Steel Corrosion in Reinforced Concrete

[Rhys]

We have cracked tiles on an external, exposed balcony, which got worse over the winter because of heavy rain and frost.

Now some of the concrete on the edge of the balcony has broken away (spalled), exposing some reinforced steel rods, which have clearly rusted.

The same problem has happened on a lintel over an internal garage door - does this need urgent action?

Someone has mentioned rust-inhibitor products. Any further advice would be appreciated.

I did have a survey by a French company when I bought the house - would I be able to make a claim against them?

[Ron Avery]

All concrete deteriorates over time, it is the effect of moisture on the rods, you only have to look in the UK to see the number of buildings being demolished because of concrete cancer

All rods and grilles have surface rust when installed so if that is the problem treat with an inhibitor or hammerite type product where exposed and patch repair, if however the rods are eaten through they are not reinforcing and so weakening the whole structure, so you do need to take action quickly if they are load bearing like the lintel, but to replace that  is not a major problem for a competent builder or D-I-Yer

You may have grounds for a claim against the surveyor depending on whether the contract you had was for a structural survey or not, if the damage that you can now see was evident at the time of the survey and the terms of the survey (get out clauses)  If the damage you can see is only now evident and there were no tell tale rust lines on the concrete,  I doubt that you have grounds for a claim.  

[Mysfloss]

In the sika range of products there is a choice to suit most of the repair problems for concrete www.sika.com and click on country for language that you want..There are other manufacturers as well