I am new to the business.  Went to a residence that has a mobile home that has an addition and metal roof.  This roof is about 8ft above the original mobile home roof at the ridge and extends passed the home to form a covered porch.  This roof is raining water from condensation on the old roof and ruining the new soffit not to mention all the other problems the water will cause.  The metal roof is uninsulated but has a white membrane of some kind (not Tyvek).  It has a vent on both ends 1ft x 2ft and some small openings on one side of the lower roof just after the porch roof.  The original roof has about 4" of fiberglass insulation.  The roof cavity is open and there is about 2 to 3ft  feet of clearance with no other obstructions.The addition has about a 1:12 roof that has fiberglass  insulation with a plastic covering that has been stuffed into the cavity filling it.  The water scares me for liability reasons but would like to help if I could.  Do I insulate the underside of the metal roof?  Do I blow in insulation into the old roof.  Do I foam the top of the existing? Do I walk away? Heat is propane wall units and fireplace.  Location Seattle

Views: 237

Reply to This

Replies to This Discussion

LOL, par for the course with some of these fixes for mobile homes - you are talking about a second roof added above the first one / not attached at all? The easiest fix is to install a system like one uses under the deck to drain water away - insulating it wont help. As for the addition part, you didn't really describe it all - pictures do help - so I cant even begin to guess on that

As for old roofs, insulating, etc... it all depends & as I said there isn't enough info. For more on Mobile Homes & tricks used - http://blog.sls-construction.com/2010/weatherization-program-modula...

I can't understand the situation very well, but you noted "propane wall units and fireplace".  I will bet that they are all unvented; burning propane produces a GREAT amount of water vapor into the living space, as well as the products of combustion(!!).  If that's the case, I would have them read the lots of negative information about unvented gas appliances, and if they don't change them, first for their own personal safety, second to stop the water production, then run away. 

A quote from one source I found: "Any amount of propane that you burn in a space heater will produce approximately 163 percent as much water."  Then there's the carbon monoxide(!!), oxides of nitrogen, etc.  all of which the living and breathing should not be living with.

Walk away. To be blunt, in my opinion, if you are asking these questions on this project, you should be starting with less complicated jobs.

Manufactured homes are not the same as stick built, although there are similarities. The bathroom vent fans are typically vented through the roof, which would be dumping warm moist air into the new roof cavity. I have found some manufactured homes to be rather tight, leading to higher Relative Humidity. Usually there is a furnace that is also vented through the roof, which may not be flashed properly or kept away from combustibles with the new roof. Did they properly extend any of these roof penetrations (flue pipe, stack vents, etc)?

Did they cut holes in the original roof? There are different ways to fix this, but the added metal roof will make it more challenging to resolve. Dense-pack cellulose is a possible solution, if done properly. Spray foam is not a solution, unless you are going to rip off the entire roof. 

Pictures are needed.... but honestly,  I'd walk away.  I live in Seattle area.  

If for some reason you need to stay with it and work on it...  you need lots of pictures - for your protection long term, and you need to test-in and test-out.

Adding any insulation without understanding the problem is going to cost you big time.

RSS

Forum Discussions

What made this chimney fall down?

Started by Eric Kjelshus in General Forum. Last reply by Eric Kjelshus on Tuesday. 7 Replies

How would you insulate this roof?

Started by David Butler in General Forum. Last reply by Dave Taylor Nov 11. 61 Replies

Manual J (SD) for custom, luxury homes

Started by Dav Camras in HVAC. Last reply by Dav Camras Nov 10. 3 Replies

Quantitative methods for residential zoning

Started by Brett in HVAC. Last reply by David Butler Nov 9. 1 Reply

Home Energy Pros and #MeToo

Started by Mike Rogers in General Forum. Last reply by Mike Rogers Nov 9. 3 Replies

Latest Activity

Profile IconSonny Roncancio and Chester Energy & Policy joined Home Energy Pros Forum
15 hours ago
Ryan Moore updated an event
Thumbnail

LEED for Homes Green Rater Training at Fort Collins, CO

December 7, 2017 to December 8, 2017
Green Insight will host this 2-day training in Fort Collins, CO December 7-8,…See More
yesterday
Rodney Bailey liked Rodney Bailey's discussion Energy audit equipment for sale.
yesterday
tedkidd liked Mike Rogers's blog post Focusing on payback to motivate customers?
yesterday
Home Energy Magazine's blog post was featured
Wednesday
Home Energy Magazine posted a blog post
Wednesday
Quinn Korzeniecki added a discussion to the group Building Performance Institute (BPI)
Thumbnail

Rebates and Incentives: Illinois

Curious about home performance incentives and rebates available in your area? Check out this BPI…See More
Wednesday
Profile IconStacey Cordeiro and Melissa Ames joined Home Energy Pros Forum
Wednesday

Photos

  • Add Photos
  • View All

© 2017   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service