What thickness of insulation do I need between the ground floor ceiling and upstairs floor?

Question

It is a 2 story house and am having an extension but doing all the internals myself.

Answer 1

you dont need any, its optional

Answer 2

You only need insulation between floors if the upstairs and downstairs are independantly heated and cooled. Sometimes homes have a separate AC system for the upstairs because they may not be occupied or used frequently. If this is the case, then you can save on energy by insulating between floors, and allowing either the upstairs or downstairs to get hot or cold as the outside temperature dictates. But if you plan to keep the upstairs at the same temperature as the downstairs, then there is no driving force for energy loss, and you would do better to put the extra insulation in the attic space.

Answer 3

The average 2nd floor use is a 2x12 depending on the span of the room plus the 3/4 in. decking. is the ceiling below over a garage? if so the drywall should be 2 layers thick for firewall codes. the 2x12s are now from 11 1/4 to 11 1/2 wide plus the 3/4 decking plus two thicknesses of 5/8 drywall if needed. You do the math. Why are you asking this anyway?

Answer 4

You don't put any in the interior portion of the house unless you are doing it for sound deadening purposes. It normally only goes on the exterior walls, below the ground floor if you have a crawl space, and in the attic/roof because those are the only places you lose heat or gain heat in your home. To put it in the interior walls or between the first and second floor in some regards is a bad move because it can keep the house from heating and cooling as evenly. So you'll end up having warm rooms and cold rooms because the rooms are insulated from each other and not as easily able to transfer heat between the them.

Answer 5

Unless you are doing it for sound proofing purposes, you don't need any at all because both floors are heated spaces. If your are trying to insulate a basement or crawl space from the house, you would use a minimum of R-19 which is 6-1/4 inches thick. It should be thicker if you live a cold climate.

Answer 6

It is optional but it is not generally done because heat will rise and warm upstairs rooms for very little heat loss as long as loft and wall are well insulated

Answer 7

If it was me I wouldn,t Put any insulation in, nothing to stop you except for the fact that heat rises , and you could find yourself paying more in central heating bills because your heat would not rise due to the insulation stopping it. Just a thought.

Answer 8

There is no need for insulation between floors. The exterior (walls, bottom floor and attic) should be insulated.

Answer 9

are you doing this for sound dampening or heat loss? If heat loss, you should change the flow to your ducts so you don't need insulation between floors.

If sound dampening, you could fit R-30 if you have 2x10. R-38 if you have 2x12.

Answer 10

you dont need any between floors, only in the loft to avoid heat loss to the outside.

Answer 11

insulation causts a few bob. so as much as you can will keep the heat in. so loads and loads. keeps bills down