Using these I-beams for canopy..?

[Anderzzon]

I'm considering building a pitched roof/lean-to on the back of our garage (the window side). I want to be able to back in with the tractor and store some machines, etc., under the proposed roof. I have 4 steel beams lying around that I would like to use in the best way possible to keep material costs down.

Beams:
Length 7.5m
Height 165mm
Thickness about 5-6mm
Marked NP16

The long wall on the back is about 11m and I would prefer the lean-to to cover the entire span.
Then an extension of 4-5m.
I plan to attach a support beam to the wall as close to the eaves as possible. I want the smallest possible roof slope since it will be tight if I am to back the tractor in from the long side.

Any tips on how to use the existing beams and build with as few support pillars as possible..?
I don't want to cut the beams only to realize I could have done it in a better way.

 

[justusandersson]

These are probably INP 16 beams, an older type of profile that is similar to IPE 160. You can cut them to 5 m lengths and use them as primary beams extending directly from the wall. This will create three sections, each approximately 3.7 m. At the front edge, place each beam on a steel column. The maximum load on the column will be just under 30 kN, which most relevant dimensions can handle. Perpendicular to the steel beams and parallel to the wall, install wooden joists, 45x220 C 24 c/c 600 mm, for example. If you want a larger c/c, glulam is required. On top of the joists, add roofing, trapezoidal sheet, rough boarding + felt, etc.

 

[Anderzzon]

What would the construction look like if you use self-supporting roofing sheets instead..?
I found a company nearby that sells TP128. www.lindtech.eu

Would telestolp work as columns..?

(There were actually 5 beams I had by the way )

 

[justusandersson]

Then you should place your beams in two rows parallel to the wall instead. It will require a few more columns. If they don't get too high, telegraph poles can handle quite large loads. Self-supporting roofing sheet can certainly handle a c/c distance of 2.5 meters. I don't think you need as high a profile as TP128. I can calculate a bit more on it tomorrow.

 

[Anderzzon]

One idea is that the bearing beam attached to the wall can be wood. The garage has a loft with large joists, so it should be possible to bolt a large joist there with through-threaded rods in them.

There is also the possibility to cut and splice two beams so that the total beam length becomes 11m.

 

[justusandersson]

One thought is that at least the beam attached to the wall can be wood.

That's what I assumed.

You will need to cut and splice two beams together so that the total length is 11 meters. Each such spliced beam should rest on 4 pillars with approximately 3.7 meters distance between them.

If you have two rows of steel beams with 2.5 meters distance, you can use the thinnest version of TP128. Theoretically, you could manage without the middle row, but then the sheet will be thicker and more expensive, so there isn't really a saving in that.