Is foam insulation worth the cost?

[MTG#10]

I just purchased a new home that is more than double the sq footage of my current. One of the things the inspector noted was my attic insulation was a little under the recommended amount for the location its in. My mortgage is already going to be $300/month more than I'm currently paying and since the house is so much bigger obviously the electric will be a lot higher as well.

I have already gone through the entire house and changed all bulbs to LED. Ive checked all doors and windows and they all have good seals. My next step is to replace the loose insulation in the attic with foam. Or keep it and have the top of the attic sealed with foam, whichever would work best.

Has anyone had this done to an existing home and if so how much did it cost? Was the utility savings noticeable and worth it?

[Chief Roundup]

Cellulose is ok but it settles bad. If you put cellulose in walls it will settle. In about 10 years there will only be a couple of foot in the bottom of the wall cavities.
Foam is good but expensive. You also have to be careful. If you foam everything you will have to put in some type of an FAV system to bring in fresh air or you will have problems.

[Chiefaholic]

Originally Posted by Pablo

Smart.

I started throwing my crusty jizz socks in the attic. Don't know if it helps with the bills but the whole house always smells like mushrooms. So that's nice.

[Molitoth]

Originally Posted by Chief Roundup

Cellulose is ok but it settles bad. If you put cellulose in walls it will settle. In about 10 years there will only be a couple of foot in the bottom of the wall cavities.

The professionals use a perfect water mixture to blow cellulose in wet, which activates the stickiness in the paper. This will not settle if done right.

Go to Lowes and rent your own blower and do it yourself? It's going to be messy as hell, and settle badly.

Foam is good but expensive. You also have to be careful. If you foam everything you will have to put in some type of an FAV system to bring in fresh air or you will have problems

The first Inch of Foam acts as a great vapor barrier. After that, it's not anymore R-value than cellulose from what I understand.
The best thing to to do is an inch of foam, and cellulose on the top.

You are correct though, if you use foam and don't have anywhere for in-home humidity to escape, you are going to see sweaty windows.

[Molitoth]

Originally Posted by BucEyedPea

I had a Duke Energy audit here in Florida last Fall and they said cellulose is crap. Bigger savings was with foam.

They are full of shit. =P

[kccrow]

Originally Posted by Molitoth

The professionals use a perfect water mixture to blow cellulose in wet, which activates the stickiness in the paper. This will not settle if done right.

Go to Lowes and rent your own blower and do it yourself? It's going to be messy as hell, and settle badly.



The first Inch of Foam acts as a great vapor barrier. After that, it's not anymore R-value than cellulose from what I understand.
The best thing to to do is an inch of foam, and cellulose on the top.

You are correct though, if you use foam and don't have anywhere for in-home humidity to escape, you are going to see sweaty windows.

This is why new homes get built with an air exchanger.

[Bob Dole]

I need to insulate under the house this summer. (Pier and beam). Is there anything other than old school fiberglass?

[BWillie]

Originally Posted by Dante84

I sell new homes and condos that use spray foam insulation and solar panels.

If done right (thick walls, on the rafters in the attic), your home will act like a cooler.

2000 sq ft home has ~ $20 electric bill... in Austin Tx which is hot as hell.

Someone please help. The two houses that I pay utilities on get to $450 and $410 in July. They are just average 4 and 3 bedroom Johnson County houses 200k - 300k. Its eating me alive. One is 1984 and other is 2001 construction. They must be horribly insulated, only thing I can think of.

Who is good, efficient & cost effective around my parts?

[FlaChief58]

Originally Posted by BWillie

Someone please help. The two houses that I pay utilities on get to $450 and $410 in July. They are just average 4 and 3 bedroom Johnson County houses 200k - 300k. Its eating me alive. One is 1984 and other is 2001 construction. They must be horribly insulated, only thing I can think of.

Who is good, efficient & cost effective around my parts?

Windows, insulation and new energy efficient HVAC may be pricey up front, but will save you $$ in the long run

[kccrow]

Originally Posted by Bob Dole

I need to insulate under the house this summer. (Pier and beam). Is there anything other than old school fiberglass?

You can do whatever method you really want (consult a local builder for humidity/condensation concerns)...

Most do one of these:
1. Batts between the floor joists (vapor barrier against the floor) with OSB sheathing covering it (some use lauan sheets, some use masonite sheets...), seal the joints (some don't cover at all and just use poultry wire...)
2. Sheathing on the joists, blow 2.5 lb - 3.5 lb cellulose into the space you've made between the sheathing and the floor, seal the joints
3. Closed-cell spray foam between the joists, but generally lowest R-Value of the 3 options.

The issue with cellulose can be, once it settles it can create an air gap and that allows condensation to form and your floor could rot. I'm not saying it will, but it's not the option I'd choose.

Here's an article from LSU on hot/humid areas:

http://www.lsuagcenter.com/NR/rdonly...oorsLOWRES.pdf

I will say, some may recommend you don't do anything at all because breathability with that style foundation is a huge plus.

[kccrow]

Originally Posted by BWillie

Someone please help. The two houses that I pay utilities on get to $450 and $410 in July. They are just average 4 and 3 bedroom Johnson County houses 200k - 300k. Its eating me alive. One is 1984 and other is 2001 construction. They must be horribly insulated, only thing I can think of.

Who is good, efficient & cost effective around my parts?

Get a blower door test done. Don't throw money at maybe's.

[Molitoth]

Originally Posted by BWillie

Someone please help. The two houses that I pay utilities on get to $450 and $410 in July. They are just average 4 and 3 bedroom Johnson County houses 200k - 300k. Its eating me alive. One is 1984 and other is 2001 construction. They must be horribly insulated, only thing I can think of.

Who is good, efficient & cost effective around my parts?

Insulation is a major area that builders can cost cut without it being noticeable to the buyer, and rightfully so I suppose because electric bills are not their problem after the house is sold.

[Bob Dole]

Originally Posted by kccrow

You can do whatever method you really want (consult a local builder for humidity/condensation concerns)...

Most do one of these:
1. Batts between the floor joists (vapor barrier against the floor) with OSB sheathing covering it (some use lauan sheets, some use masonite sheets...), seal the joints (some don't cover at all and just use poultry wire...)
2. Sheathing on the joists, blow 2.5 lb - 3.5 lb cellulose into the space you've made between the sheathing and the floor, seal the joints
3. Closed-cell spray foam between the joists, but generally lowest R-Value of the 3 options.

The issue with cellulose can be, once it settles it can create an air gap and that allows condensation to form and your floor could rot. I'm not saying it will, but it's not the option I'd choose.

Here's an article from LSU on hot/humid areas:

http://www.lsuagcenter.com/NR/rdonly...oorsLOWRES.pdf

I will say, some may recommend you don't do anything at all because breathability with that style foundation is a huge plus.

Thanks. I’m using privacy fence board with 1/8” gap for skirting to knock down the wind, so breathing shouldn’t be an issue. I may go with nothing next winter and see how it goes. Last winter was the coldest we’ve had since I moved here, I my 1500w electric heater struggled. The mini-split should be in by next winter.

[markd2000]

I live in Florida and had my attic sprayed with foam and the old insulation removed just over a year ago. I've tracked my electric bills and in the first year my bills averaged 32% less. Pay back will be about 7 years, but my home temperature is much better and the humidity levels have dropped. Humidity is a big deal in Florida.

[kccrow]

Originally Posted by Molitoth

Insulation is a major area that builders can cost cut without it being noticeable to the buyer, and rightfully so I suppose because electric bills are not their problem after the house is sold.

Not necessarily just cost-cut, because they still have to build it to code, but I get what you're saying. They aren't going to go above and beyond code unless you get it in the contract.

[ChiefGator]

Originally Posted by markd2000

I live in Florida and had my attic sprayed with foam and the old insulation removed just over a year ago. I've tracked my electric bills and in the first year my bills averaged 32% less. Pay back will be about 7 years, but my home temperature is much better and the humidity levels have dropped. Humidity is a big deal in Florida.

Thanks.. nice to see some actual numbers...