Still grappling with using the word techo for both 'roof' and 'ceiling'.
Can the term cielo raso mean ceiling in Spanish? If so, is it common usage or a technical term?
And what would be the best way to say in Spanish:
The top floor of my house does not have a ceiling under the roof.
And finally, can techo be used to denote the ceiling of a room on any level of a house, even the basement?
Tricky questions indeed.
I'm no architect, maybe you need the help of one that knows the terminology employed in Spanish. But let me offer you some useful words.
As you have stated, techo can be employed indistinctly for both roof and ceiling.
According to the D.R.A.E
m. Parte superior de un edificio, construcción, habitáculo, etc., que lo cubre y cierra. [roof]
m. Superficie que cierra en lo alto una habitación o espacio cubierto. [ceiling]
But we got a word that means exactly roof and not ceiling: tejado
- m. Parte superior del edificio, cubierta comúnmente por tejas.
To construct your phrase
The top floor of my house does not have a ceiling under the roof.
I think that you can employ another specific word: cerramiento
- m. Arq. Aquello que cierra y termina el edificio por la parte superior.
But I'm not sure if that the technical specific word from an architectural point of view. If your attic got tejado, the underside of that element is the techo of the room. It may be a not fully functional or finished techo, but it's a techo.
Cielo raso is a specific kind of techo. It's a sort of technical name, I didn't know it, but it's registered in the D.R.A.E
Tb. cielorraso.
- m. En el interior de los edificios, techo de superficie plana y lisa.
And last but not least, techo is the ceiling of any room [see definition above], including the basement. Is there a specific word in English for the basement's ceiling?
Techo es lo que cubre o cierra una edificación, sea casa, edificio, etc. Es lo que se ve exteriormente en una construcción.
En arquitectura se prefiere usar la palabra "cubierta".
Tejado es un tipo de techo.
El "cielo raso" es lo que está a la vista y se coloca interiormente por debajo o del techo o en el caso de casas o edificaciones de varios pisos lo que se coloca o se ve por la parte inferior del piso inmediatamente superior. No se considera que sea exclusivamente un término técnico.
Ejemplo de techo SIN cielo raso
In general techo is used, as you say, for both "roof" and "ceiling". We only try to make a distinction when necessary.
Cielo raso or cielorraso is a bit technical, but common enough in my experience. Raso means "flat and smooth" but cielo raso is often understood as a ceiling in general, provided it's a more-or-less continuous surface.
About a good way to say in Spanish:
The top floor of my house does not have a ceiling under the roof.
Since the sentence itself says there's no ceiling, you can treat this in a general way and say cielo raso, which is the most common kind of ceiling. If you do this, then techo should be enough to express "roof", since the contrast should be obvious. If that's not good enough, you could add some detail about the roof; for example, you refer to the beams or rafters (vigas) that support the roof, which should be hidden by the ceiling if there were one:
El piso de arriba de mi casa no tiene cielo raso bajo las vigas del techo.
This is a bit awkward; some people would say something more like
El piso de arriba de mi casa no tiene cielo raso, se ven [directamente] las vigas del techo.
that is, "one can see the roof-supporting beams [right away]".
For your last question, yes, techo can be used to denote the ceiling of a room on any level of a house.
Something that you didn't ask, but that you could find useful, is about collocation and ambiguity. With techo, if you say subir al techo, that basically always means "to go up on the roof"; it never means "to climb [a ladder] so that you can reach the ceiling". If you want to express this latter meaning you need to express it in a different way.
If the roof is flat and/or meant to be walked on, you can call it a terraza. If it's sloped and has tiles, it's a tejado. These are two alternative, more specific ways to refer to a roof, if doing so using techo would be ambiguous.
