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?

[kccrow]

Company I work for builds modular homes (not the same as manufactured/mobile)... We rarely use spray foam in any application. Usually build with 12" energy heel trusses and R-39 in the attic. If you don't have energy heels, just make sure the ends are as well insulated as you can get them.

You're talking about the roof, but you probably don't know the exact condition of your walls either. I'd highly recommend first getting a blower door test done to see where you are leaking.

I'd use the test results and focus on a better envelope by getting proper exterior air tightness/sealing.

Once you know you're airtight, then you can focus your efforts. You may find you need to add rigid insulation to the exterior walls as well.

If you are looking to have a well insulated home, you should install a good air exchange system with a heat recovery ventilator, etc because not only will it improve the air quality, it will help with heating and cooling costs.

If you do insist on spray foam, it can be better provided those steps are performed above. I say "can be," because spray foam installers don't always fill every crevice either and an air gap is an air gap. You have to be well-sealed one way or the other.

You'll probably spend 3-4 times as much on the insulation, but ROI in modern applications is much better at around 5 years. If there were any place I'd absolutely consider spray foam personally, it is in the attic.

[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.

[Dunit35]

I just had 8” of insulation added in our attic last week. 2100sq ft home cost us $1250. It wasn’t spray foam though. It’s some kind of cotton candy type material.

[MTG#10]

I just had 8” of insulation added in our attic last week. 2100sq ft home cost us $1250. It wasn’t spray foam though. It’s some kind of cotton candy type material.

My house is close to yours, a little over 2300 sq ft. If you'd be willing I'd love to hear how much (if any) you notice in your utility bill the next couple months.

[ThaVirus]

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.


Tell me more..

I wonder if that application would have the same effect in a more humid environment, say Florida?

[kccrow]

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.

50% of doing it right has absolutely nothing to do with the insulation itself and much more to do with the prep in proper sealing. You get the benefit, like me, of having a new home to work with where everything can be sealed, checked, sealed in missed areas, then sprayd. He isn't getting that benefit in an old home just by spraying some foam upstairs, but he can get closer if he takes the proper steps.

[RealSNR]

Just use asbestos.

[Perineum Ripper]

Just use asbestos.

Don’t forget to top it off with fine lead based paints

[Pablo]

Just use asbestos.

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.

[BryanBusby]

Just use asbestos.
Make sure to coat it with antifreeze first, so it doesn't freeze and lose its power in the winter.

[SAUTO]

Don’t forget to top it off with fine lead based paints

And apply with tongue

[SAUTO]

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.

Yuck

[Perineum Ripper]

And apply with tongue

The best and only method I would recommend

[Dunit35]

My house is close to yours, a little over 2300 sq ft. If you'd be willing I'd love to hear how much (if any) you notice in your utility bill the next couple months.

It had 2” of old insulation in it when we bought it. Unfortunately, we have only been in this house since April 1st so won’t be able to compare previous months.

[Iowanian]

You might look into the solar radiant attIc blanket. I think that's what it's called. Roll that on top of your existing insulation.

[BlackHelicopters]

Bodies of dead immigrants work well as insulation when sealed properly.

[ptlyon]

It had 2” of old insulation in it when we bought it. Unfortunately, we have only been in this house since April 1st so won’t be able to compare previous months.

You can get that information from your electric company. What you won't know however is how they kept their thermostat as a comparison.

[ptlyon]

Bodies of dead immigrants work well as insulation when sealed properly.

I've owned my house for 20 years and have never been in the attic, and never will, God willing. It was built in 1954.

I've always said there could be treasure chests of gold bouillon up there or dead bodies. I don't want to know.

[Dunit35]

You can get that information from your electric company. What you won't know however is how they kept their thermostat as a comparison.

The house sat vacant for two years so I’m sure it’s all jacked up.

Installer did say I’d save a few dollars a month but nothing drastic.

[ptlyon]

The house sat vacant for two years so I’m sure it’s all jacked up.



Sorry missed that part

[srvy]

My house I bought in 87 was built in 1956. Several seasons of trying to heat and cool the the outside I had foam insulation blown in the walls and corning glass in the attic. I thought it made a huge difference. In 2010 I replaced the original old Coleman furnace that wouldnt die along with a old Bryant central air unit that did. Made even more of a difference as they barely cycle on and off during hottest summer and coldest winters.

[mikeyis4dcats.]

no. Just add more blown in or batt on top of what you have. Even that may not be that cost effective in energy savings, but it will help.

[mikeyis4dcats.]

You might look into the solar radiant attIc blanket. I think that's what it's called. Roll that on top of your existing insulation.


radiant barrier is typically meant to be installed beneath the sheathing ror between the rafters. The idea is to keep the attic space cooler.

[srvy]

I failed to mention stay on top of caulking window seals and panes and make sure door sweeps are functioning as should. Also caulk storm windows and be sure they are in good condition. You will be surprised how well it works with good insulation.

[Molitoth]

Foam is great but expensive. Look into Cellulose insulation in your attic and walls.
I've had cellulose in both of my homes and each job has paid itself off in energy savings within 3 years. If you are building a new home for yourself, or plan on being in a home over 5 years, it is worth the investment.

Bonus: The Sound isolation is also great.

If you are interested in the St. Joseph or KC Northland:
http://brandtsfuelsavers.com/insulation/4710456

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[BucEyedPea]

I just had 8” of insulation added in our attic last week. 2100sq ft home cost us $1250. It wasn’t spray foam though. It’s some kind of cotton candy type material.

Yummy! Can you eat it too?

[BucEyedPea]

Foam is great but expensive.
You want a much more efficient product than shitty Fiberglass? Look into Cellulose insulation in your attic and walls.
I've had cellulose in both of my homes and each job has paid itself off in energy savings within 3 years. If you are building a new home for yourself, or plan on being in a home over 5 years, it is worth the investment.

Bonus: The Sound isolation is also great.

If you are interested in the St. Joseph or KC Northland:
http://brandtsfuelsavers.com/insulation/4710456



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

[nagami]

subscribed, this seems like a very interesting thread

[Molitoth]

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

It all depends on budget.

If money is not an issue, spray foam your whole house.

If you want great efficiency without breaking the bank. Cellulose.

If you don't care about your home efficiency, or live in San Diego type weather. Fiberglass it up.

[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]

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.

ROFL

[Molitoth]

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]

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]

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]

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]

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]

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/rdonlyres/D33F711D-DC4B-4E4C-9ED6-A97DCE9DB026/79805/pub3187insulatingraisedfloorsLOWRES.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]

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]

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]

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/rdonlyres/D33F711D-DC4B-4E4C-9ED6-A97DCE9DB026/79805/pub3187insulatingraisedfloorsLOWRES.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]

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]

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...