Frankston granny flat maintenance schedule and costs

The schedule

Printable maintenance checklist, grouped by how often it needs doing

Print it and stick it inside the laundry cupboard door. Ticks are saved in your browser so you can work through it over a weekend. Items marked DIY are safe for a competent owner on the ground. Items marked PRO need a licensed or insured trade, and doing them yourself either voids something or risks a fall.

After every storm

DIY Walk the perimeter and look for ponding water within a metre of the walls. Ponding means the fall has changed.
DIY Clear the overflow relief grate and any surface drain of leaves and bark.
DIY Check downpipe outlets are actually running away, not gurgling back up.
DIY Look up at the ceiling in every room for a new stain, and inside the wardrobe.
PRO After hail or a branch strike, get the roof and flashings inspected before the next rain. Photograph it first for insurance.

Every season, four times a year

DIY Within a kilometre of the bay, hose down the walls, window frames, sills, hinges, door hardware and any sheltered surface rain never reaches.
DIY Clean the bathroom exhaust fan grille and the rangehood filter. A clogged fan is why the corner grows mould.
DIY Wash or vacuum the split system filters. Ten minutes, and it is a warranty condition.
DIY Cut back anything growing within 500mm of a wall, and keep mulch and garden beds below the slab edge weepholes.
DIY Run a finger along the shower silicone. Soft, black or lifting means it is due.
DIY Test the smoke alarm and press the test button on the RCD at the sub-board.

Every year

PRO Clear the gutters, valleys and any box gutter in autumn. $180 to $350, or free if you can do it safely from a stable ladder on level ground.
PRO Timber pest inspection. Annual is the standard interval on the Peninsula and it is the cheapest insurance you will buy: $250 to $450.
DIY Flush the hot water unit relief valve and check for weeping. Two minutes.
DIY Check every external door and window seal, and adjust the strike plates so doors latch without force.
DIY Oil the deck if there is one, and check the fixings on the stairs and handrail.
DIY Photograph the four elevations. A dated photo set every year is how you prove a storm did it, not time.
PRO If tenanted, book the annual smoke alarm check and keep the certificate.

Every few years

PRO Gas safety check and electrical safety check every 2 years if the flat is tenanted. $180 to $350 and $200 to $400.
PRO Re-silicone the shower, bath and vanity at 8 to 10 years. $350 to $750 and it prevents a $3,500 to $9,000 wall repair.
PRO Repaint painted timber cladding at 6 to 8 years coastal, 8 to 12 years inland. $4,500 to $9,500 for a 45 square metre flat.
PRO Camera the ag lines and stormwater every 5 years on a treed block. $350 to $650, and it finds root intrusion before the slab moves.
PRO Service the heat pump hot water unit to the manufacturer interval, usually every 2 to 3 years. $180 to $320.
PRO Inspect and replace corroding fixings, screws and flashings on coastal blocks at around 10 years. Stainless only.

Never do these yourself

Walking on a steel roof, wet or dry. It is slippery, it dents, and dents hold water.
Cutting your own roof penetration for an aerial, a flue or a solar bracket. It voids the roof warranty and it will leak.
Any electrical work at all, including replacing a light fitting. It is illegal in Victoria and it voids insurance.
Pressure washing wall sheets or render at full pressure. It drives water behind the cladding and strips coatings.
Digging along the slab edge without knowing where the services and the ag line run.

What actually wears out a granny flat around Frankston

Salt air. Everything within roughly a kilometre of Port Phillip Bay sits in a marine or benign-marine atmospheric corrosivity zone, and the closer to the water the harsher it gets. Seaford, the Frankston foreshore, Mornington and Mt Martha are all in it. Salt lands on every surface and does nothing until it gets damp, which is every morning. The parts that fail first are never the roof sheets: they are the screws, the hinges, the garage door tracks, the window hardware and the flashings, and the surfaces that rain never washes such as under eaves, behind downpipes and the underside of a carport. Australian practice for coastal steelwork is to specify by corrosivity zone and to wash unwashed areas regularly, and product warranties reflect that.

Soil movement. Frankston City and the Peninsula are a patchwork. Seaford and parts of Carrum Downs are sandy and drain freely. Langwarrin, Skye and much of Frankston South sit on reactive clay classified as moderately to highly reactive under the Australian residential slabs and footings standard. Reactive clay swells in winter and shrinks in a dry February, and a slab edge moves with it. Keeping the moisture even is the whole game: no ponding on one side and a bone-dry garden on the other, no leaking downpipe at a corner, no big thirsty tree planted three metres from a footing. Our drainage page and the site costs page explain what proper drainage costs at build time.

Tree litter. Tea tree, banksia and eucalypt drop constantly rather than seasonally, and a small granny flat roof with a short gutter run fills fast. On the Peninsula we clean gutters that were done ten months ago and find them full.

Condensation. This one is new and catches people out. A 7-star NatHERS dwelling is sealed and insulated far better than the 1970s brick veneer next to it, and a small flat with one or two occupants generates a lot of moisture in a small volume. Without the exhaust fan running properly, moisture condenses on the coldest surface, which is the south wall behind the wardrobe. It looks like a leak and it is not.

UV and westerly wind. West-facing walls and the west end of a deck take the beating here. Expect to repaint or re-oil those first.

The cost of neglect, and the service life you should expect

Blocked gutters for two winters: water backs into the eaves and down the wall. Repairing rotted eaves lining, fascia and paint is $2,800 to $6,500. The clean was $180 to $350.
A collapsed or root-blocked edge drain on reactive clay: uneven moisture, slab edge movement, cracked cornices and doors that will not close. Rectification runs $8,000 to $25,000. Installing the drain properly was $2,800 to $7,500.
Never washing a coastal roof: fixings and flashings fail around year 12 to 15 and take the sheets with them. A re-roof on a 45 to 60 square metre flat is $9,500 to $16,000. The wash-down was about $350 a year, or free with a hose.
Perished shower silicone left for three years: water into the wall frame, swollen skirting, mould. Repair is $3,500 to $9,000. Re-siliconing was $350 to $750.
Termites into an untreated or breached frame: $8,000 to $40,000 and sometimes a rebuild. An annual inspection is $250 to $450.
No ventilation, mould left to establish: $450 to $4,500 depending on how far into the lining it has gone, plus a rental minimum standards problem if it is tenanted.

Realistic service life in this climate

Prepainted steel roof: 30 to 40 years inland, 15 to 25 years within a kilometre of the bay if unwashed.
Colorbond gutters and downpipes: 15 to 25 years, less on a treed block where they sit full of wet litter.
Painted timber cladding: repaint every 6 to 8 years coastal, 8 to 12 inland. Fibre cement with a factory finish: 10 to 15.
Shower silicone: 8 to 10 years. Waterproof membrane behind the tiles: 20 to 25 years if nothing disturbs it.
Heat pump hot water: 10 to 15 years. Split system: 10 to 15 years with filters cleaned.
Treated pine deck: 12 to 18 years. Hardwood deck, oiled: 20 to 25.
Slab and frame: 50 years plus, provided the drainage is maintained. Everything above depends on that.

What voids a manufacturer warranty, and what you can safely skip

Product warranties on roofing, cladding, appliances and coatings are conditional documents, and the conditions are where people lose them. The recurring ones:

Not washing down in a marine environment. Steel product warranties commonly require regular washing of areas not washed by rain. This is the most commonly voided warranty on the Peninsula.
Incompatible metals. Copper or lead runoff onto a zinc-coated or prepainted steel roof will eat it, and so will galvanised fasteners in the wrong sheet. Aerials, flues and old plumbing are the usual culprits.
Pressure washing harder or closer than the maker allows. It drives water behind cladding and strips coating, and the damage looks like product failure but is not covered.
Cutting a termite-treated or preservative-treated frame without re-treating the cut. The cut face is untreated timber.
Owner-made roof penetrations. An aerial bracket or a solar mount screwed through a sheet ends the roof warranty on that sheet and usually leaks within two winters.
Not servicing appliances to the manual. Heat pumps and split systems both have stated service intervals, and a warranty claim will ask for the records.
Sprinklers or bore water hitting steel walls. Repeated wetting with mineral-heavy water stains and corrodes coatings.

The honest bit: what you can skip

Not everything on a maintenance sales sheet is worth paying for. An annual roof inspection on a three-year-old flat is not worth $250 unless something has changed, a storm has been through, or you are about to make an insurance claim. Repainting modern prepainted steel walls before they need it does nothing except cost money and lock you into repainting forever. Sealing a concrete path every year is over-servicing. Anti-mould treatments do not fix a mould problem caused by a fan that never runs.

The four jobs that genuinely pay for themselves are the wash-down, the gutters, the drainage and the silicone, and together they cost under $500 a year to stay on top of. If you do nothing else on this page, do those. If the flat is tenanted, the statutory checks in our landlord rules page are not optional, and keeping the maintenance records is exactly what defeats a wear-and-tear knockback on the insurance page.

Get a price

Get a fixed price for the annual granny flat service

Tell us where you are and what is on the flat, and we will email a fixed-price annual maintenance scope within 3 business days.

Questions owners ask about upkeep

How often should I wash a granny flat roof near the bay?

Within about a kilometre of Port Phillip Bay, hose down the roof, wall sheets, window frames, hinges and any surface that rain does not naturally wash every 3 months. Further inland, twice a year is enough. Plain water and a soft brush is all it takes, and it is the single cheapest thing you can do: a $350 annual wash-down protects a roof that costs $9,500 to $16,000 to replace.

How long should a granny flat roof and cladding last in Frankston?

A prepainted steel roof lasts 30 to 40 years on an inland Frankston or Langwarrin block, but only 15 to 25 years within a kilometre of the bay in Seaford, Frankston beachfront or Mt Martha if it is never washed. Painted timber cladding needs a repaint every 6 to 8 years in coastal air and every 8 to 12 years inland. Shower silicone is an 8 to 10 year item wherever you are.

What does neglecting gutters actually cost?

Frankston blocks are heavy with tea tree and eucalypt litter, so gutters block faster here than in most of Melbourne. Overflow runs back into the eaves and down the wall, and repairing rotted eaves lining, fascia and paint costs $2,800 to $6,500. Clearing the gutters yourself costs nothing and a pro clean is $180 to $350.

Why does drainage matter so much on clay soil?

Much of Langwarrin, Skye and Frankston South sits on reactive clay that swells when wet and shrinks when dry, which moves a slab edge up and down through the year. Keeping soil moisture even around the perimeter is what stops that movement cracking walls and jamming doors. Rectifying a failed edge drain and the resulting movement costs $8,000 to $25,000, against $2,800 to $7,500 to install proper drainage in the first place.

What voids a manufacturer warranty on a granny flat?

The common ones are never washing down prepainted steel in a marine environment, putting incompatible metals in contact such as copper or lead runoff onto a zinc-coated roof, pressure washing a coating harder or closer than the maker allows, cutting a treated frame without re-treating the cut, cutting your own roof penetrations for an aerial or a flue, and not servicing a heat pump or split system to the manual. Each of those is a documented exclusion in most product warranties.

What maintenance can I skip?

Annual roof inspections on a 3 year old flat are not worth $250 unless something has changed. Repainting a modern prepainted steel wall early does nothing, and sealing a concrete path every year is over-servicing. The jobs that genuinely repay themselves are the wash-down, the gutters, the drainage and the shower silicone, which together cost under $500 a year to keep on top of.

How to make your Frankston granny flat last twice as long: the maintenance schedule