Do I need to prime before plastering leca

[Hammare&Spik]

Hi, I searched for "grundbruk" at Byggmax and Bauhaus. They have both stopped selling it as it apparently didn't sell well. I'm planning to plaster Leca outdoors. Now I'm wondering, can't I just skip the priming step? The priming is supposed to make the plaster adhere better (as I understand it).

What do you think?

 

[atomlab]

Search for rödgrund and you will find what you need.

 

[Hammare&Spik]

Search for rödgrund and you'll find what you need.

Do you think the result will be good if you skip priming beforehand?

 

[atomlab]

Red foundation is easier to achieve a better base layer, is more charming to expand with, and it makes the joints less visible.

 

[PNO]

Before priming mortar, such as red primer, was available pre-mixed, one would mix their own priming mortar from cement and sand. It works just as well today. The thing with red primer is that it is colored, making it easier to see that it covers and that you haven't missed any spots.

 

[Tjrex]

You will see the leca/mortar through the plaster if it is a façade you are plastering. Follow the instructions/system from the manufacturer you choose.

 

[Hammare&Spik]

The plaster is from Bauhaus. But they no longer sell the base plaster.. So it will probably be Weber base plaster and Bauhaus plaster. Feels so-so, actually.
Considering skipping the priming.
It's a 30cm high garden wall I'm going to fix.

 

[Tjrex]

https://www.byggahus.se/forum/threads/varfoer-ser-man-stenarnas-moenster-genom-putsen.263466/

 

[kniv]

Base plaster with cement mortar A

 

[Drburr]

Rödgrund is phased out, webers is now called grundningsbruk kc. But as stated above, cement mortar works well as priming. Make sure to apply it with a brush or scrape the surface so the next layer gets a good grip. The joints will show through if you don't prime.

 

[Hammare&Spik]

Rödgrund has been phased out, Webers is now called primer mortar kc. But as mentioned above, cement mortar works well as a primer. Be sure to spread it with a brush or roughen the surface so the next layer adheres well. The joints will show if you don't prime.

What is the difference between cement mortar and primer mortar kc?

 

[kniv]

What is the difference between cement mortar and kc primer mortar?

Not much. All mortars have a mixture of lime and cement. Hence, some are called kc. Cement mortar A contains both lime and cement, even though it is called cement mortar.

But this also makes it a bit unclear, as all have lime and cement but the ratio varies depending on the application area. The A/B/C classification is being phased out in favor of the M classification where they are specified in 10/2.5/0.5, among others.

A/M10 is best suited for what you want to do.

 

[Hammare&Spik]

Not very much. All mortars have a mix of lime and cement. Hence some are called kc. Cement mortar A has both lime and cement, even though it's called cement mortar.

But this also makes it a bit unclear, because all of them have lime and cement, but the ratio is different depending on the application area. The A/B/C classification is being phased out in favor of the M classification where they are specified in 10/2.5/0.5, etc.

A/M10 is best suited for what you want to do.

Awesome, thanks!!

 

[kniv]

Awesome, thanks!!

If you find the post useful, please mark it as the best answer so that others can find it more easily in the future.

 

[Drburr]

What is the difference between cement mortar and base coat mortar kc?

The base coat mortars from Finja and Weber are low-alkaline and therefore also work on lightweight concrete. Cement mortars are based on gray Portland and should not be used directly against it. The M class refers to masonry mortar, while plaster mortar is categorized under CS 1-4 as I recall.