I'm not following what you're trying to say, but fiberglass bat insulation (maybe you're not talking about bat??) requires air to insulate. If you smash it, the R value becomes almost nothing. For that matter, at temps below 40 the R value begins to drop by about half.

Steel buildings also should not be spray foamed.

Most new steel buildings are spray foamed here for insulating

 

Spray foam cost here is astronomical, likely due to demand.

Wood framed here, strap bottom of trusses, ceiling tin, blow in cellulose or fibreglass. R60 for cheap cheap cheap.

 

Steel buildings also should not be spray foamed.

It's done here in my area of Michigan. They put up a plastic wrap (similar to what you see on outside of houses before siding is installed), then the steel siding. The foam isn't touching the steel per se, which allows the steel to expand/contract with fighting the foam with the change in outdoor temperatures, is what I have been told.

Larry

 

My entire second floor of my house is spray foam...4-6" of closed cell foam in the wall cavities and ceiling angles, and 8-10" open cell in the ceiling joists. Every square inch of external surface is foamed. We had an energy audit with a blower door test done before and after the insulation and the extent to which it tightens your house up is phenomenl. But I have over $6k in insulation up there too and I think it is worth every dollar.

The company I was talking to about a steel building (General Steel) definitely did not recommend spray foam insulation on steel buildings, but that may have been without the plastic wrap?

 

My entire second floor of my house is spray foam...4-6" of closed cell foam in the wall cavities and ceiling angles, and 8-10" open cell in the ceiling joists. Every square inch of external surface is foamed. We had an energy audit with a blower door test done before and after the insulation and the extent to which it tightens your house up is phenomenl. But I have over $6k in insulation up there too and I think it is worth every dollar.

The company I was talking to about a steel building (General Steel) definitely did not recommend spray foam insulation on steel buildings, but that may have been without the plastic wrap?

the only draw back I've heard is if you spray foam directly to the steel if you have to replace the steel because of damage from hail etc you would have to reinsulate as the foam is stuck to the steel.

 

I spray foamed the walls and ceiling of my shop. Its amazingly tight. Which can be a downside at times. Spray some carb cleaner or another chemical and you call often still smell it in the shop 24 hrs later..

 

the only draw back I've heard is if you spray foam directly to the steel if you have to replace the steel because of damage from hail etc you would have to reinsulate as the foam is stuck to the steel.

We did a hail job for a customer last here and tinned right over after removing the screws. Worked well and after a year no visible signs of issues. Only way to do it as the whole building was a wood structure spray foamed inside.

 

I've seen spray foamed steel for sale locally that was clearly pried off purlins, looks like a pain in the rear to work with. Seller was asking 1$/ft2 claiming is was a great deal.

 

You won't get hail damage on steel it the foam is right on the steel. It is hard. Might have paint issue.
Mine is on the steel, down side is it looks weird on the outside, like it shrunk and pulled the steel or something.
How often have I ever pulled a sheet off a building? Never, just saying.

 

Foam doesn't expand and contract like steel. Here is a formula for how much steel expands/contracts with temperature change:

Use a thermometer to measure the change in temperature in degrees Fahrenheit. For example, if the original temperature was 70 degrees Fahrenheit and the final temperature was 75 degrees Fahrenheit, you would have a temperature increase of five degrees.

Multiply the temperature change by 7.2 x 10-6, which is the expansion coefficient for steel. Continuing the example, you would multiply 0.0000072 by 5 to get 0.000036.

I think it would be about an 1/8" on a 16' piece of steel with a 90 degree temp change.

Larry

 

Some guys are using house wrap under the tin then spraying to the house wrap just for easy sheet removal later. Seen this on another forum.

 

I wish I went with a pole barn. With a steel building, I am limited to a few companies to buy replacement panels. If I need a replacement panel, I will have to order it online and delivery of such a bulky item isn't cheap. I ordered a quonset hut kit and I wish I hadn't. I have photos of my progress at: diysteelbuildingkit.org

 

When comparing all-steel buildings to pole barns, each has its pros and cons.

Steel Buildings are durable, low-maintenance, and fire-resistant, making them a long-term investment, although they may require a higher initial cost due to the concrete foundation

Pole Barns, on the other hand, typically have lower upfront costs and offer flexibility in design, but they require more maintenance to prevent issues like rot and pest damage

Ultimately, the choice depends on your budget and specific needs, including aesthetics and long-term plans. For a detailed comparison, you can check out more on resources like Building Elements and Outdoor Options.

 

Currently fabricating a new hayshed . Outside footprint will be 87 x 184.5 (84 x 184 centre to centre on the footings). Got the footings poured a few weeks ago now. I finished off the trusses (I think) yesterday and are now sitting here looking at a heap of steel beams I need to drill and dress.
doing it in my 80x40 workshop. Squeezing 46 foot clearspan trusses through a 20 foot door was fairly easy after doing the same with the 18 42 foot roof trusses.
It's a massive job on your own. 12hr days 7 days a week. I enjoy the engineering challenge. Not sure if I'll enjoy putting it up as much.

 

 

Getting there.....Painting some whilst still making others. It's been a huge job....And I haven't even got to the hard bit yet....

 

Going together nicely. 99.99% on my own. As a farmer I'm used to doing the work of at least 3 Muppets. So if you use your brain there's nearly always a solution for tricky bits.

 

It's 32 foot to the top. I made an adaptor to lift my man basket another 4 feet higher.

That was after making a lifting attachment for the forks to put the trusses up with Its bolted to the back of the adjustable forks. Meaning I had another 3 feet of lifting height , plus the forks have sideshift.

Best thing I've ever made was those forks.

 

That's very impressive. Usually takes a crew of 3 or 4 men to build them and that is after someone else manufactured it.

 

It's been 12 to 13hr days , 7 days a week for 2.5 months solid. At the end of most days I'm totally stuffed. Did 44 8 inch roof purlins yesterday plus 40 purlin braces. Should just about finish the majority of the roof structure tomorrow. Been pushing hard to get done what I can as it's not far off silage season here.

 

Diddle, often I find reading your posts makes me feel really tired and inadequate. I suspect you snarfed some of that English biotech and cloned yourself 20x. Also lust after your shop tools!😎

 

Upper Midwest US we are cutting corn silage now. Central states are starting combining corn and soybeans. Are you talking about corn silage?

 

No. Grass and pasture. Some cereal crops as well (oats, wheat etc)

 

 

Started chucking a bit of tin on today. Of course the wind was blowing against me and the young bloke the entire time. Would've been doing it on my own as per usual. But it was physically impossible to get 6.7m sheets under the flashing and lift it at the same time. Even I'm not that good...

 

Looks good. Jealous of that space.

What's the snow load rating on that roof? Hahaha

 

It's fantastic..... Since it doesn't have tin on it yet🤣🤣🤣