Down side to spray foam??

[Kels]

So I might go with spray foam in my metal pole building.

However I am thinking their might be some down sides if I did this.
The big one I can think of is if I need to change windows or a metal panel in the future I would not be able to...

Is there a work around for this or no?

Basically I have aluminum framed windows in the shop, They are double pane and seem to be in good condition so am not sure if it is worth it to switch them to vinyl. If I did this it would be to decrease condensation issues (Is it really worth it for 3 windows?). I might make one of them larger if I did that but am not sure where to get matching components and would want all the windows to match.

Is switching from Alum to Vinyl windows worth it?

Will CC SPF make this job silly difficult in the future?

Will CC SPF make other jobs I have not thought of yet impossible or way to hard?

 

[BoostAddiction]

I really like spray foam for insulation, as it does an effective job of sealing as well as providing a generally higher level of insulation per inch.

However, it is much more expensive, and proper application is critical. There have been cases where the ratio of A to B agents were not right, and the foam had to be completely removed from the home- not a good result.

If I were building another house, I would give real thought to it, possibly as a "flash and fill" approach, which involves using a thin covering of foam for good sealing, followed by more traditional, and less expensive insulation like dense-pack cellulose (which my current home has) or Fiberglass to get to the desired R-value

You can change windows later, you just need to scrape out the old foam, and re-apply it for a good seal. Some installers use the spray foam in a can for sealing around windows, etc., when doing renos.

 

[theoldwizard1]

To answer the OP's question, the most common complaint about spray foam is the building is "too tight" and odors do not migrate out and little or no fresh air gets in.

I really like spray foam for insulation, as it does an effective job of sealing as well as providing a generally higher level of insulation per inch.

A friend of a friend is a certified energy auditor. He says that spray foam is the best you can get.

However, it is much more expensive, and proper application is critical.

He would agree with both of those statements, especially the first one.

If I were building another house, I would give real thought to it, possibly as a "flash and fill" approach, which involves using a thin covering of foam for good sealing, followed by more traditional, and less expensive insulation like dense-pack cellulose (which my current home has) or Fiberglass to get to the desired R-value

Never heard of "flash and fill", but I'm sure my buddy would recommend it for the reasons you just mentioned, especially for "stick built" structures with traditional 2x4 or 2x6 construction.

While foam may be "the best", "wet" cellulose is probably the most cost effective. Fast, all most zero waste, possible DIY.

I have no idea how it would work with a metal pole building because the outer sheathing and the inner vapor barrier and drywall hold the cellulose in place.

 

[Fyrme]

Something else to consider is unprotected spray foam it HIGHLY flammable and will burn your building to the ground with in minutes. If you do spray it in you need to cover it with Sheetrock or a fire retardant coating. I personally have witnessed the testing on this stuff and, being in the fire service, I don't think I'll ever use it in one of my properties.

 

[JakeKohl]

Something else to consider is unprotected spray foam it HIGHLY flammable and will burn your building to the ground with in minutes. If you do spray it in you need to cover it with Sheetrock or a fire retardant coating. I personally have witnessed the testing on this stuff and, being in the fire service, I don't think I'll ever use it in one of my properties.

the last time I had spray foam quoted (a couple of years ago), the local code/ordinance had changed and they had to use a fire resistant foam that caused the price to go up dramatically. $11k to insulate a two story 24x36 (no interior walls) with foam. So, I might point out, one downside is cost.

 

[bullnerd]

Talk to someone who has used it in a metal building!

A friend on another forum wanted to use it and the foam contractor said it would buckle the metal on the outside.He ended up using OSB and vinyl siding.

 

[fflintstone]

the only REAL downside is cost. A "tight" building can be ventilated cheaply.

 

[fire1068]

A local fellow voided his warranty on his steel building since the foam was applied directly to the steel and panels could not be changed. They stated that if he had put a layer of rigid foam on first then spray foamed everything it would have been fine.Just something to ask..

 

[Daniel Dudley]

You need to use closed cell in a metal building. I tore out the fiberglass in my attic this spring and had open cell shot on the rafters. The difference in the temperature of my second floor rooms is dramatic.

Yes, I paid extra for the fire coating.

 

[cyamaha2007]

Cost. Your planing on covering it anyway from your previous thread. The foam we use had a fire block built in. The building will be very tight so smells will stick around without venting. You just have to get a contractor that has done this before. Removing a panel isnt a big deal. Just score the foam with a knife remove panel and replace it with new. They make kits that are diy for small applications just like this so you would just spray the new panel and feather it in kinda like stucco. If the buildings metal is in good shape I cant think of a need to replace a panel. Ive removed them after spray foam to add on and the foam bonded so well i just left it on the panel when we reinstalled. I just had to touch up the seams.

 

[Kels]

Cost. Your planing on covering it anyway from your previous thread. The foam we use had a fire block built in. The building will be very tight so smells will stick around without venting. You just have to get a contractor that has done this before. Removing a panel isnt a big deal. Just score the foam with a knife remove panel and replace it with new. They make kits that are diy for small applications just like this so you would just spray the new panel and feather it in kinda like stucco. If the buildings metal is in good shape I cant think of a need to replace a panel. Ive removed them after spray foam to add on and the foam bonded so well i just left it on the panel when we reinstalled. I just had to touch up the seams.

Thank you! This is what I wanted to know was not sure if anyone had replaced a panel once it was foamed...not that I see a need to but you never know if you might.

Any info on the venting? none of the Contractors that have talked to me mentioned venting.

I could see if I was doing any oil painting venting would be nice.

I read about people that have had the metal distorted from the spray foam, is this caused by poor application or bad temperatures during application?

 

[cyamaha2007]

Thank you! This is what I wanted to know was not sure if anyone had replaced a panel once it was foamed...not that I see a need to but you never know if you might.

Any info on the venting? none of the Contractors that have talked to me mentioned venting.

A wall mounted power vent/ exhaust fan is your best option, a small model would go along way for what your doing. Keep in mind that you will need a window or door open when the fan is on. If you dont allow fresh air in the building will go into a slight vacuum its enough that my garage doors **** in 3in or so if i forget to open a window. If you dont want to open a window you can install fresh air intake ducts that you open during the fans operation.
I could see if I was doing any oil painting venting would be nice.

I read about people that have had the metal distorted from the spray foam, is this caused by poor application or bad temperatures during application?

My good friend owns a spray foam company. I asked him on this and he said its caused by using the wrong expansion rate foam. If the foam expands too much for the void its filling it has to go somewhere .

My good friend owns a spray foam company. I asked him on this and he said its caused by using the wrong expansion rate foam. If the foam expands too much for the void its filling it has to go somewhere .

 

[lt1driver]

would spray foam add any strength to the siding from wind etc.???

 

[theoldwizard1]

would spray foam add any strength to the siding from wind etc.???

Some. Depends on how thick it is applied.

 

[Glammers37]

My buddy talked me into spray foam insulation for my 36x50 shop back in 1991. I sprayed 1-1/2" on then 5-1/2" fiberglass bats. Wow! even here in MN IN -20 degrees you could heat this shop with a hair dryer! I would never think of building a new building without spray foaming it. I rebuilt a 5th wheel trailer two yrs ago, and spray foamed it, quiet, warm\cool, plus it helps structural strength. The only problem is it is so tight, you almost need some sort of air exchange. I usually run a dehumidifier in the summer, and keep it closed up.

 

[cyamaha2007]

My buddy talked me into spray foam insulation for my 36x50 shop back in 1991. I sprayed 1-1/2" on then 5-1/2" fiberglass bats. Wow! even here in MN IN -20 degrees you could heat this shop with a hair dryer! I would never think of building a new building without spray foaming it. I rebuilt a 5th wheel trailer two yrs ago, and spray foamed it, quiet, warm\cool, plus it helps structural strength. The only problem is it is so tight, you almost need some sort of air exchange. I usually run a dehumidifier in the summer, and keep it closed up.

Yep a fart from 5hrs ago will still run you out. But really thats great since unconditioned air isnt leaking into conditioned space.

 

[RTcat]

Kels,

On my 32 x 50 shop I went the following route from the outside in:

Tin
ty-vek
5/8 osb
sprayfoam to ~R25 value
1/2 drywall
paint

Ceiling looking up is:

Paint
5/8 drywall
bisqueen (plastic)
24" blown cellouse

I can heat the place with a candle.

Enjoy your build!

 

[Dennis93]

Spray foam is the BEST. Just do all your rough construction, electrical, plumbing, and all before and cover everything you don't want foam it. It will travel farther than spray paint.

It
1. adds structural rigidity
2. takes a building envelope and completely throws it out the window by making everything a conditioned space.
3. Adds a vapor barrier.
4. Takes less space than conventional insulation.
5. You can say it only has an r3-6 per inch. BUT an inch of spray foam would do you more good than 12 inches of fiberglass.
6. Speaking from experience, my attic has never been above 85 degrees. Even in the heat of summer, with 2 inches of spray foam. My attic fan before with 8 inches of blown in cellulose it was running almost the whole day set at 115. BTW, I closed up the attic fan with a plastic cover instead of letting them spray over it. That way if I ever need fresh air up there I can just open the bottom, and let the attic fan run to get some air through the attic.
7. If you go by those retards at the EPA and their tests, they claim you need like 6 or so inches of spray foam to get like r32 (I know some of the codes in the northern states require that much, here's it r19. Those studies aren't worth a damn, almost like how fuel economy numbers weren't worth a damn ~2 years ago before they revised their standards.
8. You can absolutely change anything, just takes a lot more work. But remember, if you ever need to like for example resheath your roof, you're better of doing that first and then spray foaming or else you're throwing your money down the drain. So make sure everything it's getting attached to doesn't need to be replaced.
9. Less strain on your HVAC, lasts longer.
10. Great sound barrier.

I ABSOLUTELY LOVE spray foam but since every time anyone asks for recommendations they only get the good from one guy I'll give you the negatives.

1. Price, but oh will you save some money in the long run. I wouldn't do this unless I was staying there atleast 10 years.
2. Some of those liberals want to complain about fumes and what not and there's rumors the fumes are bad for pregnant ladies. But you're an idiot if you keep a pregnant woman exposed to **** she shouldn't be. I'm sure it's almost illegal in CA which makes me want to buy it. *I read not allowed in state of CA as an advantage* Generally means its worse for the environment but will do it's job well and cheaply.
3. It goes up in flames fast, but I think some people forget that almost all of us live in wood frame houses. If you're house is on fire, it's on fire. Let the insurance cover it, that's their job anyway. I'm not saying don't practice safety or have a fire extinguisher, but choosing things based on their fire retarding capability? Not my thing...

Couple things.
When I was doing my bathroom, I used one of those DIY kits, works fine and is cheaper than having the guys come out for just a little job. I wouldn't recommend it for an entire attic or something, but you have to figure someone charges you X amount just to show up and get their equipment dirty and clean it. For small jobs it makes sense to do it that way.

Make sure you get CLOSED cell. Some guys will tell you to go open cell, but it takes more room for the same r value and doesn't provide a vapor barrier. It's almost only used in situations where you need superior sound damping and thickness isn't an issue. It is cheaper but takes so much more room.

 

[Dennis93]

Just read the venting part.

You NEVER vent anything when spray foaming it. Matter of fact, their close up your soffits and ridge vents and spray it closed because everything becomes conditioned space. If you add like an attic fan and run it you are just defeating the purpose of having spray foam. Now if you want to vent it by opening a window or something to actually vent the room or garage like for odors or fresh air, that's different.

 

[justanengineer]

I think the biggest downside is the flammability of it. You can do a lot to block it, but fire will usually find a way. When I lived back east the local FD was very good at spotting it (along with cabinets of flammables, dont ask how I know), and once they did they usually retreated and mostly let it burn itself out. Beyond that, the cost is rather ridiculous IMHO, and it also does a very good job of holding moisture which is already a concern in a steel building. Personally, Id look at other options.

 

[cyamaha2007]

I think the biggest downside is the flammability of it. You can do a lot to block it, but fire will usually find a way. When I lived back east the local FD was very good at spotting it (along with cabinets of flammables, dont ask how I know), and once they did they usually retreated and mostly let it burn itself out. Beyond that, the cost is rather ridiculous IMHO, and it also does a very good job of holding moisture which is already a concern in a steel building. Personally, Id look at other options.

I have no idea what you mean by holds moisture very good. Spray foam eliminates a steel buildings condensation issue totally. So unless she has a plan to flood the building with water I dont see the issue. No mater what insulation type if your getting the insulation wet behind finished drywall you have issues.

 

[Kels]

If I go with 2" of CC spf on the walls then fiberglass (flash and bat) then drywall (air sealed). should that work?

I was not planning on doing wiring first I have ~7 or 8 inches of wall space since it was previously studded out... Is this a mistake? Also toying with the idea of having the wiring on the outside of the wall not convinced on this yet.

The roof has the steel building condensation blanket on it and in good condition just needs a few pieces of tape. I was going to ad Fiberglass insulation to the rafters/purlins they are 2x8, if I remember correctly. Then 6 mil poly and Sheetrock. Will this work with doing the walls flash and bat. This would be built as a hot roof, Don't want to loose the cathedral ceiling in that room would make it very cramped.

This way the roof could be changed in the future and it would save some cash.

 

[Dennis93]

If you do 2 in of CC, you won't need anything else. At the very least don't buy the material and see how the foam does by itself. Just do your roof with the batt and see how the building changes.

 

[justanengineer]

I have no idea what you mean by holds moisture very good. Spray foam eliminates a steel buildings condensation issue totally.

Sorry, I meant humidity, not condensation. Youre correct, keep the hot tin away from the humidity and you wont get the condensation as in uninsulated buildings. Maybe Im just sensitive, but steel buildings always just seemed too "tight" to me compared to wood construction.

 

[86turbodsl]

I have a 3000 sq ft house with 2" closed cell in the walls and in the attic and I heat my house with a 3 ton heat pump in michigan. Try that with fiberglass.

 

[Addrock]

The downside not yet mentioned is spray foam loses R-value.

 

[Kels]

So does anyone see a problem with using CC Spray foam on the walls and not the ceiling.

The ceiling has the standard condensation blanket on it and is in good shape. I would be adding Fiberglass rolls to the ceiling to increase the R-value, vapor barrier then sheet rock.

The ceiling would NOT be ventilated! it is not currently vented.
__________________________________________________________

The walls would have 2" CC then either filled with fiberglass and dry-walled or just drywalled.

(Can I have an 4 inch air gap between drywall and Spray foam in the wall and not fill it?)

 

[matouse3]

The downside not yet mentioned is spray foam loses R-value.

Where exactly did you get this information? Please supply a link or something to this claim.

Are you just talking about the initial loss of Rvalue after installation from approximately R10 per inch to approx. R6.5 per inch? The work that I've read shows that it stabilizes there for decades.

 

[dirttracker18]

Where exactly did you get this information? Please supply a link or something to this claim.

Are you just talking about the initial lose of Rvalue after installation from approximately R10 per inch to approx. R6.5 per inch? The work that I've read shows that it stabilizes there for decades.

Same

Count me in as another proponent for spray foam.

However in all the research I did before using it I never heard of it losing R value.

 

[Sureshot]

I asked a Morton sales rep about spray foam on Monday and he said you didn't want to put it on the metal because of the hot/cold cycling causing it to crack away and release. First I have heard of it. He said you need to put felt paper or something between the foam and tin. Seems odd to me.

 

[Camper]

The metal siding on the warehouse I work in was replaced a few years ago followed by spray foam insulation right on the metal.....been about 5 yrs now with no problems.
Building sure is a lot more comfortable than it used to be.