
Larry
 
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Old 12-09-2014, 06:20 AM   #2
dieselguy
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I've added just regular bat insulation like's in the attic of your house more so towards the rear of the main living area, but I don't know if it really did anything. I seldom winter camp. You will have to allow at least a passageway to the galley tank and fresh water tank for the little furnace duct to do what it's designed for. The main tanks lay right at the bottom of the dropped frame, so there's not much room for insulation below them. I have seen people put 2" thick styrofoam strips inbetween the floor beams above your storage compartments. The main thing is to keep any valving or lines away from direct contact with the steel frame as it will always freeze in the area in contact with the cold steel. Thinking a bit differerntly, if I were in need of cold weather under belly protection ... I think I would look into the heated tank option.
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Old 12-09-2014, 06:30 AM   #3
twindman
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I think the best way to keep the underbelly from freezing is to move south!!!
Sorry I couldn't resist as I live in Arizona.
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Old 12-09-2014, 07:09 AM   #4
bigskyjimmy
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If you plan on being in the Dakota's for a while in the Winter you might want to check into getting some Skirting around the 5er but I don't worry about it much about my tanks,lines valves etc.. freezing if you do the right things, I have fulltimed in the Winter for 4 years now and while it does not get down to zero degrees like it does in the Dakota's but up here in the NW it still gets pretty dang cold ,just make sure at night you leave the heat on about 55 to keep the chill off in the underbelly for the tanks ,heat tape and foam wrap on EVERY INCH of the fresh water line and Spigot and if it is REAL cold I will put a small electric heater in the basement by the conveience center and then Good to go! IMHO I think the foil insulation and black underbelly cover do a pretty good job keeping everything from freezing at least on my 2012 and my 2015 Monty,also we are lucky at our Resort we have free electricity so we don't use too much Propane but still get ready to burn thru it pretty good if it gets Real Cold
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Old 12-09-2014, 07:29 AM   #5
richfaa
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remember about adding house type insulation in the underbelly. When the tanks leak or burst and there is a high probability that they will , you will have a soggy, stinking mess. Been there done that.
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Old 12-09-2014, 02:48 PM   #6
DQDick
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That would also be my concern. Damp batting insulation actually doesn't insulate but can actually work to transmit the cold.
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Old 12-09-2014, 03:36 PM   #7
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Quote:
quote:Originally posted by richfaa

remember about adding house type insulation in the underbelly. When the tanks leak or burst and there is a high probability that they will , you will have a soggy, stinking mess. Been there done that.
Not always. Have had montana units since 2002, full timed for six years, spend 5 to 6 months in Florida each of the past 8 years and have had one gray tank failure easily repaired by myself in all those years.
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Old 12-09-2014, 04:38 PM   #8
dieselguy
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Even the super duper 1/4" foil will wick up water. In 2011 when I was on my creeper under my brand new unit in the dealers prep lot during the PDI, I noticed the plastic underbelly sagging down. The prep crew for my fiver pressure washed my underbelly for some unknown reason. When I pushed up on the plastic belly material, water ran out both ends. It got into each and every channel in the corrugated plastic underbelly material and also go into the super duper 1/4" foil insulation material. It seems the foil insulation material (at least mine) has thousands of tiny holes in it from the manufacturing process. It was similar to a big sponge when I removed it from the underbelly. Fearing never drying out before forming mold, I replaced the foil insulation and the dealer reimbursed me. Why I didn't make them do it then and there? Read some of my archived posts on the faith I have in any dealers service departments and you'll figure it out right away. I did it in such a way that there were no cuts in the belly pan plastic.
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Old 12-10-2014, 01:04 AM   #9
WaltBennett
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I added more Thinsulate to the front underbelly, but haven't gotten to the rear yet. Don't know how much it's helped as that part is under the basement. I wouldn't use fiberglass due to what's been stated above - and there's also the potential for water to get in from gaps (look around your suspension) and the sides from rainwater.
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Old 12-10-2014, 02:28 AM   #10
richfaa
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You are correct Mike but you had a tank failure. We have had 7 thus far in 8 years of long timing.
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Old 12-10-2014, 07:01 AM   #11
Flymutt
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I didn't add insulation but did use a can of spray foam to fill in the gaps (from the underneath side). There were plenty of open spaces on my '05.
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Old 12-10-2014, 09:53 AM   #12
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I crawled under mine a month or so ago when it was starting to get really cold. There were some spots where the factory had used foam spray insulation, like around drain pipes and such. I trimmed these area plus I found some other little cracks that I filled with a high quality OSI silicon sealant. I just figured by making it as air tight as possible I would let the furnace put some heat in there.
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Old 12-10-2014, 11:39 AM   #13
Tom S.
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Quote:
quote:Originally posted by richfaa

remember about adding house type insulation in the underbelly. When the tanks leak or burst and there is a high probability that they will , you will have a soggy, stinking mess. Been there done that.
Exactly what I was going to say! I'd go with some type of foam board.
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Old 12-11-2014, 02:51 PM   #14
ltoews
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We are already south in the Houston area and will head west to Arizona after Christmas. We have family in Kansas so we occasionally spend time where it gets cold. We have skirting and use it when we need to.

Since the temperatures have been warm here recently, now is a good time to prepare for the next time we are in cold weather. I too have noticed several gaps and openings that allow cold air infiltration. Closing those openings and adding some foam board sounds like a good improvement.

Again, thanks to all for your ideas.

Larry
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Old 01-03-2015, 09:38 AM   #15
Chasnracin
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My concern would be that the insulation would create a blockage and have a lack of flow of "warm" air. Am I imagining that?
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