DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   Insulation help. (http://www.diychatroom.com/f19/insulation-help-91566/)

neva_2l82_learn 01-06-2011 10:44 PM

Insulation help.
 
We recently purchased a home that we are remodeling. The frame is 2 x 4 walls. The home has been almost completely gutted. We are looking for the best way to add insulation and increase the r value. The home is 2 stories. We removed all of the drywall and will be replacing it. The walls are insulated with rolled, faced fiberglass insulation that is in pretty good condition. However, it is only r11 on the main floor and r13 on the 2nd floor. There is no vapor barrier. There is no siding on the house right now, but it is already wrapped with Typar house wrap. Are we right in our thinking that we need to add more insulation? What would you suggest from an economic standpoint and for the least amount of headaches? Should we fur out the walls, spray foam insulation, or add foam board to the outside? It seems a shame to tear out the fiberglass insulation that is already in the walls. What do you think?

Gary in WA 01-06-2011 11:05 PM

Where is the house located?
http://www.diychatroom.com/f98/how-b...ulation-90438/

Gary

neva_2l82_learn 01-06-2011 11:07 PM

In Eastern Iowa.

jklingel 01-07-2011 02:42 AM

Vapor barrier: Before you install one, make sure you need one. More than likely you'll be better off w/out one. Your code probably says "one perm or less" and there are ways to do that and not get the risks associated w/ vapor barriers in marginal climates. The Airtight Drywall Approach is one. If you ever run air conditioning, the VB may kill you; condensation from the outside. As for the FG insulation: A shame to throw it away? IMO, it is a shame to leave it there. While you are at it, replace it; check on cellulose or cotton batts instead, or, if you want to fir out, double wall and dense pack cellulose. Search here, and on buildingscience.com for more info. j

IHICH2011 01-07-2011 03:58 AM

Quote:

Originally Posted by neva_2l82_learn (Post 564470)
We recently purchased a home that we are remodeling. The frame is 2 x 4 walls. The home has been almost completely gutted. We are looking for the best way to add insulation and increase the r value. The home is 2 stories. We removed all of the drywall and will be replacing it. The walls are insulated with rolled, faced fiberglass insulation that is in pretty good condition. However, it is only r11 on the main floor and r13 on the 2nd floor. There is no vapor barrier. There is no siding on the house right now, but it is already wrapped with Typar house wrap. Are we right in our thinking that we need to add more insulation? What would you suggest from an economic standpoint and for the least amount of headaches? Should we fur out the walls, spray foam insulation, or add foam board to the outside? It seems a shame to tear out the fiberglass insulation that is already in the walls. What do you think?

Hi,

You guys are doing a great job!!...

I notice that you have Kraft paper faced insulation on the in side of your home and a Typar vapor barrier on the outside? Correct?

If this is the case...you have the correct vapor barriers in place. The paper kraft paper is a vapor barrier on the inside. Once you flip over and staple that paper to a stud...you have created a seal. The Typar barrier on the out side is also a vapor barrier. You have a wall that is now properly sealed. All you have to do is side the house!

What type of siding are you going to install? This can sometimes dictate how you insulate.

If you want more insulation R-Value you really should have preplanned and thought about the siding first!

Some sidings require insulation be added during installation, such as steel siding.

If you add insulation over the Typar you will be adding a double vapor barrier and could create a "Big" mold problem for sure!

Check this out with your contractor right away!!!!!

Good Luck!
IHICH2011 - I Hope I Can Help 2011!!
:thumbup:

neva_2l82_learn 01-07-2011 06:05 AM

The house we purchased was a foreclosure and the typar was done before we bought it. We our planning vinyl siding. So, is r11 and r13 enough for eastern iowa with the typar and vinyl insulation on the outside?

IHICH2011 01-07-2011 09:21 AM

Insulation Help.
 
Hi,

You have 2x4 walls and have insulation in place. R11 is all that is required because of for your wall thickness and when it was built this was the norm. Up grading the insulation will depend on how long you plan on staying in the home or if you are fixing to sell.

You may want to up grade that insulation if you plan on staying for a while. Your cost to remove and re-insulate may not be worth it if you plan on selling in 5-10 years. Your savings through heating and cooling may not equal the cost to re-insulate.

You can do better than R11. You can now purchase Kraft (paper) faced insulation in R13 & R15 for 3-1/2" walls. The most you can put in a 3-1/2" wall is with spray foam max R20-22.

Good Luck!! :thumbup:
Mike IHICH2011

hereslookingatU 01-07-2011 07:04 PM

Hi

If you want to do a good job, go for 50mm [2"] PIR Insulation between studs finished flush to face of studs and then add a thermal clad plasterboard finish board [Kingspan k18 comes to mind - although there are other manufacturers who produce a similar product - possibly come down to cost implications]. Again use 50mm (aprox) PIR insulation + plasterboard finish at 12.5mm [1/2"].

PIR has a relatively high vapour resistance and there is no need for a vapour barrier, as an added benefit you may wish to consider fixing a foil to the studs before you fit the k18 this provides some benefit by reflecting back some of the heat into the face board.

To finish tape and joint and decorate.

Also there will be a void where you can run services, such as electrical/audio cables/central heating pipework prior to fitting the insulation.

Job done :whistling2:

Regards

High Gear 01-07-2011 09:28 PM

What type of heating fuel ( also efficiency of furnace )you are using should

be factored into this also.

If your lucky enough to have NA/gas ( relatively cheap ) and a 90+ efficient

furnace your insulation upgrade payback would be longer as your fuel bills

are already lower.

Propane electric or fuel oil, different story.


Insulation wise, there may be state ( currently federal tax incentives but

they have changed for 2011 )tax incentives also for upgrading insulation .

Payback aside your comfort is a factor also ..at least mine is.




.

neva_2l82_learn 01-07-2011 10:11 PM

Furnace
 
Quote:

Originally Posted by High Gear (Post 565218)
What type of heating fuel ( also efficiency of furnace )you are using should

be factored into this also.

If your lucky enough to have NA/gas ( relatively cheap ) and a 90+ efficient

furnace your insulation upgrade payback would be longer as your fuel bills

are already lower.

Propane electric or fuel oil, different story.


Insulation wise, there may be state ( currently federal tax incentives but

they have changed for 2011 )tax incentives also for upgrading insulation .

Payback aside your comfort is a factor also ..at least mine is.




.

We have a new LP 90 percent effecient furnace as well as an outdoor wood furnace. Our plan is to use the outdoor wood furnace as much as possible.

neva_2l82_learn 01-07-2011 10:16 PM

staying forever
 
Quote:

Originally Posted by IHICH2011 (Post 564624)
Hi,

You have 2x4 walls and have insulation in place. R11 is all that is required because of for your wall thickness and when it was built this was the norm. Up grading the insulation will depend on how long you plan on staying in the home or if you are fixing to sell.

You may want to up grade that insulation if you plan on staying for a while. Your cost to remove and re-insulate may not be worth it if you plan on selling in 5-10 years. Your savings through heating and cooling may not equal the cost to re-insulate.

You can do better than R11. You can now purchase Kraft (paper) faced insulation in R13 & R15 for 3-1/2" walls. The most you can put in a 3-1/2" wall is with spray foam max R20-22.

Good Luck!! :thumbup:
Mike IHICH2011

I'm hoping this will be the last home we buy, so we plan to live in it for a long time. We got a quote for spray foam today. It came in at $7,200.

Gary in WA 01-07-2011 10:55 PM

SPF is the best yet. Other than thicker walls.... The link on insulation I gave shows your local requirements and that R-11 is garbage with convective loops. Typar is ok as it is a water resistive barrier, not a vapor barrier. The paper faced insulation is a vapor retarder, not barrier, with a permeability close to plywood sheathing. http://www.energysavers.gov/your_hom.../mytopic=11810

Gary

jklingel 01-08-2011 02:30 AM

Quote:

Originally Posted by GBR in WA (Post 565265)
The paper faced insulation is a vapor retarder, not barrier, with a permeability close to plywood sheathing.
Gary

And I would add that you won't ever get the edges perfectly installed, so it is not great at retarding much, IMO. Better than stink, but not great. Typar has a perm rating of about 12-ish, so as mentioned it is a vapor retarder. (visqueen is about 0.06). Another "IMO", the comfort factor mentioned above is a very good point, and when you go to sell, if you do, your lower heating bills ought to be a big plus. I think people are getting more and more aware of saving on the bills, so "Insulate, man, insulate!" If you do use rigid foam between the studs, make sure you spray foam ("greatstuff" etc) the edges/gaps, and I think the foam outside the stud bay is the best, not toward the sheet rock. If toward the sheet rock, I am certain you'd get conductive looping and greatly reduce the overall wall R-value. Have fun w/ whatever you figure out. j

hereslookingatU 01-08-2011 05:31 AM

Hi

On a personal note I would leave spray foam right out of the equation as you will need to keep an air gap between the insulation and the outer building fabric as this is where the condensation zone will occur, (hence the 2" thickness between studs) and as every good scout knows (or at least should know) moisture, timber and lack of ventilation do not make an ideal mixture - could easily end up with timber decay which by the time its identified would cost a fortune to rectify.

Another word for condensation in the above scenario would be 'sweating'!:whistling2:

Regards

jklingel 01-08-2011 01:05 PM

I also worry about moisture getting to the sheathing w/ spray foam (either vapor from the inside, liquid water from the outside, ie, leak, or solar vapor drive), but they do spray closed cell foam against roof sheathing for cathedral ceilings. I guess it works... spooky, to me.


All times are GMT -5. The time now is 11:04 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved