How much insulation is in your attic?
Measure it with a ruler, pick the type, and see your approximate R-value, with what ENERGY STAR’s table lists for the Bay Area.
- Free
- About 1 minute
- Your answers stay on your device
Safety first.
Not comfortable going up? Skip it. We measure it for you at the free inspection.
- Step only on the joistsThe wood framing. Never step on the insulation or between the joists: the ceiling below will not hold you.
- Wear a dust mask and glovesLong sleeves help too. Insulation and dust can irritate skin and lungs.
- Bring a good flashlightAnd watch your head: roofing nails come through the roof boards.
- Skip hot afternoonsAttics get very hot. Go early in the day.
- See droppings? Leave themDon't sweep or vacuum them. Follow the CDC's clean-up steps or let us look at it.
How to measure.
- 1Stand on a joist near the hatchShine the flashlight across the attic floor first, so you see where the joists run.
- 2Push a ruler straight downSlide it gently through the insulation until it touches the ceiling board. Don’t press the insulation flat.
- 3Read the top of the layerRead the inches where the top of the insulation meets the ruler.
- 4Check 3 or 4 spotsInsulation is often thinner in some places. Use the depth you see most.
What ENERGY STAR’s table lists.
Its table for existing homes in climate zone 3, which includes the Bay Area, lists how much insulation to add:
- R49to add in an attic with no insulation
- R38to add when there is already a thin layer (see the table)
- R19for the floor
We measure the insulation you have now and recommend the R-value for your home and the code that applies. Your quote states the R-value we install.
Sources: ENERGY STAR, recommended home insulation R-values · PNNL / U.S. DOE Building America, loose-fill insulation · NAIMA, fiber glass batt R-values and thicknesses
Questions, answered.
Is insulation depth the same as R-value?
No, but they are linked. R-value is how well insulation slows heat. Each type gives a different R-value per inch, so the same depth of loose fiberglass and cellulose gives a different R-value. This check multiplies your depth by an approximate per-inch range for the type you pick.
What do ENERGY STAR’s attic numbers mean?
Its table for adding insulation to existing homes in climate zone 3, which includes the Bay Area, is about how much to add: R49 for an attic with no insulation, and R38 when there is already a thin layer. It does not grade the insulation you have now. See ENERGY STAR, recommended home insulation R-values.
Do I have to go into my attic?
No. At the free inspection we measure the insulation you have now and recommend the R-value for your home and the code that applies. Your quote states the R-value we install.
Is depth the only thing that matters?
No. An even layer with no gaps matters as much as the number. Insulation that is soiled by rodents, wet, flattened or pushed aside also works less well.
Want it measured for you?
Book a free inspection. We check your attic, crawl space and garage, and you get a written quote, usually 30–60 minutes after the inspection, same day at the latest. Please be home for the inspection.
$300 off any job over $2,000, or 10% off for seniors, expecting moms, veterans or multiple services. One discount per job.