Should I do a full attic cleanout or just top off my old insulation?

Central Texas heat is brutal, and that 90s-era loose-fill has likely settled to the point where it’s barely providing an R-20 value. The short answer is that while you don't technically have to suck everything out, doing a full removal is the only way to perform a high-quality **air sealing** job. In a house that age, the bypasses around your light fixtures, plumbing stacks, and top plates are leaking massive amounts of conditioned air directly into the attic. If you just blow more insulation on top, you're essentially putting a thicker sweater over a mesh shirt; the air still moves right through it.

Since you have a water heater and HVAC unit on a platform, that area is a prime candidate for leakage. You don't need to tear the plywood up, but you should definitely use canned foam or acoustic sealant to hit every gap where the platform meets the joists. For the rest of the attic, once it's cleared, you can see every wire penetration and drywall seam. Sealing those spots with fire-rated foam before blowing in new fiberglass or cellulose is what actualy stops the AC from struggling. It’s the difference between a house that stays cool and one that just has an expensive pile of dust in the ceiling. But if the budget is tight, you can compromise. You coud just rake back the old stuff in the most problematic areas—like above the master bathroom or kitchen where there are lots of recessed lights—seal those, and then blow in enought fresh material to reach an **R-49 or R-60** level. Just make sure you install baffles at the soffit vents first. If you bury your intake vents with new insulation, you'll trap moisture and heat, which will cook your shingles and make your cooling bill even worse than it is now. I’d personally lean toward the full extraction if you plan on staying in the house for more than five years. The comfort level change is night and day when you actually stop the air exchange. And since you're in Texas, check with your utility provider; many of them offer significant rebates for attic weatherization and air sealing that can offset the cost of the vacuum service.

I did exactly this in my 94 build last summer. I skipped the proffesional vacuum and just bought a high-powered shop vac with a long hose to clear out the bays around the plumbing drops and electrical runs myself. It was a miserable, dusty weekend, but once I got the old stuff out of the way, I found huge gaps around the chimney and master bath vents that were dumping cold air into the attic. I hit everthing with Great Stuff foam and then just blew R-49 cellulose right over the old mess in the open areas. My electric bill dropped $80 the very next month. If you've got the stomach for the dust, do the spot-cleaning and sealing yourself.

Spot on. If you're doing a full extraction, don't even look at fiberglass. Go straight for Owens Corning Atticat or, better yet, GreenFiber SANCTUARY cellulose. The density of cellulose helps dampen that Central Texas road noise and has a better R-value per inch when it gets 100+ degrees out. While you've got it cleared, check your recessed lights. If they aren't IC-rated, swap them for some HALO LED retrofits before you seal them up. I did a full suck-out on a '92 build last July and dropped my peak summer bill by $140 a month. Don't forget the Attic Tent for that pull-down stair—it's the biggest leak in the house.

Quick update—I decided to go for the full removal. You guys were right about the air sealing; once the old stuff was gone, I found huge gaps around the plumbing drops. I ended up blowing in that GreenFiber cellulose and the difference is massive. The house is actually staying cool now despite the heat. Thanks for the solid advice!