Hi

I am travelling to Spain and one of my air b n bs has not fire alarm. Quite common it seems in Spain as hardly any have them when I search. I cannot find a travel fire alarm only CO alarms. However, ideally I would like to bring a 2 in 1 with me. I bought a 2 in 1 alarm that is battery operated and has an on/off button so I can turn it off on the plane. However, I know ideally it should be screwed to the wall/ceiling but I cannot do this in a place that isnt my own. If I leave it high up on shelf on it´s side aganst a wall in a common area would this be ok? 

In the case of a CO alarm it should be near the fuel burning appliance, in the case of a smoke alarm it should be in the general area, and or near the sleeping area.

In the case of a CO alarm ideally it should be vertical near any fuel burning appliance. In the case of a smoke alarm ideally it should be mounted high up (NOT at the top of an apex) on a horizontal plane, vertical is acceptable. In neither case should a detector be left on top of a cupboard or shelf since any rising gas (CO) or smoke particles will carry on past the device.  You may find that "blu tac" will be of use for temporarily securing the device vertically.

You should read the instructions that come with the particular device you have purchased