jpwyatt

I live in a 2 story home that I purchased about 5 years ago in Florida that was built about 15 years ago. I was recently in the attic area and noticed it has blown in insulation that has settled to about 4 to 5 inches thick, not much higher than the 2X4 trusses. Would it be worth the investment to blow in another 10" on top of existing insulation? What should the minimum thickness be?

Griffin

I dont really know what the climate there is like but I would say it would definitely be worth it. Call an insulation contractor in your area and see what they recommend, and ask if they know of any rebate programs, sometimes power or gas companies will give you a percentage of the cost of the installation back, and these rebates usually stack with any state/federal insulation credits there are.

SteelToeS

Hey jpwyatt,

My name is George
Having said that your insulation have settled down i think you probably have a cellulose insulation, pay attention to the color if it is grayish looking then it's cellulose.
Four inches of settled down cellulose equals out to value of R13 ...so yes you should add more insulation to achieve a minimum of R30 in your attic.
I have attached a link to the manufacturer application coverage chart and for the value of R30 you would need a total of 9.2 inches.

Hope that helps and good luck with your project.

http://www.greenfiber.com/images/technicaldocuments/10132009122723AMPM-6.3-30%20Rev%20C%20INS510LDU%20Fact%20Sheet.pdf

joecaption

When adding more blown in insulation you have to make sure not to blow it out over the soffit vents. The best way is to add foam baffles that go in that area, then add the insulation.
What I like to do is duct tape a length of 3" Sch. 20 PVC pipe to the flexable hose on the blower so I can just stand in the middle of the attic and still reach the soffits.
Lowes and HD both will let you use there blower for free to do this yourself if you just buy at least 10 bags of insulation, two people and some dust masks is all you will need. it's DIY 101.
An average sized house can be done for a few hundred dollars. If you hire it out it will be several $1000.00.
If you know the sq. footage of the attic just read the bag of insulation to figure out how many bags you will need.
The was a federal tax rebate on insulation of 30% of the cost of materials that was suppost to run out 12/31/2010 but I've heard it has been extended, you may want to do a Google search to check on it.