Insulation question - I live in an old (106 years) 3 storey house and I am about to replace the wooden flooring on the top floor - I have roof above this floor. The house is quite cold, more so than normal. Is it advisable to put mineral wool insulation between the floors? Are there any fire safety issues? Since, there are electrical cables for light fittings. Although, I was planning to leave a gap in insulation where light fittings are located. Please advise and many thanks in advance.
If you use rock wool, you should be fine. It will help keep the house warmer, keep the noise between the floors down and, as an added bonus, rock wool usually helps the fire rating.
It is not necessary to insulate between floors, most heat is lost through the attic and walls. If you have the old knob and tube wiring, the National Electric Code prohibits insulation around it, as it increases the temperature of the wire. NEC 394.12(5). If a knowledgeable Home Inspector sees this, you will have to correct it before selling the home.
Insulation in the floor will prevent heat loss from any floors below the insulation .If insulating the floor remember to increase the insulation in the roof space The lights i take it are the down lighter type is so then you will need to leave an air gap around the fitting, if these fittings are not the fire proof type then i would also fit smoke hoods or change these to the fire proof type .The cable etc would pose no problem as long as it is of the correct size and installed correctly .If in doubt call an electrician
