Author Topic: Underneath a manufactured home  (Read 1401 times)

David Meiland

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Underneath a manufactured home
« on: June 21, 2011, 06:29:36 AM »
I was in the crawl space under a manufactured home, and am trying to make sense of how it was put together. There were concrete block piers supporting steel beams. There was a black fibrous panel material similar to homasote or sound-board covering most of the area and concealing almost everything from view, but I was able to look up through one damaged area and it appears that there was a floor frame of 2x6 over the steel. There appeared to be thin fiberglass insulation in there, along with all the ductwork. No insulation on the ductwork, and the fiberglass seemed to be sitting on top of the homasote rather than pushed up against the subfloor.

What is a typical measure for an assembly like this? Seems that the most thorough would be to remove the paneling and install a proper layer of insulation against the subfloor, and seal/insulate the ducts. I've got to imagine that a significant percentage of the heat is just lost under the building when the furnace is running. It did not look to me like you could just blow cellulose into this space, as it was fairly large, maybe 18" tall or more.

Any experience out there? This building had major energy bills, part of which is due to a hot tub.
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Bud9051

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Re: Underneath a manufactured home
« Reply #1 on: June 21, 2011, 07:40:07 AM »
My dad was in the air force and I grew up in one of the old trailers.  That combined with a few more recent experiences causes me to pass when the opportunity comes up.  It is really difficult to make major improvements on these boxes.  Pushing the insulation up next to the floor might block the heat that is currently in that cavity from keeping the floors warm.  Use less energy, but end up with cold floors.

Clint has a lot of experience in manufactured homes, but haven't seen him for awhile.  Might try to PM him to see if he gets an email.  If you still need help, I have a contractor on the internet I can contact, I know he was worked on a bunch of these.

Bud

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stnick

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Re: Underneath a manufactured home
« Reply #2 on: June 21, 2011, 10:20:32 AM »
David,

Are you talking modular, or a mobile home - which I think you are.  In KS you have to be certified specifically to do mobile homes.   

It sounds like you are talking about the belly board and what is under there.

I would wonder if this is the mostly permanent placement --  why you should do anything other than treat it as an enclosed crawl space and insulate the walls.  Probably a lot of leakage.  So  spray foam is a possibility.

http://www.efficiencykansas.com/auditors_forms.php

Go to the bottom of the page and down load the materials and information booklet.  There are some pages in there on mobile homes with illustrations.  The other forms we use are there and the Program Manual at the top has all the forms.

John  :)
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Tommy

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Re: Underneath a manufactured home
« Reply #3 on: June 21, 2011, 01:01:40 PM »
Sounds like a mobile home to me too.  The weatherization agencies here try to repair the belly to make it the air barrier.  Sometimes we add blown fiberglass (cellulose is too heavy), but we have to be very careful not to isolate any plumbing away from the heated space.

The worst duct leakage is usually where the boot joins the trunk line, and we seal that from inside.  If there are any other big holes in the ducts, we will cut open the belly to access them, and the repair it.

AuditTheWorld

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Re: Underneath a manufactured home
« Reply #4 on: June 21, 2011, 01:26:48 PM »
http://www.wxtvonline.org/
There is a good video of about taping and mastic duct work for mobile homes. We work on mobile homes all the time. For the most part if the particle board is in good shape we drill and fill with FG. If  it is questionable we will apply strapping to secure the particle board , then drill and fill. Always with fiberglass. Mobile homes are very easy to insulate. I know of some companies that have 30 foot fill tubes and fill each bay from the ends of the home and don't bother with the drill and fill method. If you would life specifics on how its done i can send it to you.

SLS Construction

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Re: Underneath a manufactured home
« Reply #5 on: June 21, 2011, 02:37:48 PM »
Wow, most of the ones I have seen have had a product similiar to landscaping fabric (which they actually use to repair or redo if needed)

Tommy nailed the way it is done down here with the exception of worrying about plumbing lines (those they might add insulation around if it is outside the belly fabric

Article I did on DOE's steps in our area- http://blog.sls-construction.com/2010/weatherization-program-modular-home

Tommy

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Re: Underneath a manufactured home
« Reply #6 on: June 21, 2011, 10:28:21 PM »
Wow, most of the ones I have seen have had a product similiar to landscaping fabric (which they actually use to repair or redo if needed)


Like this?   http://www.flexmend.com/__________Bottm_Board.html

That's what's on the newer ones here.

The older ones usually have a reinforced cardboard-like material, but I've seen a few that have homasote on the "wings", and cardboard type in the center.

Ram Page

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Re: Underneath a manufactured home
« Reply #7 on: June 23, 2011, 07:11:05 AM »
Check out Wxtv lots of good stuff on that site, and Cal Steiner is the mobile home GURU. In Vt we treat the belly as the air and thermal barrier. We airseal all the belly board( homosote, reinforced fabric ,ect ect, ) and then insulate the perimiter with a blown fiberglass to get the thermal break on rim joist area, This fills that void and some of course bleeds out into the middle ,But not so much as to  put the plumbing on the cold side of the insulation, be carefull of perimeter pipes to bathrooms and kitchens,and treat the main incoming waterline (heat tape,Styro box, pipewrap , dealers choice there). Huge energy savings and floors stay warm.
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