Adding exterior underlayment?

Repair help for the do-it-yourselfer.
For mobile home parts, click here.

Moderators: Greg, Mark, mhrAJ333, JD

Locked
Lorne
Posts: 368
Joined: Sat May 19, 2007 7:57 am
Location: Murrells Inlet,SC

Adding exterior underlayment?

Post by Lorne » Fri Jan 29, 2010 11:23 am

I had posted this on another thread talking about electrical costs, but deleted it and started a new thread.
I feel lucky cause our bill only jumped $20, from $137 this month last year to $157 this year.
Here in SC some bills have doubled on some folks.

Our double wide has NO exterior underlayment, just insulation between 2x4's ,NO vapor barrier and then vinyl siding.
Would it be a good idea to strip off the siding, add plywood underlayment plus Tyvec?

It would be costly but how effective would it be?
Maybe replace insulation with Foam?

It seems that bills will continue to increase, so maybe the investment would pay off.
Any thoughts? on a 34x40 DW?
1987 Craftsman Double Wide 42x28,w/attached 28x12 foot enclosed porch/ re-shingled 2 yrs ago. Original exterior vinyl w/no sheathing.


User avatar
Robert
Moderator
Posts: 6413
Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Re: Adding exterior underlayment?

Post by Robert » Fri Jan 29, 2010 10:38 pm

Hi,

It would help greatly as it would stop air infiltration, reduce heat gain/loss and also protect home from moisture and give better support during storms.

Being a SC native, I'm very familiar with weather patterns there. I was vacationing in your neck of the woods in October at North Myrtle Beach.


I'm going to move this to the mobile home repair forum for more attention.

Please follow it there.


Take care and best wishes,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?

Lorne
Posts: 368
Joined: Sat May 19, 2007 7:57 am
Location: Murrells Inlet,SC

Re: Adding exterior underlayment?

Post by Lorne » Sat Jan 30, 2010 5:40 am

Thanks for the input.
There have been reports of utility bills doubling down here using Santee Cooper, but the radio report didn't go into much detail.

Other reports are that if "Cap & Trade" were to become fact that everyone would pay through the nose. Right now this is only from political talks.

If it would cost $5,000 or $10,000 to re-clad the out side, then it might be worth it over a long period.
Any "rough" idea of cost to do this?
I know that the labor cost would be a large part of the bill.
1987 Craftsman Double Wide 42x28,w/attached 28x12 foot enclosed porch/ re-shingled 2 yrs ago. Original exterior vinyl w/no sheathing.

User avatar
Greg
Moderator
Posts: 5631
Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY
Contact:

Re: Adding exterior underlayment?

Post by Greg » Sat Jan 30, 2010 11:09 am

My only concern would be a possible weight issue. I would stay with 3/8" over 1/2" and remember to tape the tyvec seams. $10K sounds high to me unless you are planning on new siding also. Greg
"If I can't fix it, I can screw it up so bad no one else can either."

ponch37300
Posts: 622
Joined: Tue Nov 11, 2008 6:12 pm
Location: wisconsin

Re: Adding exterior underlayment?

Post by ponch37300 » Sat Jan 30, 2010 3:48 pm

I'm far from a mobile home expert, these things continue to puzzle me everyday on the ways they are put together but I do have a far amount of knowledge in construction and have built a couple of garages. I know that the sheating provides a great deal of strength to the walls. When a wall is standing without sheating it can still be moved and pushed around. Once the sheating is installed the wall will stay square and it adds a great deal of strength. There has to be some other kind of bracing on your trailer to provide this support, maybe diagonal bracing in the corners or something.

I would think the insulation in your walls should be good enough depending on how thick it is, you shouldn't need foam insulation unless you want to spend the money. Foam is nice and air tight but also expensive so would take a lot to get that money back in energy savings. If your home is structurally sound now and you don't "need" the sheating for structure purposes you could look into ridgid foam for the exterior and then side over it. Would give you a vapor barrier and when you tape the seams it will protect you from the wind. You wouldn't need to tyvec then since the foam is a vapor barrier itself.

This is also something you can do yourself pretty easy if you feel up to it. Just have to take the siding off and nail on the foam and tape the seams. Foam cuts with knife. Then install the siding again. So you could save all your labor costs which you said would be the majority of the cost.

Hopefully someone will correct me if my thinking is wrong.


User avatar
Greg S
Posts: 541
Joined: Wed Jun 18, 2008 10:13 am
Location: Kingston Ontario Canada

Re: Adding exterior underlayment?

Post by Greg S » Sat Jan 30, 2010 5:36 pm

With your present bill at $157 it is unlikely the cost to pay someone to do the work would be recouped from the savings in your life time.

Possibly if you did all the work yourself and your existing siding was reusable it may be worth the expense but more importantly the home may be more comfortable with the addition of sheathing and tyvec.

Seems like far too much work considering the small savings you may gain.
An individual must enforce his own meaning in life and rise above the perceived conformity of the masses. (Anton LaVey)

User avatar
Yanita
Moderator
Posts: 3369
Joined: Sat Feb 17, 2007 10:16 pm
Location: Eastern N. Carolina

Re: Adding exterior underlayment?

Post by Yanita » Sat Jan 30, 2010 10:39 pm

Remember to consider that when you remove the siding and add a sheathing then replace your vinyl you will have to come up with creative trim...your windows will be recessed after.

Yanita
The difference between success and failure is who gives up first!

Lorne
Posts: 368
Joined: Sat May 19, 2007 7:57 am
Location: Murrells Inlet,SC

Re: Adding exterior underlayment?

Post by Lorne » Sun Jan 31, 2010 8:44 pm

Some really good food for thought and Yanita brings up a good point about the thickness adding to the outside dimensions, fatter house. Thanks all.

Our heating bill would be a lot higher if it weren't for the upgraded heat pump.
Summer is coming, OH BOY.
1987 Craftsman Double Wide 42x28,w/attached 28x12 foot enclosed porch/ re-shingled 2 yrs ago. Original exterior vinyl w/no sheathing.

Locked