ᐅ Painting Concrete Walls and Lime Plaster in the Basement Yourself – Preparations?

Created on: 13 Jul 2017 16:13
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AndreasPlü
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AndreasPlü
13 Jul 2017 16:13
Hello,

this weekend I plan to paint three basement rooms in our new build as a DIY project.

The walls are made of concrete (watertight concrete) and lime plaster. The ceilings are reinforced concrete and have already been skimmed.

My planned procedure is as follows:

- Sand the concrete walls
- Brush the walls with a stiff broom to remove dust
- Lay protective fleece on the floor
- Mask light switches, exposed electrical wiring, windows, etc., covering them with plastic sheeting and sealing the edges with tape
- Then start painting the ceilings, first the corners with a brush, then the surface, working in square sections and painting each square in a crisscross pattern
- Then paint the walls, working away from the light source
- Repaint the lime plaster walls without sanding
- Probably apply a second coat as well.

Am I on the right track with this, or is it going to turn out badly?
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Nordlys
13 Jul 2017 16:18
Primer. First apply primer. Otherwise, it will peel off again. Karsten
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AndreasPlü
13 Jul 2017 16:33
Nordlys schrieb:
Primer. First primer. Otherwise, it will peel off again. Karsten

Thanks for the tip. I just looked into the substrate preparation. It states here

"Plasters of mortar group PII and PIII/compressive strength according to DIN EN 998-1 with at least 1.5 N/mm2: Coat solid, normally absorbent plasters without pre-treatment. On coarse porous, sandy, absorbent plasters, apply a primer coat with OptiGrund or CapaSol."
or
"Concrete: Remove any existing release agent residues as well as chalking, sandy substances."


As I said, the non-concrete walls have a sprayed lime-cement plaster. Is priming still necessary?
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Nordlys
13 Jul 2017 20:24
I would do that to reduce its absorption. If it’s not necessary, it won’t hurt. Primer is also inexpensive. Karsten
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AndreasPlü
14 Jul 2017 09:03
Ok, in the Caparol product information for the corresponding primer it says "For professional use only. Can cause serious injury or be fatal if inhaled. Etc." That doesn’t sound very good. Can I use a different primer, for example one from a hardware store?

I also read somewhere that the first coat can be diluted with 10-20% water, which is supposed to replace the primer (?).

Additionally, I found a small wall made of solid gypsum boards. I assume I need to apply a primer there, or is there another option?
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Nordlys
14 Jul 2017 09:15
Honestly, you can use any primer, even the ones from Bauhaus or OBI. 10 liters (about 2.6 gallons) for 20,- is more than enough. I’m not familiar with the diluted first coat method, but it doesn’t save any work anyway. Karsten