Suggestion for thickness of insulation.

[chaluska]

Hello All, in a house im currently about to buy, the insulation in the attic is "literally" 2-3" thick, and in some spots it looks very loose. loose enough to see the sheetrock cieling above it.

My question, for houston texas summers, which is 100+ for several days at a time, with 100% humidity, how thick should i apply new spray in / blow in insulation?

ive heard of stacking it 12" thick, but my rafters are only 2x6. does that mean the insulation is stacked higher than the rafters? the attic is not used for storage in my home, only to hold the a/c, and run piping.

any advise for a auto-mechanic who is trying to be a home mechanic.

 

[gatorfan]

Yes, lots. Much much more than what will fit in a 5.5" cavity (assuming fiberglass, max insulation that would fit would be R19, but cellulose is better insulation per inch). Attic is the best place you can insulate, so I would put go towards the high end of the gov't recommendation: Recommended Levels of Insulation: ENERGY STAR. 12 inches of cellulose would get you to about R-40 which is in the range in the above link.

Matt