Concrete edging reinforcement is cut

Hey guys

I have the following "problem". I have a concrete ceiling that extends over the terrace from the house. The original plan was to make a flat roof on the canopy. For this, the emergency overflows as well as the manhole openings and the cutouts for the connections to the water gutter were made.

However, for aesthetic reasons, we decided to go with a metal roof instead. As a result, the overflows and cutouts are unnecessary.

My roofing company has now closed the emergency overflows and cutouts with Styrodur and foam so that the whole thing can be plastered.

However, no one thought about the cut reinforcement. Since the area was open for several weeks and also got wet, the reinforcement at the cut point is of course rusting.

Should this have been sealed somehow or will it not rust further? My shell constructor says nothing will happen. It will just rust a little on the surface and that’s it.

Water doesn’t get there directly anymore. However, maybe humidity since I don’t think the foam has enough of a barrier.

Hope you can help me with this.

I have already thought about cutting the Styrodur out again, then removing some rust from the reinforcement at the cut point with a wire brush and then applying some cement over it so it is airtight sealed. What do you think?

Best regards Chris

Hello.

The Styrodur actually has to be removed and the holes have to be filled with concrete so that the necessary "concrete cover" is restored. However, you don't need to treat the steel, as it would not help at all because you only have access to the cut surface. Corrosion protection is achieved by separating the air oxygen and the alkaline environment in the concrete.

If the steel rusts, it expands and thus breaks off the concrete. This way, the rust works its way through the entire construction.

Okay, first of all, thanks for the response.

The problem is that the roof is already on. Because of that, unfortunately, I can no longer install formwork inside to pour concrete. Does the concrete cover also have to be maintained if no water gets there?

For clarification: I stuffed what was planned as a flat roof with insulation wool. A wooden structure would be attached to the upstand, and a sheet metal roof mounted on it.

Regards, Chris

Does the concrete cover also have to be maintained if no water reaches it?

Yes. It has little to do with water. Humidity (and air) is enough. Keyword: Carbonation.

Okay great thanks. Would you then drill a few holes and insert iron rods so that it bonds well during concreting?

What would be suitable for that? Cement, mineral concrete...?

Best regards Chris

What I would also like to know. Does this carbonation always take place? As far as I read on the internet, this always happens with reinforced concrete unless the concrete is sealed with special agents.

Thanks in advance

Best regards Chris