Increasing Attic insulation over loose fill

[tomstin]

I've been searching the net and could use some help. My house is 6 years old, loose fill insulation in the unfinished attic, the chart says 12.5 inches and R30. 2x8 ceiling rafters and it's roughly 4 inches over that, so it's pretty close. The recommendation is R49 here in NC. And the upstairs gets pretty warm is the summer. The question is, would I gain much by adding batt insulation over to get R49 or greater? I realize I will smash down the loose fill so I will probably loose some R value, but any voids will be filled.

If I go this way, should I put the batts over the HVAC vent hose, or lift them up somehow so they don't crush the batts?

Any online resources anyone has found?

With the price of natural gas these days, the investment will probably be worth it.

Appreciate any insight.

 

[CraigFL]

I've seen batts over loose fill. You could also blow in more loose fill. Places like Home Depot should rent those machines.

 

[Bill K]

Hi another NC junkie here. You will be better off adding more blown insulation rather than batting. Faster ,will cover better, and if you put batts over the blown in it will compress and loose over half or more of it;s R value. Plus you will have gaps in between the batts and you would need to use unfaced over the insulation allready in place. Bill

 

[3G_SDS]

Blown insulation is faster, better, cheaper, and messier. I blow in 78 bags over my orginal R12 batts this spring to make a R80 in my attic. (upstate NY... by the lake, very cold)
but you want free moving air over your insulation, 4-6" atleast.

 

[Wile1Coyote]

I did Batts over blow in in my last house, blown in was below top lip of the ceiling\attic floor joists so I ran the other direction with the batts, I used the 25' long coated rolls and created a nice 2" layer between the batts and the blow in. House was toasty after that!

 

[Chris91LX]

Do you ever have to replace the blown in insulation? My house is over 60 years old and the blown in insulation is pretty dusty/crumbly.

 

[filthy_shovel]

Do you ever have to replace the blown in insulation? My house is over 60 years old and the blown in insulation is pretty dusty/crumbly.

I would not unless my insurance company would demand it. It is not the age of the insulation that matters, but the gaps that have formed with time. Simply fill them in or put more in.