Quote:
Originally Posted by jungleboy
Your best bet is to go under there and spend the time to make the heat traces and insulation perfect on the piping. Even with insulation on the skirting you still need ventilation under there or you will eventually have mold issues, so its going to be pretty hard to prevent freezing temps under there.
Our last place was a mobile with well insulated and heat traced piping, we never had issues with freeze up. You need the heat lines to go below the ground level about a foot or more where lines come out of the ground to be effective.
My cabin has wood skirting and we had some mold under there within months of closing it in. I drilled holes for vents on all sides and that solved the issue
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This is exactly right.
You can not insulate and enclose a space as mentioned above.
The most common mistake is sealing off under a deck with a solid floor above, cabins and trailers.
Enclosed spaces must be either cold or warm but not some combination.
Cold spaces need to be cross ventilated. Warm spaces need to be properly ducted, in and out.
The space under a mobile home is designed to be a cold space and is to be ventilated. The membrane should be kept in tack or resealed if access is necessary.
Because it was mentioned and commonly done, Please do not drop a heat run into the crawl space area. The moist warm air will produce mold and other issues.
Modular type duct systems are balanced and run at a higher static pressure than a house furnace. Basically, the main run is all the same size and is pressured up to deliver equal air flow to all registers.
There is no extra pressure or volume to dump heat runs into an addition for example. You rob Peter to pay Paul. Air flow will be reduced across the trailer and the furthest rooms from the furnace will most often become very cold.
At the same time temperatures drop above the membrane in different places like ensuites and under kitchens.
If you happen to be changing the furnace out at the same time as making an addition you could add a bigger furnace that was made to move more air. But again, the addition would have to be part of the house and the membrane must be kept in tack or resealed afterwards.
The furnace itself is the return air for the entire trailer. This is why there is such big a space under the doors etc.. It allows air to travel back to the furnace and be recycled as return air.
Dumping air out of the main shell of the home creates problems. Because we have air leaving the trailer that shouldn't be, the pressure can become negative.
Add a range hood, turn on the dryer and all of a sudden we have gas appliances back drafting.
Every year we get dozens of calls from people having major trouble in trailers during cold snaps. More often than not someone was under the trailer screwing with duct work or plumbing with nothing but good intentions.
Mobile home insulated skirting
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