Insulating Metal Building

I have an existing metal building I'd like to insulate and need some suggestions. Thanks.

One of the problems in insulating metal buildings is air sealing the interior metal from moisture in the air. I've been in (uninsulated) metal buildings that have virtually rained inside. Improper insulation installation lets humid air get through to the cold plane (the metal) and condense there, running down into or bidden by the insulation.

There are batt type insulations with a vinyl facing similar to the kraft paper used on conventional fiberglass batts.  Like these...
http://www.steelbuildinginsulation.com/Insulation%20Options/InsulationOptions.html
Those batts have overlaps with self adhesive strips. Strapping is used to hold them up. Some places do not permit their use without being faced over with a fire resistant material.

A very efficient method is spray on, mixed at delivery foam. Some are more environmentally friendly than others. All are at the top of the price range. They are sprayed in place and insulate and seal at one time. Mostly it's the realm of the professional installer. There are some home spray kits available. One member of our forum is in the process of planning a doityourself spray foam installation. The system he chose requires a large capacity air compressor and that is where he's temporarily halted right now.



The important thing is to keep the interior moisture from getting through to the cold metal. Spray foam is superb at that.

I'm not sure what kind of condensation (or space) you are dealing with. The amount of water that Don described sounds like it occurred through condensation, which wouldn't be such a problem if the building is sealed and insulated. If it's anything like Don described, this won't work, but the first thing that popped into my head was Strawbale with an interior natural plaster. Depending on your climate, you could cut the bale down the middle. Half a bales width would be sufficient insulation here in Oregon, and take less space away from you.

We have metal buildings also and condensation is a problem where they are uninsulated.  I highly suggest the spray foam.  I called around and the rates do vary quite a bit.  Also there are both high density and low density foams, so do your research, but the spray on seems infinity better suited for the buildings because it adheres to the metal thus not providing any space for condensation like bats will, there will always be some area where there is a little gap with bats.

Only draw back to spray on foam is cost and the foam must be covered with a fire barrier. Other than those foam is the best bank for your buck .....

Spray foam might be the easiest method but it is definately not the most environmentaly friendly. Spray foams:
- All rely on petro-chemicals in their production (even so-called soy or bio-based products)
- They are extremely toxic to your health during application
- When cured they form a non-recyclable plastic
- If you ever need to remove the stuff for a renovation you'll have a VERY hard time removing it (especially if it's been sprayed over wiring or plumbing)
- If part of your goal is energy-conservation, the embodied energy (the amount of energy used to manufacture the product) is so high that it is possible that you will never save enough energy using it to even offset the energy used during it's manufacture.
- Last but not least spray foam is expensive.

I'd say your options mostly depend on exactly how your metal structure is built but most commercial/industrial metal buildings constructed in cold climates these days will use an "outsualtion"  approach to insulation, meaning that the insulation is all to the exterior of the wall then siding over that. If done correctly, this approach has the big advantage of elimainating most all thermal bridging which is especially significant in steel buildings. Any rigid board-type insulation will do for this approach but I personally try to using avoid foam boards whenever possible.

If you have any links or sources on the soy/ eco foams and their problems I 'd be interested.  Here we are actually insulating against heat rather than cold.  The estimates I've gotten from contractors are making the foam not that much higher than batts and because the building is arched and metal it requires some sort of alternate fastening system that adds to the cost. Plus the foams have much higher R values, plus seal air gaps.  THe toxicity is a major concern, with any building product.  It is extra tough being in an area that dosen't get much alternative anything, and even insulating isn't all that common.

Whether or not spray foam insulation is the best product for your application is hard to say. I would say that using it is probably better than not insulating at all then blasting the A/C to stay cool. That being said, there is almost always some alternative strategy that can be used to do the same job. Whithout knowing the specifics though it is impossible to say what the best alternative strategy would be. The important thing is to make the most informed decision you can. Buying insulation seems like it should be a simple thing but  unfortunately, like most other things, it's not.

Unfortunately there is very little in the way of independant or unbiased evaluations of the various spray foam products that are available on the market. The vast majority of information that is available comes from the spray foam industry itself and is mostly maketing info. Also, many foam manufacturers have proprietary (secret) fire-retardant recipes for the polyol portion of the foam that may be toxic before, during and after installation. Specific concerns depend on exactly what type of foam you choose (the two main varieties being either open or closed cell foam).

Here is some reading on the subject to get you started. From the commentary following the articles you will see what kind of debate exists over the use of these insulation products:

http://www.greenbuildingadvisor.com/blogs/dept/energy-solutions/avoiding-global-warming-impact-insulation

http://www.greenbuildingadvisor.com/blogs/dept/green-building-blog/does-spray-foam-insulation-out-gas-poisonous-fumes

To answer to too hot a building may be a bit more lowtech than what you are looking at. If you can open up some vent holes (covered in weldwire) at the bottom on the north (or less optimally east) side of the building and along the top (even better would be a cupola) you can take advantage of the stack effect to move the hot air up and out and replace it with slightly less hot air. Furthermore if you could dig a large pond on the side that the vents open up to you could cool the air down a bit before it enters the garage.

The building is being oriented to maximize prevailing winds,  and there is even a pond on that side although during the hottest part of the year it is so very humid adding more moisture to the air makes things worse.  THe pond is a necessity for water storage , and drainage during rainy season.
One of the more challenging aspects of my situation is being in the tropics,  most of the country and folks in the forums are from more 'normal' areas, I'm a transplant to here myself.
THe building is going to be a house not a garage.  My DD and Hubby have the same building and because of the curve and the cost insulated it only on the straight parts leaving the top un insulated, and have a big attic fan at the top to suck the air through the building.  It gets way to hot inside (90+) and the ac dosen't cut it.  none of us are really into ac anyway so it gets set 82 or so and even an oversized unit for the space dosen't get close, so insulation is a MUST.  Like the rest of the world weather pattern changes here are causing unusual temps and we have been 10-20 degrees above normal for most of the year,  translating into heat in the 100+ deg range with high humidity too. 
Vermin, including voracious termites of several varieties, mean steel and concrete, stone IF we had any.  YEs high embodied energy but when I think of replacing the exact same wall from the siding to the sheetrock every 2 years the consumed energy picture changes. Since I am super allergic to the world, except for tropical environments, with ocean breezes this is what I need to make work.
I am concerned about toxicity of the foams, especially since the plan was to spray the foam then plaster over it. Trying to curve sheetrock would be an insane amount of work, so spray on seems the most logical.  Not much is straight forward in this process.
I had been aware of the exterior insulators, but wonder how well it would adhere to galvilume, under heavy winds,  had also been considering cobbing the exterior but again concerned about wind damage and also possibly rust (although the building is warrantied for 30 years against rust) not sure how it would respond to torrential rain, or a hurricane since it would be more in the 4-6" thick range.  I know it isn't an insulator though,  anyone ever mix it with something like perilite like the 'insulating' concrete?
I do appreciate the responses,  it does help me to keep thinking through the options.

Polyurethane is also used as a glue (a different mix though) so it will stick unless the paint is ablative, the sun will eat it though. Depending on how tropical it is maybe you have to give up, big windows letting in tropical sun into a well insulated space can make a giant solar oven.

Yup No big windows, a couple of north facing skylights and the other windows will open into a screened porch area, one on each end of the building, to prevent any direct sunlight.  Plus in addition to maximizing prevailing winds, there are plenty of shade trees especially along the south and west.

Thanks 

Serenity;

Here's what you do.  First, if you don't have any paint on your building, start by prepping your metal, putting on primer, and painting the outside (including the roof) with a latex paint.  I'm saying latex because two coats of latex constitute a vapor barrier.  Use a white paint, then see how well that affects the temperature.

Then, if you feel the need for more thermal protection, cover the outside with "Structural Lightweight Insulated Cob".  That's cob that has 30% pumice.  It is lighter, stronger, and has greater insulation value than regular cob (app. R = 1 for 1 inch compared to R = 0.5 for 1 inch).  The latex paint should protect the metal from any moisture in the cob.  After the cob has dried thoroughly, cover it with lime (NOT CEMENT) plaster.

Or you can just hang a bloomin' big piece of aluminum foil over the whole house (shiny side up) and tell people it's the only way you can get decent cellphone service while keeping the aliens from tapping into your phone lines and making long distance phone calls home.

http://www.islandnet.com/~anngord/builders.html for info on SLIC...

Muzhik,

Thanks for the excellent link to the cob site.  That is a new one for me.  Actually the galvalum looks like aluminum foil already   but the part about cell phone service is close to the truth

Why Lime plaster vs cement?  Embodied energy or something else?  It is super alkaline here so I have a bit of concerns of adding more and It does degrade I would think.  Any ideas on pumice sources?  I have found it challenging to source a lot of things way down here that were common elsewhere.  I so wish manganese/ magnesium (forget exactly)  was more affordable, the water barrier aspect is very appropriate here, and I may opt for it in any case, they do make a stucco but the height and shape will make troweling a bit of a challenge in any case.  Spray on finishes are way easier.

Serenity, simply put, lime plaster breaths; cement plaster doesn't.  If you're concerned about moisture destroying the metal in your structure, you need to have something that will let any moisture out.

As for pumice, if your local building suppliers don't have it or can't get it, then you'll have to go with plain old cob.  If you live in a region that has had any volcanic activity at all in the last hundred thousand years or so, I'd be surprised if it weren't available.

Those who have seen my posts before have already heard this tune, but..

If you live near a rice growing area "earthbag" using rice hulls instead of the earth, then rendered with lime or earth plaster.

That's something for a rice processing area, not necessarily every rice growing area, but a good idea I think. Have to keep it fairly dry?

Emerson White wrote:
That's something for a rice processing area, not necessarily every rice growing area, but a good idea I think. Have to keep it fairly dry?

Yes and no.
Insulative properties rely on the material being dry so yes..
but not as much as you are probably thinking for their structural integrity.
Rice husks are mostly Silica, so they're almost rocks chemically speaking, There are piles of rice husks around where I live that have been exposed to the elements for literally years (and we get enormous amounts of rain, snow and humidity) and the top couple of centimetres have gone grey, but under that the colour and structure of the hulls remains essentially the same.
Very different from straw.

I was thinking of mold living off the rice husks in the still air cavity inside the wall and turning the structure into a big party cracker filled with highly carcinogenic aflatoxins. But I do tend to be a worrier.

Emerson White wrote:
I was thinking of mold living off the rice husks in the still air cavity inside the wall and turning the structure into a big party cracker filled with highly carcinogenic aflatoxins. But I do tend to be a worrier.

Aflatoxin party crackers, I'm sure they'd really liven up a lackluster Christmas dinner.
Rice hulls have passed 28 day fungal growth resistance tests to out perform the southern yellow pine used as a control, and the chemical composition of the hulls and their tendency not to break down provides a long term stability rare in natural insulating materials.
Not perfect, but not too shabby I'd say.

different people face different problems while dealing with metal buildings. so if Miller is facing this, than it may not be happen with everyone else.

I went with Soy Lock Spray foam for my metal building and am very happy with the outcome.  It is a closed cell foam and thus provides a moisture and vapor barrier.  Not only is the bui8lding metal but I choose to use steel studs to frame in all of the rooms the only wood will be decorative.  I also went with a fiber cement siding a bit of a pain to cut but again, living in a sub tropical environment termites of every variety are a major problem as is moisture, rot, rodents, and a whole variety of vermin.    I've found the foam reasonably easy to remove where I needed to, scrapes of the metal and once the surface is broken a wire brush works amazing.  I have chosen to do the spray in 2 stages, so that it was easier for the foam to cover the main structure then finishing the framing and siding plumbing, wiring etc and doing the second inch.  All of the plastic caulking  tubes that can't be recycled are driving me crazy though.  I am going to split some and see if I can use them over the wires that are exposed to keep the foam from them, we shall see, but finding a way to reuse them is high on my list.

With only 1 inch of the foam and the building being mainly open it is already 3-5 deg nicer inside than out, be it warmer or cooler; Being my existing 'house' is only 10 deg different than the outside I'm amazed.  Here most folks run their AC 8 months out of the year so being able to keep the inside temp under 80 will be a huge boon, getting close to closing the place up so we shall see.

Also I am crazy allergic to everything and so is my daughter, we have both been handling and working with the foam and in the building with no adverse reactions and that is also amazing since 10 min in any store is enough to make either of us feel ill, so once sprayed the foam is fairly MCS friendly.

We are looking forward to experimenting more with cob and other materials but it is a challenge here.  There is NO rice, or pumice around the very southern Tip of Texas is an ancient alluvial plain from when the rivers actually flowed.  Cotton, sorghum, cabbage, onions, melons and sugar cane the main crops since 'cheap labor' has sent broccoli and similar food farming south of the border.  Most farmers spray heavily which sends their pests my way, at least the birds and butterflies also like my place   Sadly all my research has led me back to steel, and concrete for construction.  I was shocked to find massive termite tunnels in some insulative foam panels I had been given that were on edge on a pallet, the termites ate right into them!?! 

Thanks for this report, serenity.

I have been wondering about the soy foam.
I am a canary too, and at the moment, I am doing what I must to shield myself from the pesticide in the floors.
I have been wondering if I should put a thin layer of ferocement on the outside or maybe a little foam first, followed by ferocement then bermed with soil.
I have ordered cotton insulation for the inside, and it seems OK but I am worried it will get too wet.

Shellac is a fabulous moisture and poison barrier so I am using that for the interior walls.

I would love to know if the inside walls are staying dry after you have been inside for a week or so.
The reason I am asking is that we exhale a lot of moisture like a liter a day and I am wondering if  this becomes a problem.

Thanks for your report. It is perfectly timed.

jeanna

I see you settled on foam great choice;

    I have developed a weird creative re-use insulating system that is based on discarded non re-recyclable
mylar chip bags,aluminum foil,candy wrappers and anything else shiny and light,
  take these and fill the open end of a tetra pak soy milk container,tape shut with duct tape
  You have a "Neo-earth brick"  set them in 2x6 studwalls with standard cob primary plaster(at least 2/1 sand to clay mix)
lay up like ordinary brick, will give better insulating value than "Light straw" or Straw clay" that Michael Smith taught me.
  So start saving up your garbage,and insulate your houses with it , it works.
    EVERY BODY Permie,PLEASE STOP using vermiculite in clay for insulation  1.  I doesn't work
2,  It's toxic (Irritant,carcinogen) same with perlite, and pumice,,  although at least those two are somewhat effective.
  USE RED LAVA...same in your garden potting soil, also red lave breaks down into valuable nutriants.

as experimenters,we keep tearing apart our ovens and rocket stoves,or they fall apart,children are often a part of this work
and we are creating time bombs or dangerous irritants for no good reason accept old world ways.

WrittenInHeaven wrote:
I have an existing metal building I'd like to insulate and need some suggestions. Thanks.

I have a corrugated metal roof in my animal house I need to insulate. Weight is an issue so I was looking into those spray foam kits but the toxins do concern me. What is this soya spray foam? Do you have a link so I can see if it's available in the UK ?
The roof is pretty large (80sqm) and those kits only seem to cover 15sqm or 20sqm, which would make it really expensive.
Are there other options?
I had thought about putting chicken wire over the battens and stuffing straw tightly into the space but I don't know if that would be effective enough to stop condensation. Any thoughts?

If it is available, bubble-foil insulation works very well as a radiant, vapor and condensation barrier. I had it installed in my attic between the rafters under the roof deck. It also forms a channel between the trusses to vent air from the soffit vents to the ridge vent. It helps to keep my second story addition quite livable on days with full sun.

Take a look here for some ideas: http://www.farmtek.com/farm/supplies/ExternalPageView?pageKey=EXTERNAL_PAGE_3005

(I am not endorsing the FarmTek site. They do have some very innovative products and ideas. I priced them, but I was too far away to get a good shipping rate and ended up purchasing from another supplier.)(In double checking my reference before posting, I have been unable to access the farmtek website. I assume it is a temporary problem.)


About rice hull insulation, you may wish to review these documents:

http://www.thelaststraw.org/backissues/articles/Rice%20Hull%20House.pdf

http://esrla.com/pdf/ricehullhouse.pdf


Also, though off topic, please take a moment to check out Paul Olivier's website:

http://www.esrla.com/

Not all vermiculite is bad, or toxic or carcinogenic. But some is, or was. Zonolite is an example of the bad stuff.

The difficulty is that it's impossible to tell by looking. You have to do serious lab testing...

Finest regards,

troy

A member named dan murf created a thread called "grain bin house." He has made good progress and is not just dreaming or speculating. I'm sure that he will have researched this subject and may have photos as well.

Hiring best insulation person for constructing roofs and reconstructing a building .They have a higher knowledge . and remember Unroll several rolls of insulation to give yourself a visual idea of the height and width of the insulation rolls.

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