Floor slab removed afterward, reinforcement visible

Hello,

about two weeks ago, the foundation slab was poured for our house construction. Overall, the work was done very cleanly and solidly, as far as I can judge. This week, the masonry work on the ground floor was started. It was found that the formwork for the foundation slab was not properly angled. As a consequence, the foundation slab slightly protruded below the masonry on one gable side. The overhang increased from 0 to about 6 cm across the width of the house.

Now the general contractor has chipped away the overhang along the width of the house. Reason: otherwise the insulation would not fit. Background: we are also having brick cladding done. The bricks rest on the frost skirt, which is about 80 cm deep.

Where the foundation slab was chipped away, the reinforcement is partially exposed. How should this be assessed? Is it sufficient to paint over it with the bitumen coating?

Reinforcement made of steel is susceptible to environmental influences and high heat development, for example from fire. Therefore, it must be protected by a sufficiently thick concrete cover, which is usually between 2.5 cm and 5 cm. The concrete cover ensures

the bond between concrete and steel
corrosion protection
and fire protection
In the surface-near area, the concrete must be designed to be compacted and cured in order to avoid large crack formation. The necessity of thorough and sufficiently long-lasting curing is explicitly pointed out in DIN 1045-2. The curing duration is specified in DIN 1045-3 and is determined based on the strength development of the concrete. According to DIN 1045-2, the strength development is divided into fast, medium, and slow hardening.

If the aforementioned conditions are met, a corrosion-protective and alkaline environment is ensured, which guarantees the load-bearing behavior throughout the entire service life. The concrete cover is defined by the nominal dimension. The minimum dimensions of the concrete cover depend on the environmental influences and the diameters of the steel reinforcements. When using aggregate with a grain size > 32 mm, the measure of the concrete cover must be increased accordingly, as well as for surfaces yet to be treated such as exposed aggregate or scarified surfaces, and for components with increased fire protection.

The reinforcement layout is specified in DIN 1045 [Tragwerke aus Beton, Stahlbeton und Spannbeton]

Hi.

Strictly speaking, that would mean: tear down the masonry and the floor slab, everything new. Ouch.

I rather think no - but simply pre-gluing insulation is also not advisable.. does the insulation also rest on the frost skirt with you?

Strictly speaking, that would mean: tear down the masonry and floor slab, everything anew.

For me, that means: you have a problem that a forum cannot solve. If the construction company says "tear down, new, at our expense," then that's good. If they say something like "we can handle that, we've always done it that way," then you should urgently(!) get an expert(!). They should assess the situation and say what needs to be done. You are welcome to report back here!

I rather think no - but simply pre-gluing insulation is also not advisable.. is the insulation also placed on the frost skirt with you?

Hello.

Yes, the insulation is also placed "below" on the frost skirt. It would basically conceal the defects in the base plate.