Construct (build) cornice on facade at eaves, which material is best?

[GustafWesterholm]

I am building a house with aerated concrete (Ytong) and have chosen to install a cornice at the eaves (stair-like decoration). The two bottom ones are made of aerated concrete and are mortared in place. The top one I need to construct out of some kind of wood. Partly because there needs to be an air gap in certain places and partly because I need to screw the gutter into it. The idea is that all three will be smooth plastered when finished (painted white).

I am considering what material to use. Boards and studs or is it better with some sheet material (OSB, plywood, etc.)? Is there a risk that the boards might twist over time, causing gaps and "ugliness"? If you choose sheets, do they withstand moisture over the years?

How would you have done it?

Attaching picture.
[image]

Did you manage to get your fine corners and details around the windows done later?

 

[rsa]

We cut out "gesims" from super hard froigolit and glued it with outdoor tile adhesive. Then it will be meshed and plastered along with the facade.

That and the end result look super good!! I've been thinking of doing the same for the carport and have another thread just for that: https://www.byggahus.se/forum/threads/eps-xps-frigolit-pa-limtraebalk-och-puts.420686/#post-4273282

Do you need the hard styrofoam XPS or is EPS fine?

Did you put any corner strips on the gesims's "outer corners" before plastering or just mesh?

How did you "saw" the styrofoam, with a saw or with heat?

 

[rsa]

Did you manage to get your nice corners and details around the windows then?

No details on the house's corners or around the windows as originally planned. Most likely, we will skip them. It looks good without

 

[rsa]

Interesting! I didn't know about this with cellulose insulation. Is there a thread where I can read more about it?

You can read about it in several places. Search a bit on the internet and you'll find more information. It's important to get the entire construction right, from the outer roof all the way to the inner roof. https://sjomarkens.se/tejpskolan-bygg-utan-luftspalt/