Awning on steel beam

[Derbyboy]

Hello,

I am considering installing an awning facing south. The awning needs to be 500-600 cm with a projection of 300-350 cm. I have a flat roof with an eave, so the natural thing would be to install the awning (70-80 kg) on the eave.

I suspect that the wall (with windows) on which the roof beams are situated is somewhat under-dimensioned. I can, among other things, see cracks on the inside by the windows, which most likely occur because the roof is too heavy for the wall to allow any margin to install an awning. Especially considering that there can be significant forces transferred to the eave with such a large awning.

Therefore, I'm considering whether I could instead weld a beam with two legs that I "place" against the eave (see sketch). I'm thinking about what dimensions I would need for such a beam with a span of 500-600 cm. I can handle the shearing force with small supports from the house.

What do you think?

black: eave
purple: intended construction

 

[Derbyboy]

This is what the facade looks like:

 

[Olf Oggler]

As is my custom, I'll hijack the thread and ask a curious question

Which awning of that size should one buy to get the right quality for the money? I'm thinking about awnings. But I have no idea where to start looking.

 

[Derbyboy]

I haven't gotten that far, but there are x number of threads discussing just that issue. Try using the search function at the top. Search for markis and read the introduction of the threads.

I will probably choose a cheap one from hornbach.

Good luck

 

[Derbyboy]

Anyone?

 

[jonaserik]

Anyone?

Hornbach has them. They're large and have a motor. Such an awning has a solid and tough twist in the mounting; I have one that is 6X3.5 meters with 4 mounts using a continuous 16 mm threaded rod on the gable + some reinforcement inside. The brackets for attaching the awning are about 150 mm and 100 mm between the holes. The awning's support arm is a 40 mm square and can handle the torque, so a 50X50 square can certainly handle it, with welded 6 mm plate pieces for the mounts. The posts should also be 50 X 50 mm and fully welded to the crossbeam. A few (5 pieces) into the wall to prevent it from tipping outward.

 

[Derbyboy]

50x50 then, material thickness?

 

[jonaserik]

50x50 then, material thickness?

6 mm is plenty and preferably galvanized, but galvanizing is a bit difficult to weld, it tends to burn in the galvanizing. So use regular steel/iron painted with anti-rust paint and then the color you want. Don't forget that the posts should have a foot underneath them about 10x10cm and be attached to the decking.

 

[Derbyboy]

Thanks, I probably won't attach it to the deck but instead cast a foundation under the deck. Rock at about 80 cm from the bottom of the deck. This way, I can make the construction very rigid, i.e., minimal shift towards the house and outward.

 

[jonaserik]

Thanks, I will probably not attach it to the decking but instead cast a foundation under the decking. Bedrock about 80 cm from the decking underneath. In this way, I can make the construction very stiff, i.e., minimal movement towards the house and outwards.

Some 16 irons in the rock that are cast into the concrete and something that goes up into the post during casting.

 

[Derbyboy]

Ah, make two molds and then I'll set the legs in the concrete. When I'm tired of it, I'll bring out the angle grinder.

10-12mm rebar is sufficient. I can make the mold 40x40 and 50 high.

 

[jonaserik]

Eh, I'll make two molds and then set the legs in the concrete. When I tire of it, I'll bring out the angle grinder.

10-12mm rebar will suffice. I can make the mold 40x40 and 50 high.

That should turn out well.

 

[Derbyboy]

Just need to find someone who can weld

 

[jonaserik]

Just need to find someone who can weld

And do it on-site before it's erected, as it's difficult to transport such a construction. Just make sure it's exactly 90 degrees between the beam and post, and that they align straight down.

 

[Fairlane]

That's how it's set up at my place, with a substantial beam that the irons sit on. It's obviously a completely different construction, but maybe it gives an idea of how sturdy your construction needs to be. In this case, awnings have been on that beam for many years, and there's no visible wear. Unfortunately, the previous awnings were blown apart. Now I have a 5x3 from Hornbach, which I installed last year. I'm planning to add a 4x3 next to it. I think I paid around 6000 for it last year and I'm satisfied. It's supposed to withstand wind according to class 2, which is good for that price range. I'm planning to add another one and then a sun sensor and a wind sensor so I don't have to control it manually.