Attic insulation

This past winter I purchased an older home and upon surveying the attic I found that the previous owners made no attempt to update the insulation. Meaning; I still have the older insulation that at best resembles big piles of lint.

My question is two-fold. Does the old insulation have to be removed from the attic or can I further insulate over the top, and will I then be able to replace the the old flooring material with either pressboard or plywood?

This is my first house and the first big project I need to tackle so any info would be greatly appreciated. Thanks so much!

 

You can leave the old insulation there in place. It will be terrible dusty and dirty if you try to remove it. Yes, you can put down 5/8" osb or plywood on the floor. Just so you know, probably only 5 out of 100 home owners up date insulation unless it is really needed. Good Luck

 

Thanks Jack!

Since I live in WI, what rating do you recommend for unfaced insulation in this type of application?

 

Since this is going to be in your attic I would say R-19.

 

Natioal code in most area's is R-30 which is still not enough. Some places require R-38 in the attic's. But, if you plan on putting down flooring you will not be able to get these R-Values. Blown in insulation has to be 12" thick to get R-30. Compressing the insulation will also lose its R-Value too. If you do not have to put down flooring it would be best, so now you can blow in another 12" and have R-30 to R-50. This will save you both in winter and summer. Just make sure you are properly ventilated.