How to insulate attic and walls of house?

Question

OK, never done this, I'm trying to cut down on our huuge heating bill. This house we're in is older, and not built very well. So, were' trying to insulate as much as possible.

The attic has insulation but it's really old, and the inspector said it was rated to some number that wasn't nearly enough. So when I get new insulation, should I get the fiberglass rolls, then just roll it right over top of the old stuff? OR, should I rip the old stuff out??

And whats the best way to insulate the walls? Can I do this by shooting some of that loose stuff down the walls from the attic?

Thanks, I'm totally clueless..

Answer 1

Heat rises, so your first improvement is to insulate the attic.

Unless your existing attic insulation is wet or significantly compacted (then you should remove it), just lay new fiberglass over the existing layer - you will increase the total "R" value of your insulation. For example, if you have 6" of FG in the attic (R value = 16), adding another 8" of FG (R value = 30) will nearly triple the total insulating value. Run the new rolls at right angles to the existing layer of insulation to close off any spots that might leak. Be sure that you do not insulate over recessed ceiling light 'cans' -- unless you know for sure that they are designed for zero clearance to insulation. Typical cans need space for air to circulate.

Contact your electric utility for an energy audit. They can suggest low-cost ideas to cut your heat losses, and they can analyze your home for the most cost-effective insulating projects - double-paned low-e windows, blown-in wall insulation, replacing a low-efficiency furnace, caulking, weatherstripping, etc. And they might offer rebates and/or low interest loans.

Good luck.

Answer 2

If the old insulation is dry and not damaged in any other way, leave it. Roll the new stuff over it.
As for the walls, it is not likely they are open at the top. you would have to drill holes to feed the insulation down into the wall. it is possible if you use the small BB shaped foam. Do it before you insulate the attic so you are not crushing the new stuff.

You can also save a lot by using the plastic sheeting you stretch across windows and shrink with a hairdryer. Those provide a barrier between the house and the cold glass. Cheaper than new windows and much easier/ faster.

The electrical outlets on outside walls leak a lot of cold air. Buy the flat foam sheets that go behind the coverplate, they make a BIG difference.

Answer 3

I helped build a school last year and I can say that the best thing to do is put new fiberglass in there and take out the old ones. Plus, to save on heating bills, make sure all the gaps between the windows and doors are sealed; if not then caulk them in. Those little cracks may not be visible to us, but heat will escape through them. Well, good luck with the insulating!

Answer 4

insulation is rated in R-Value... the norm is:

floors= R-19 ( 6" thick)
walls= R-13 ( 3 1/2" thick)
ceilings= R-30 (9" thick)

if u buy more for the attic, roll it out opposite way the other is rolled out.....across the other insulation...but only if the old insulation is equal or above the ceiling joist...

it has been my experience that u can contract the job done cheaper than u can go buy all the material! calla insulation company for a estimate.....

lc. gen. contractor