Is it possible to widen a door opening in a blue concrete wall (by about 1 cm)?

[Enber]

Hello!

I'm looking to install a more secure external gable door on our ground floor, and the model I'm considering (Swedoor with additional RC3 classification) is well-priced but unfortunately has awkward dimensions. My door opening is 90 cm wide, the standard outer dimension for Swedoor frames is 888 mm, but the RC3 classification adds 12 mm, which is exactly the same as my door opening.

The problem, therefore, is that if the door even fits, it would be very tight with the adjustment allowance...

So the question is: Can the door opening be expanded by about 1 cm (preferably on one side) without affecting the wall's stability, and if so, what would be a suitable tool for such an operation?

 

[toolman77]

How is the wall constructed today around the frame? Is it cast, plastered, or raw blåbetong?

Cutting off 1 cm of blåbetong is easily done with a chisel on the hammer drill, an angle grinder, a chisel, a reciprocating saw with the right blade, etc. What determines it is what you have and how the surroundings look. What can you reach with?

I would advise against the angle grinder because it creates an incredible amount of dust, but it's fast and easy to get a straight edge.

I would find it very fun to try one of these in concrete:

 

[Enber]

Thanks for the response! I took a few pictures of how it looks. It is raw blåbetong from what I can see after a bit of carving with the knife, with some filler + paint on it. I hope my handwriting is legible.

 

[Enber]

Should probably add that the exterior is a brick wall (with a small air gap between lightweight concrete and brick), so there I can probably just place the frame against the inside of the brick opening.