Is a repair of a concrete roof slab possible?

thenudeone

In my 1950s house I have a 2m x 6m lower ground floor room overlooking a garden with a solid concrete roof slab about 9cm thick. Above the roof is a layer of mastic asphalt which forms a patio balcony. Presumably this was made by erecting shuttering and pouring concrete. Inside the concrete are criss-crossing metal bars.
Due to water ingress or the natural reaction of steel with air over time, the bars inside the concrete have corroded and expanded, causing the part of the roof below the bars to fall away to a depth of 3-5cm exposing the corroded (and in some cases broken) bars.
Is it possible to repair this? or do I have to remove the existing roof completely, pour a new concrete roof, and replace the mastic asphalt; obviously a big job probably into five figures.

FreeBear

Replace is your only long term solution I'm afraid.

With the steel reinforcement rusting, what ever you do will just see more lumps of concrete coming down. The structural integrity of the slab is also in question, and if too much weight is placed on top, it could collapse. Replacing the slab will ensure that it is safe, and gives you opportunity to insulate. Cost wise, I'd expect something in the region of £5,000, so quite a bit short of your "five figure sum".