Spray Foam Insulation

[Grumpycat]

Investigating all options for home I will have built this coming year.

Am favoring ICF construction. Spray foam is an option for the roof.

Have concerns about fire codes. That some spray foam material is not as fireproof as fiberglass wool. That all require another layer to slow the progress of fire. That usually 1/2" gypsum board serves but that doesn't apply to foam sprayed on the underside of the roof.

If you have seen YouTube videos of spray foam being applied you wouldn't dare try to spray foam into a finished wall. Foam expands for seconds after being sprayed so it would have to push up or out. Is most commonly applied between the joists and if you want the void filled then they come back later and shave the excess off.

A very interesting concept for a barndominium, a house built inside a metal building, was to build a 2x4 stud wall a small distance from the metal outer wall then fill that void with spray foam partially into the 2x4 space. Eliminates most of the heat/cooling loss through the wood studs. Eliminates the problem of an uneven foam inner surface. Leaves room between the studs for wiring.

Much the same fire concerns for ICF.

 

[Corkpuller]

How close are you to T Bend?

We are looking for a Builder for a shop and home.

 

[IXLR8]

If you are building, here is something new to consider, insulated 2x6 studs. Wood only has an R value of 1/inch. You may have R19 in the walls, but with 10% of your wall being studs with only an R value of 6, the overall wall R value is about 12. You need to do something to break the thermal bridge that the 2x6 creates. I have no affiliation with this company, I just stumbled upon them a few weeks ago when researching building materials.
Tstud

 

[3Ts]

Investigating all options for home I will have built this coming year.

Am favoring ICF construction. Spray foam is an option for the roof.

Have concerns about fire codes. That some spray foam material is not as fireproof as fiberglass wool. That all require another layer to slow the progress of fire. That usually 1/2" gypsum board serves but that doesn't apply to foam sprayed on the underside of the roof.

If you have seen YouTube videos of spray foam being applied you wouldn't dare try to spray foam into a finished wall. Foam expands for seconds after being sprayed so it would have to push up or out. Is most commonly applied between the joists and if you want the void filled then they come back later and shave the excess off.

A very interesting concept for a barndominium, a house built inside a metal building, was to build a 2x4 stud wall a small distance from the metal outer wall then fill that void with spray foam partially into the 2x4 space. Eliminates most of the heat/cooling loss through the wood studs. Eliminates the problem of an uneven foam inner surface. Leaves room between the studs for wiring.

Much the same fire concerns for ICF.

If you have exposed spray foam and are concerned about fire, look into intumescent paint as a possible solution.
Intumescent Paint, Fireproofing, and Firestopping - archtoolbox.com

 

[EddieWalker]

If you are building, here is something new to consider, insulated 2x6 studs. Wood only has an R value of 1/inch. You may have R19 in the walls, but with 10% of your wall being studs with only an R value of 6, the overall wall R value is about 12. You need to do something to break the thermal bridge that the 2x6 creates. I have no affiliation with this company, I just stumbled upon them a few weeks ago when researching building materials.
Tstud

Insulation is one of those things that it's real easy to get caught up in a lot of little things that wont actually provide any noticeable improvement in a house that can cost a lot of money. Wood studs are not even close to being as big an energy loss as windows and doors. You can spend tens of thousands of dollars more on a house improving your windows and doors, and still not see any savings in your energy bill. What is most important on a wall is stopping air flow. If a decent 2 pane window is taped, and the house is wrapped with all the seams taped, just about any type of wall insulation is going to give the same results. The newest trend is to paint the sheathing with a WRB Paint. Zip System is OSB with a WRB already applied that relies on tape being added to the seams. Stopping the wind is where you gain your noticeable results in the walls.

Heat gain and loss is almost exclusively controlled by how well the attic area, or roof, is insulated. This is where foam really shines. Nothing is better then closed cell foam. I would never use open cell and personally think it should be banned from being used in homes. For less money, blown in insulation will give you the same results if you have it applied deep enough to achieve the same R value. It's all about the R value and how much room you have to obtain it. I have 2 feet of blown in Atticat in my house and it's awesome. When I build my shop, I will have a ceiling so I can do the same in there. When I add on to my house, I will have a vaulted exposed beam ceiling with no room for blown in insulation, so I will use closed cell foam for there.

Those are the basics. You can tweek the basics and obtain some small results, but overall, there isn't very much else that you can do that will provide a noticeable improvement over what you get with a air tight wall and R60 ceiling.

 

[ruffdog]

Is there any issues with foam off-gassing and people breathing the fumes? I'm sure the attic would be ok but don't know about walls. Some people are very susceptible to certain fumes.

Does Spray Foam Insulation Off-Gas Poisonous Fumes? - GreenBuildingAdvisor

Potential Chemical Exposures From Spray Polyurethane Foam | Safer Choice | US EPA

 

[jgedmond]

Insulation is one of those things that it's real easy to get caught up in a lot of little things that wont actually provide any noticeable improvement in a house that can cost a lot of money. Wood studs are not even close to being as big an energy loss as windows and doors. You can spend tens of thousands of dollars more on a house improving your windows and doors, and still not see any savings in your energy bill. What is most important on a wall is stopping air flow. If a decent 2 pane window is taped, and the house is wrapped with all the seams taped, just about any type of wall insulation is going to give the same results. The newest trend is to paint the sheathing with a WRB Paint. Zip System is OSB with a WRB already applied that relies on tape being added to the seams. Stopping the wind is where you gain your noticeable results in the walls.

Heat gain and loss is almost exclusively controlled by how well the attic area, or roof, is insulated. This is where foam really shines. Nothing is better then closed cell foam. I would never use open cell and personally think it should be banned from being used in homes. For less money, blown in insulation will give you the same results if you have it applied deep enough to achieve the same R value. It's all about the R value and how much room you have to obtain it. I have 2 feet of blown in Atticat in my house and it's awesome. When I build my shop, I will have a ceiling so I can do the same in there. When I add on to my house, I will have a vaulted exposed beam ceiling with no room for blown in insulation, so I will use closed cell foam for there.

Those are the basics. You can tweek the basics and obtain some small results, but overall, there isn't very much else that you can do that will provide a noticeable improvement over what you get with a air tight wall and R60 ceiling.

I much prefer my new 85 F attic with foam under the roof to my old 140 F attic with that messy, dusty blown in stuff underfoot. We use our attic for light storage and it is much more comfortable to store or retrieve something, reset the router, work on A/C etc.

 

[EddieWalker]

I've read some interesting articles on the advantage of doing the full house envelope with spray foam compared to traditional insulation in the attic area. One of the big advantages are not having any roof vents which makes a huge difference in areas that are prone to fire. It does create more area to condition, which means a bigger HVAC system and more money to run the bigger unit, but that's probably not as big as expense as the cost of the spray foam and how long it takes to make up that difference when comparing it to R60 of something like AttiCat blown in insulation.

To deal with higher temps in the attic, I make sure nothing is installed in the attic. HVAC is in a closet that anybody can get to 24/7 no matter how old they are. Same thing with storage. It goes into a shed, barn, shipping container or some other building that is accessable 24/7 by anybody of any age. I've made a lot of money fixing damage to homes from storing stuff in an attic that was more weight then the rafters where able to support.

AttiCat isn't dusty. In fact, it's so nice to work with that you don't even need a mask when spraying it!!!

 

[jgedmond]

I've read some interesting articles on the advantage of doing the full house envelope with spray foam compared to traditional insulation in the attic area. One of the big advantages are not having any roof vents which makes a huge difference in areas that are prone to fire. It does create more area to condition, which means a bigger HVAC system and more money to run the bigger unit, but that's probably not as big as expense as the cost of the spray foam and how long it takes to make up that difference when comparing it to R60 of something like AttiCat blown in insulation.

To deal with higher temps in the attic, I make sure nothing is installed in the attic. HVAC is in a closet that anybody can get to 24/7 no matter how old they are. Same thing with storage. It goes into a shed, barn, shipping container or some other building that is accessable 24/7 by anybody of any age. I've made a lot of money fixing damage to homes from storing stuff in an attic that was more weight then the rafters where able to support.

AttiCat isn't dusty. In fact, it's so nice to work with that you don't even need a mask when spraying it!!!

I am not sure if you have basements in Tyler, but if not, you have stuff in your attic that might need attention at some point (electrical, plumbing, gas lines, vent fan piping, etc) or you may need to access the attic to make improvements / repairs to ceiling mounted fixtures. So, I do not think that staying out of the attic is a viable way to "deal with attic temperatures" although it will minimize your exposure to the hot attic.

The Attic Cat site shows the installers wearing masks, I know that might be CYA, but still it is apparently recommended. My concern was with fibers pieces floating around in the attic air after installation when I may be in the attic.

As to size of the HVAC unit, my new home is 10% more square feet with average taller ceilings and larger attic volume (steeper average roof pitch). With the same size HVAC unit, run times and costs are much lower despite cooling that larger volume of air to a lower temperature.

Roof decking moisture issues seem to relate to how well the attic is sealed from external moisture intrusion (did the installers do a good job identifying and covering the house envelope) and having sufficient attic air humidity control (attic supply and return if codes allow).

Think that I am going to put a humidity monitor in my attic to keep an eye on that.

Will Open-Cell Spray Foam Insulation Really Rot Your Roof?

 

[JamesHW]

We entertained spray foam for the uninsulated attic(s) on our 150 year old house and it’s 1920’s addition (built onto an original bump out in the back). As I have developed a fairly serious chemical sensitivity we have remained reticent in pulling the trigger. Speaking with a couple of experienced installers they told me the horror stories of improperly cured foam off gassing an odor long after drying were a result of either temps out of optimum range, either too hot or cold and/or improperly mixed ingredients of the foam. So going with a reputable installer is important. Once installed, removing a botched job would be a nightmare and could chance rendering our home unlivable, at least for me.

Then we remembered being pitched SIP panels for a barn build we were planning and realized these structural panels would be perfect installed over the original roof. Concern over it creating a too thick roof, we remembered that when we reattached some steel roofing that needed securing we found thousands of cut nails sticking up from the roof boards that indicated the roof originally had wood shake shingles that undoubtedly would have presented a much thicker profile than the corrugated roof panels have, alleviating any concerns over esthetics. Because the panels are made under controlled conditions in a factory. So the structural panels give us the insulating properties of closed cell foam w/o any of the possible off-gassing hazards, at least for our roof. I like the Ray-Core panels