Magnesite is the decking material used on stairs and second story walkways. Many buildings in Los Angeles were built in the 1960s that were stucco framed with a magnesite stair case and landing.
For some reason, many landlords have tried to avoid using magnesite because it is a little more pricey than other materials.
Below are pictures of one landing that a landlord pored concrete on top. This is heavy and so the deck started to droop. So, the landlord propped up the deck with 4×4s. It didn’t work and there was serious water intrusion. So, we fixed it correctly with magnesite.
Here is another landlord’s attempt to go cheap and avoid having to replace the magnesite. This landlord used brick and mortar. It does not keep the water out!
So, my suggestion… Do it right! The magnesite lasted since the 1960s. Thats pretty good. New magnesite stairs & decks on a typical 6 unit building cost $6,000 – $10,000 depending on the number of stair cases and surface area. Don’t go cheap or you will just be doing it again in a few years