August Home Maintenance Checklist: Beat the Fall Booking Rush

August's checklist has two jobs: notice what a summer of heat has done to your house, and get on the calendars of the pros everyone else will call in September. Book your chimney sweep and heating service now, test the sump pump and its backup battery before storm season peaks, finish shrub pruning before the cold-climate cutoff, and take one slow lap around the exterior to catch heat damage while it's still cheap. The hands-on work totals a few hours. The phone calls take twenty minutes and save weeks of waiting.

The summer maintenance guide has the season-long view; below is just August, plus the first pieces of fall prep that reward starting early.

Make the fall service calls now

Every chimney sweep and heating contractor has the same busy season: the six weeks after the first cold night, when everyone remembers their furnace at once. In August, you're calling into an open calendar. In October, you're taking whatever slot is left.

Book the chimney sweep. If you burn wood, the flue needs a certified sweep's cleaning and inspection every year; creosote buildup in the flue is the leading cause of chimney fires. Gas fireplaces need an annual inspection too, per NFPA 211, because condensation in gas exhaust corrodes the flue liner and bird nests can block the vent, backing carbon monoxide into the house. Expect $150–350 for the 1–2 hour visit.

If you have a boiler, schedule its annual service. This one is critical, not a nice-to-have. The technician runs a combustion analysis, inspects the heat exchanger, tests controls, and cleans the unit, typically $150–350 for 1–2 hours, and most manufacturer warranties require it. A cracked heat exchanger leaks carbon monoxide, the kind of problem you want found in a September service visit rather than discovered in January. Cold zones 5–7 should book earliest; heating season there starts a month or more before everyone else's.

If you have radiant floor heat with glycol, have the fluid replaced now if it's due. Glycol degrades even when annual pH checks look fine, and once it turns acidic it corrodes copper tubing and the boiler heat exchanger from the inside. A professional drain-and-refill runs $300–600 and beats the $2,000–5,000+ repair for pinhole leaks in tubing embedded in your floor.

Furnace and heat pump owners aren't off the hook; the tune-up belongs in early fall, and the smart move is booking now for a September or October date. The full year of timing is in our HVAC maintenance schedule.

Test the sump pump before storm season peaks

Late August through September is when the sump pump earns its keep: hurricane remnants in the East and Southeast, the first serious fall rains elsewhere. Test it now, on a dry day.

Pour a 5-gallon bucket of water into the sump pit and watch. The pump should kick on, clear the water, and shut off. That's the whole test, 10–15 minutes and free. If it doesn't run, or runs and won't shut off, call a plumber this week; a failed pump discovered during a heavy rain means a flooded basement and a repair bill in the thousands.

Then test the backup battery, because the storms that flood basements also knock out power, and a sump pump with no electricity is a bucket. Replace any battery over 3 years old or holding a weak charge; they run $100–150. While you're down there, our plumbing maintenance checklist covers the rest of the basement.

Walk the house and look for heat damage

By late August, your house has taken two-plus months of UV, thermal expansion, and thunderstorms. One slow lap around the exterior tells you what that cost, and the fixes (caulking, touch-up paint, minor roof work) want the mild, dry weather of early fall, so look now.

• Caulk and sealant. South- and west-facing joints take the most sun. Check window and door perimeters and anywhere siding meets trim: cracked, chalky, or pulling-away caulk goes on the September list, before fall rain finds the gaps.
• The roof, from the ground. Binoculars are enough. Look for cupped, cracked, or missing shingles after summer storms, and check under the gutters for piles of granules. Roofers book up fast once fall rains start, so chase anything suspicious now. Our roof maintenance guide covers what each symptom means.
• Trees and limbs. Look up as you walk: dead limbs, and any live branches hanging over the roof, driveway, or service line. Routine trimming belongs in the dormant season, when trees tolerate cuts best, so for healthy limbs the August job is spotting them and getting on an arborist's calendar; they book out too. A genuinely dead limb over the house is the exception, worth taking down before storm winds do it for you. Small stuff is a DIY afternoon; anything involving a chainsaw overhead or near a power line is arborist work, full stop.
• The AC, by ear. It's been running hard since June. Warm air, ice on the refrigerant line, or short cycling means a service call now, not a note for spring.

Finish pruning before the window closes

If you're in cold zones 5–7, this is the month that matters: stop all shrub and hedge pruning by September 1, because pruning stimulates tender growth that won't harden off before frost kills it. August is your last comfortable window to shape broadleaf evergreens like boxwood, holly, and privet. Plan on 1–3 hours with hand tools for under $20, or $100–350 for a crew. The cost of letting shrubs go: heavy renovation pruning runs $300–1,000+, and many evergreens (yew, juniper, arborvitae) won't regrow from old wood, so a badly overgrown one gets replaced at $50–200 per plant. Warm zones 1–3 have no hard deadline, though the trimming comes around more often.

While the loppers are out, recheck the clearances from July: 12–18 inches between shrubs and siding, 24–36 inches around the AC condenser. One wet month of growth closes those gaps, and foliage against the house traps the moisture that feeds rot and gives pests a bridge.

Keep the pest sweeps going

Nothing new here, just don't stop early. Keep up July's weekly standing-water patrol; a new generation of mosquitoes hatches roughly every week to ten days from as little water as a bottle cap holds. August is also a scheduled round of the every-other-month tick and flea treatment: hit shaded areas, tall grass edges, and wherever pets rest, 20–30 minutes and $15–40 DIY or $75–200 for a pro. In hot-humid zones 1–2, mosquito checks continue right through fall.

In fire country, this is the critical month

Late summer is the heart of fire season across the hot-dry West, and two tasks are top priority there:

1. Maintain defensible space. The first 5 feet around the structure should be hardscape only: gravel, stone, or concrete, with no plants, mulch, or organic material of any kind. From 5 to 30 feet, thin vegetation, keep tree canopies at least 10 feet apart and off the house, and clear dead material. Budget 3–6 hours DIY or $300–1,500 for a crew. Vegetation inside that first 5 feet is the number-one way homes ignite, homes without defensible space are 2–4 times more likely to be destroyed, and many insurers now require compliance.
2. Clear the roof and gutters of dry debris. Pine needles and leaves in valleys, behind the chimney, and in gutters are ember fuel. An hour or two DIY, or $100–300 for a pro. This is a fire task, separate from drainage-season gutter cleaning.

Common questions

Is August really the right time to book furnace service?

Booking, yes; the visit itself can land in September or early October. An August call gets a convenient early slot; an October call gets a two-week wait during the first cold snap. In zones 5–7, where heating season arrives early, book at the start of the month.

My fireplace is gas. Do I still need a chimney inspection?

Yes, annually, per NFPA 211. Gas exhaust carries moisture that corrodes the flue liner over time, and birds treat uncapped gas vents as nesting spots. Either one can push carbon monoxide back into the house, which is why the inspection stays on the list even with no creosote involved.

How do I know if my sump pump battery is dead?

Test it the same day you bucket-test the pump: most backup systems have a test button, or unplug the primary pump and trigger the float. Any battery over 3 years old is on borrowed time regardless of the test result; replacements run $100–150.

Can I still prune shrubs in late August in a cold climate?

Before September 1 in zones 5–7, yes. After that, pruning pushes tender growth that frost will kill, stressing the plant. Removing dead or broken branches is fine any time of year; it's the shaping cuts that need to stop.

Which of these apply depends on the house: no basement means no sump pump, no fireplace means no sweep, and zone 2A has no pruning deadline. SeasonKeep keeps track of which is which for your address and sends reminders at booking time rather than breakdown time; the free plan is enough to try it. When you're ready to look ahead, the September checklist is where fall prep begins in earnest.