Rust under concrete balcony

[tomd]

Hello

We have a high set house built in the 1970s with a concrete balcony supported by steel posts and what seems to be thin ridged steel sheeting underneath. There is a fair bit of rust along edges of angle iron which sits above the posts and holds the outer edge of the sheeting. Worse than this I think is the rust along the outer edge of the sheeting - it is completely rusted through. This means that the concrete slab is only supported on the angle iron. It looks to me as if we might have to build a new floor under the existing balcony to hold it all up.

Has anyone dealt with this before? (I can see why newer balconies are made of timber!)

Regards

tomd

 

[Peter 14.7]

Very hard to understand the problem? Any pics?

Peter 147

 

[Michael Croft]

Hi tomd,

Sounds like you have a 'bondek' or 'condek' balcony aka suspended concrete slab. The angle iron supports the bondek, the bondek supports the reinforcing mesh and the concrete whilst it sets. The metal sheeting is aka loss formwork. This may or may not be structural after the concrete is set depending on breed. In some cases the concrete and angle iron are structurally sufficient without the formwork.

So and NB Depending on the span of the slab the rust could be no problem (only cosmetic) or require a rebuild or reinforcing. Your problem will require either a builder or structural engineer to check it out.

Good luck, MC

 

[Jacque]

Hi tomd,

Sounds like you have a 'bondek' or 'condek' balcony aka suspended concrete slab. The angle iron supports the bondek, the bondek supports the reinforcing mesh and the concrete whilst it sets. The metal sheeting is aka loss formwork. This may or may not be structural after the concrete is set depending on breed. In some cases the concrete and angle iron are structurally sufficient without the formwork.

So and NB Depending on the span of the slab the rust could be no problem (only cosmetic) or require a rebuild or reinforcing. Your problem will require either a builder or structural engineer to check it out.

Good luck, MC

Welcome back, Michael
We have missed your wealth of knowledge and informative and always helpful posts. It's great to have someone of your calibre back and contributing!!

 

[Michael Croft]

Ta Jacque,

Glad to be back, two way sattelite broadband helps.

warm regards, MC

 

[geoffw]

Glad to be back, two way sattelite broadband helps.

Good to see you're off that didggy rural dialup- well done!

 

[simonjulie]

Hi Michael
Great to have you back on the forum.
Kind regards
Simon

 

[tomd]

Thanks for your reply Michael

Yes, it may be cosmetic, at least while the angle iron is sound, which it should be for a number of years. I've noticed a lot of concrete balconies around lately which don't seem to be held up by anything other than posts and whatever reinforcing they have inside. I'll get someone to check it out and hopefully only have to remove loose rust and paint with primer and killrust.