Door opening in hollow concrete

[MVJK]

Hello,

We have made an opening in a wall in the basement, which is concrete block, and installed a door.

Now it's time to tidy up, and I'm wondering what I should do with the corner of the door opening.

Do I use some type of adhesive or mortar and then filler at the end to get a nice 90-degree corner?

 

[anders07]

If it's an interior wall, plaster of gypsum is easy to use. Apply a base layer first, insert a metal "corner bead" and smooth it out. Then wait until the plaster begins to set slightly and finish to the desired texture.

Vacuum away any loose dust carefully and dampen (almost wet) the surface before you apply the plaster of gypsum.

 

[MVJK]

Great, thanks! I'll get started with it.

 

[MVJK]

If it's an internal wall, gypsum plaster is easy to use. First, plaster up, insert a "plaster corner" in metal, and smooth it out. Then wait until the plaster begins to set a bit and finish to the desired texture.

Carefully vacuum away loose dust and dampen (almost wet) the surface before applying the gypsum plaster.

Does the surface need to be primed first?

The entire concrete wall is also quite uneven; can I use hopspika there as well to even everything out? Then go over with some filler to fix small irregularities.

 

[anders07]

Does the surface need to be primed beforehand?

The entire concrete wall is also quite uneven, can I use hopspika there as well to smooth everything out? Then go over with a little putty to fix small irregularities

No, just dampen it (and dust it off thoroughly), no primer.

It's best to get it smooth with the plaster, but if there won't be any moisture, you can apply putty.
Keep in mind that plaster becomes very hard and cannot be sanded!
You can apply the plaster in layers, but then you need to leave the underlying layer "uneven" so the next layer adheres properly.