# Attic insulation in manufactured home?



## Pafrmboy (Oct 10, 2014)

I have a friend asking me about adding some attic insulation to his vacation home that is manufactured.

This home has a 2x4 framed attic trusses , shingled roof with 4/12 pitch. 14' X 70 ' home. The interior ceilings are NOT vaulted and are flat. There appears to be R19 laying on the ceiling, but it has gaps and such and could use some improvement. 

Access/venting is at the front and back gables only. There is a ridge vent on the home. No fascia venting.

Questions:

If blown-in is added, it will touch the roof underlayment near the roof/wall connection. Is that ok? (It can be blown in through the gable assess and possibly some interior access openings).

Will venting of the space be sufficient with just the 2 14" X 14" gable vents an ridge vent, or should turbines be added?

How can you control insulation from being near/covering areas like furnace chimney, etc?

How much do you think should/could be added?
(Home is in Northern Pennsylvania).

Thanks much, Todd


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## Tinstaafl (Jan 6, 2008)

First off, the venting is screwy. Gable vents in conjunction with a ridge vent means that a good portion of the venting gets short-circuited and doesn't really do its job. The better way is vented soffit feeding air upward along the underside of the roof sheathing to the ridge vent, and no gable vents at all.

As for controlling where the blown insulation lands, that's not all that difficult. Similar to spraying water with a garden hose, you can be pretty precise in most cases. For the exceptions, just wade in and scoop it away from the areas you don't want covered.


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## Pafrmboy (Oct 10, 2014)

I'm not so sure if fascia vents could be added. Not much, is any overhang. I will take a look again at it.

Thanks for the feedback.
Todd


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## SLSTech (Sep 13, 2008)

All I can say is that weatherization crews blow the cavities full with cellulose or fiberglass and don't worry about the venting - as for long term results...


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## dielectricunion (Feb 27, 2013)

Staple up baffles where insulation might contact the roof deck, or make your own


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## Pafrmboy (Oct 10, 2014)

I wish I could put up baffles, but there is no space to get down in there to do that. I suppose I could just position them down.

I am going to look closer at this job next week.


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## slowsol (Aug 27, 2005)

What difference does the baffle make if it's not pulling air from the eave (or lack of eave)?


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## intersound2005 (Jan 1, 2014)

Manufactured homes roofs are just asking for problems, low pitch, poor insulation, no vents, no eaves soffit, means warm roof that melts snow here in MI, massive ice damming accurs. I worked on one that was around 20 years old, water ran off roof, down the face with no overhang, icicles all the way down frozen right on the vinyl, gets behind the siding, runs down horizontally, and rots the wall out. Ive seen this in multiple double wide homes. If It were mine and i was forced to live in it, id be tempted to blow the small attic cavity full with cellulose, and install a metal roof with a few inches of actual overhang.


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## Pafrmboy (Oct 10, 2014)

Actually, I think he was considering a metal roof....but down the road.

The home is actually a really nicely constructed home, but yes, the roof assembly could be improved upon.


Here's his plan. Tell me what you think.

1. Blow cellulose into the attic from both gable vents and interior access as best as possible. Trying to not pack it in too tightly at the sidewall/roof connection.

2. Increase the size of the front gable/rear gable vent as much as possible.

3. Install 2 spinner turbines, or additional venting in the roof. (Maybe 4 or 5 vents, vs 2 spinners. (This is in addition to the ridge vent).

4. Do you guys prefer cellulose, or fiberglass?
and....would it be bad if at the wall/roof connection, the insulation touches the roof underlayment?

Thanks again.....


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## intersound2005 (Jan 1, 2014)

Installing spinners isnt going to do much if anything, neither will all the extra vents. Theres NO eves overhang so allowing a baffle gap isnt going to do anything. If there is still a cavity left after you get done blowing insulation, then yes, your current gable or ridge vents will help some.
You probably have 4 luvered vents as well on mfc homes. You have enough vents, problem is is that air cant travel from eaves soffits because there arn't any. 
Best solution is to keep heat loss to a minimum to start with.


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