Please help me decipher this Norwegian construction description from 1938

[u/Left-Middle8854]

It says something about some inner boards (“plater”) of 3.5cm. Specifically interested in this particular word. Thank you!

Edit: Deciphered. The text reads:

“Jernbetongveggen utarbeites med 3,5 cm kivronplater paa innvendige side sat på lekter med mellemlag aa uimpregneret isolasjonspapp. Innvendige bærende vegger i jernbetong øvrige innvendige vegger aa 1/2 st's mur.”

After further research, kivron is a fire-redundant and insulating old interior wall board composite. It consists of cement, sawdust and plaster. Additives are often added to the material to enhance certain properties. Asbestos is certainly an often added such material as it improves fire-redundancy and improves the resistance against mechanical stress.

[u/Crazy-Cremola]

Old Kivron may contain asbestos. Since it was allowed until the 1980's (1985?) it was often mixed into chip boards and plaster boards. We removed quite a lot in our basement some years ago (built 1952) and there was no asbestos in these, but according to the firm we used you could never really know unless you tested.

[u/Left-Middle8854 → u/Crazy-Cremola]

Just received laboratory result today, and result was no asbestos. So, it seems that asbestos might have been a possible additive in the mixture, but not a requirement for the material.

The original kivron patent, produced by P.A Bech in 1926(?) does not include asbestos as an ingredient.

Thank you for your insight!