INSULATION - ADVICE NEEDED

My daughters room lies over our garage which is a straight through space that I have not been able to windproof. There is no insulation in her floor, and as a result her room is very cold.

I have been advised tyo use superquilt on the garage ceiling, and would like to knowe idf this really is the answer. can anyone advise me please?

Alternatives would be:

1. Use celotex, but how would I fix it to the garage ceiling?
2. Take the floor up in my daughters room, insulate the floor space, and re-lay the floor. But this will be very time consuming and perhaps just as expensive.

If I use either celotex or superquilt, should I cover them with more plaster board or a plastic sheet to provide another form of protection?

I would be grateful for any advice.

Thanks

I had the same problem with my sons bedroom being over the garage. I took up the floor boards and put in a good 8 inches of insulation. I also added more insulation above his bedroom. I have to say it didn't make a great deal of difference and was still the coldest room in the house.

We converted the garage to a room two years ago and his room was transformed into a cosy corner.

Kingspan is another option, but I think it's a tad pricey!!

How about a suspended insulation ceiling under the garage ceiling