Coatings on external plasters
The old one was chained on the old church, The exterior plaster was destroyed and replaced with new plaster, made of PII group mortar. Medium grain rapped plaster is to be painted with silicate paint. Please provide the sequence and type of execution of works related to this painting. The following works should be performed in sequence:
1) wytrawienie nowego tynku płynem żrącym;
2) zagruntowanie farbą krzemianową rozcieńczoną werniksem zależnie od nasiąkliwości podłoża;
3) topcoat with silicate paint.
On the old facade of the house, on large surfaces, the paint coating of the dispersion paint falls off. As a result of the study of the substrate, it turned out, that the plaster was made of PIIa group mortar and it slightly flakes off the surface. Please present the sequence and type of works that make up the new paint coating, taking into account the materials used The following works must be carried out in sequence:
1) usunięcie starej powłoki przez zeskrobanie, followed by washing with a suitable remover;
2) thorough cleaning with hot water under high pressure;
3) naprawienie uszkodzeń tynku przy użyciu podobnej zaprawy;
4) wytrawienie naprawionych tynków płynem żrącym;
5) priming with varnish, diluted with water, depending on the degree of liquid absorption by the substrate;
6) painting with silicate paint, diluted with varnish depending on the absorption of the substrate;
7) końcowe pomalowanie farbą krzemianową;
8) usunięcie produktów zmywania i śladów brudnej wody.
Silicate and silicone dispersion paints are also suitable for this type of substrate.
Please justify, why dispersion paints cannot be applied to plasters made of PIa and Plb group mortars?
Plasters made of mortars of this group require a constant supply of carbon dioxide, even after hardening. If the carbon dioxide supply is cut off, plaster becomes brittle over time, and the applied coating falls off the rotten substrate. Dispersion paints cut off the substrate from both moisture, and the influx of carbon dioxide.
The façade of the house was found to have smooth plaster made of PIIa group mortar. The plaster is strong, but there are efflorescences in the plinth zone. The coat of dispersion paint falls off the plaster. Please provide the sequence and type of works related to painting the facade and list the materials necessary for their implementation
The following works must be carried out in sequence:
1) zmycie powłoki z farby dyspersyjnej przy użyciu biologicznie aktywnego zmywacza dyspersyjnego;
2) dokładne oczyszczenie gorącą wodą pod ciśnieniem;
3) usunięcie na sucho wykwitów (after thorough drying);
4) naprawienie uszkodzeń tynku przy użyciu identycznej zaprawy;
5) priming with a suitable primer for plasters;
6) preliminary painting with silicate dispersion paint;
7) surface painting with silicate dispersion paint. An old coat of dispersion paint can also be removed using the water spray technique.
Dispersion paints and paints based on silicone resins are also suitable for coating these substrates.