Reinforce façade area additionally?

Hello everyone,

we are currently at the start of construction and have completed the sampling.
We have sampled the mineral exterior plaster (2mm) in a gray tone and received a note that with a light reflectance value greater than 20, additional reinforcement can be applied, but this is only a recommendation and not mandatory.

The additional cost was estimated at around 3,600 euros... we are now unsure whether to follow the recommendation. Can anyone from the field say something about this?!

Many thanks in advance

A mineral plaster with a thickness of 2mm. Are you sure?

A mineral plaster of 2mm on an ETICS (which insulation material? EPS or mineral wool) I consider to be very detrimental from a structural engineering perspective. It is not sufficiently flexible and cracks easily under mechanical stress, e.g. during hail impact.

An organic plaster is more flexible as long as it is not embrittled by aging. With an HBW of <20, most manufacturers of ETICS/plaster systems generally provide for an additional reinforcing layer. Whether this is sensible and necessary in your situation can only be assessed if all components of the ETICS are specified by the manufacturer. Two reinforcing layers cannot be integrated into a 2mm thick plaster layer.

If it is only about the additional reinforcing layer, the additional costs of €3,600 are initially not comprehensible. A mineral plaster on ETICS should be at least 6-8mm thick or even applied as a thick coat in two layers up to 15mm with a total weight < 30Kg/m2.

You should have the overall structure of the ETICS/plaster/paint system detailed by the provider and also request the building authority approval for this system.

Good morning,

I must have expressed myself incorrectly.
This is what is stated in the specifications regarding the plastering work.

The exterior wall will receive a mineral exterior plaster in the color white. Other color tones are subject to an additional charge and can be determined together before the start of construction according to the contractor's color chart. The surface will be structured by being rubbed out with a grain size of 2-3 mm
The stone used is
The exterior walls will be constructed as solid thermal insulation walls made of 36.5 cm aerated concrete thermal insulation blocks.

Yes, it would be nice if all information were always provided in the initial question. Then it would be possible to respond more accurately.

I agree with you. It was my mistake for which I would like to sincerely apologize... May I still hear your assessment on whether the [Armierung] makes sense?