The Angle of your Dangle… ;)

I recently received  an email from a guy who wanted to build a Green roof on top of his ISBU Home.

He’s using SIPs to create his roof. Why? Because he’s S-M-A-R-T. 🙂

However, “green roofs” are HEAVY. You have soil (sometimes, as Kim pointed out, “engineered” using perlite or vermiculite), sod, planting materials, decking… the water in the soil… the weight of a torrential downpour… blah blah blah…

By the way… thanks, Kim! 🙂

This is the diagram of what he wants to do.

Green roofs come in all shapes and sizes. The rule of thumb is to divide them into three categories;

• Extensive – less than 6″ thick
• Semi-Intensive – 25% above or below 6″ thick
• Intensive – Over 6″ thick

The actual Green Roof weight can range from about 35 – 150 pounds PER SQUARE FOOT.

That means that even using SIPs, he has to reinforce the roof, to carry the load.

You CANNOT just chuck potting soil up on top of the corrugated steel and expect the earth to act as insulation. That’s ridiculous.

Beyond that, the corrugated steel isn’t designed to be used for that purpose. By itself, it won’t support that kind of load. You’re courting disaster.

You have to build a REAL roof, first.

And even though SIPs (my roofing material of choice) are “Tonka Tough”…

SIPs WILL NOT carry that kind of load without some kind of support.

I suggested he think about building a steel subframe to support his SIPs,  thus supporting the weight of his Green Roof. I suggested that he even explore using “simple” angle iron stock.

Shortly after that, all heck broke loose in my email in-basket.

People started hollering about how “limited” the sizes of angle iron are.

What? I’ve never found this to be true!

Sure, sometimes I have to source a piece of steel stock specific to my requirements, but it’s all good. Steel doesn’t fall from the sky, except maybe at Skyway Steel, where I got that terrific photo!

Here’s a table that will give you some ideas about WHAT SIZES of angle iron are readily available.

Included is thickness and dimensions of the angle iron stock, the weight of the steel per 20′ section and some pricing. Disregard the pricing as steel is moving up and down all the time. When you need the steel, price it locally.

Or better yet, find some to recycle. You’d be surprised what you can find, if you really go look for it.

Angle Iron		Wt.		Price		Price		Price
size-1 / 8″x		wt20′		Per/ft.		/10ft		/20ft
1/2″ x 1/2″		7.6		$0.75		$5.50		$10.00
3/4″ x 3/4″		11.8		$1.00		$5.50		$11.00
1″ x 1″		16		$1.25		$6.50		$12.00
1-1/4 x1-1/4		20.		$1.50		$8.50		$15.00
1-1/2″ x 1-1/2″		25		$1.75		$10.50		$19.00
2″ x 2″		33		$2.00		$14.00		$25.00
Angle Iron		Wt.		Price		Price		Price
size-3/16″x		wt20′		Per/ft.		/10ft		/20ft
1″ x 1″		23.		$1.50		$9.00		$17.00
1-1/4″ x 1-1/4″		30		$2.00		$11.00		$20.00
1-1/2″ x 1-1/2″		36		$2.50		$14.00		$26.00
2″ x 2″		49		$3.00		$18.00		$32.00
2-1/2″ x 2″		55		$4.50		$24.00		$45.00
2-1/2″ x 2-1/2″		61		$4.00		$23.50		$43.00
3″ x 2″		61		$4.00		$23.50		$43.00
3″ x 3″		74.		$5.00		$28.00		$52.00
Angle Iron		Wt.		Price		Price		Price
size – 1/4″x		wt20′		Per/ft		/10ft		/20ft
1″ x 1″		30		$2.00		$12.00		$22.50
1-1/4″ x 1-1/4″		38		$2.50		$15.00		$28.50
1-1/2″ x 1-1/2″		47		$3.00		$17.00		$31.00
2″ x 2″		64		$4.00		$22.00		$42.00
2-1/2″ x 2-1/2″		82		$5.00		$29.00		$54.00
3″ x 2″		82		$5.00		$29.00		$54.00
3″ x 3″		98		$6.00		$34.00		$64.00
4″ x 3″		116		$7.00		$43.00		$80.00
4″ x 4″		132		$8.00		$49.00		$86.50
5″ x 3″		132		$18.00		$49.00		$86.50
Angle Iron		Wt.		Price		Price		Price
size-5/16″x		wt20′		Per/ft.		/10ft		/20ft
3″ x 2″		100		xxx		$41.00		$77.50
4″ x 3″		154		xxx		$60.00		$110.00
5″x 3″		164		xxx		$66.00		$125.00
6″ x 4″		206		xxx		$90.00		$160.00
Angle Iron		Wt.		Price		Price		Price
size-3/8″x		wt20′		Per/ft.		/10ft		/20ft
2″ x 2″		94		xxx		$35.00		$65.00
2-1/2″ x 2-1/2″		118		xxx		$44.00		$80.00
3″ x 2″		118		xxx		$44.00		$80.00
3″ x 3″		144		xxx		$58.00		$105.00
4″ x 3″		182		xxx		$74.00		$140.00
4″ x 4″		196		xxx		$79.00		$150.00
5″ x 3″		196		xxx		$79.00		$150.00
4″ x 6″		246		xxx		$100.00		$190.00
6″ x 6″		298		xxx		$125.00		$220.00
Angle Iron		Wt.		Price		Price		Price
size-1/2″x		wt20′		Per/ft.		/10ft		/20ft
6″ x 6″		392		xxx		$165.00	1	314

As you can see, there are lot’s of options.

Just do your homework and then use your head.

William H. Johnson said: “If it is to be, it is up to me.”

Dedicate yourself to being dedicated to yourself. Think things through until the solution is reached. It’s that self-reliance and self-responsibility that will guide you through hard times.

That is all. End of transmission… 😉