You probably don't need to worry about this issue, but if you are planning to buy an apartment in an old building in Spain you should be aware of it. Between 1950 and 1980 quite a few buildings in Spain used concrete with over 35% alumina. Combined with CO2, humidity and the right temperature this concrete becomes porous and less resistant and could even lead to the collapse of the building. Sometimes this happens when building activities nearby affect the building. And I hate to say that this happens too often. This problem is known in Spanish as "aluminosis". Just today this happened in Hospitalet (Barcelona) with a building that have been repaired because of "aluminosis" 8 years ago, causing one death. There was some construction going on nearby.

http://www.elpais.com/articulo/espan...epinac_13/Tes/

You could find more information about this issue here:

http://groups.msn.com/ALUMINOSIS (in Spanish, sorry!)

Hmmmmm, I was in Gandia Playa the other day and saw a building had collapsed for no apparant reason .... I wonder .....

Uhm!!! Maybe it was a gas explosion. This is the standard way to deal with these problems. We are so creative around here.

Looked really wierd as there were still pictures up on the remaining walls, and a bookcase on another wall

was that by Burger King ? I saw that one and thought it was strange that they had only demolished half the building - so it collapsed

Thats the one, yes.
I doubt it was demolished as there were still personal effects on the walls, headboards, pictures and iirc a book case or two

yes I did think it was strange - cant find anything on the internet about it - have a friend who lives that way so will ask her when I see her next