In short:
- Sandton's outside locks face dry, dusty winters, summer thunderstorms with heavy rain and sometimes hail, and strong high-altitude sun. Each affects locks and finishes differently.
- Most outside lock care is cleaning and checking: keep dirt out of keyways and off bolts and keeps, use a damp cloth and mild detergent on handles, and keep cleaning fluids out of the lock.
- Lubricate only as the maker of your lock says. Makers disagree: some recommend graphite for cylinders, others forbid it, and multipoint makers usually specify grease at set points.
- Use multipoint doors regularly, don't force a stiff handle or key, and have a door that has dropped or swollen adjusted before it damages the lock.
What the local climate does to outside locks
Johannesburg, including Sandton, sits on the Highveld at roughly 1,750 m above sea level and has what climatologists call a subtropical highland climate. It isn't a coastal climate, so salt spray isn't the main concern. The exposures that matter for outside locks are different, and they change with the seasons.
| Exposure | When | What it can do to a lock |
|---|---|---|
| Dry air and dust | Winter and early spring. At O.R. Tambo, July averages under 2 mm of rain (1991–2020 normals). | Fine dust settles in keyways and on bolts, latches and keeps. Mixed with too much lubricant it forms a gritty paste that makes keys rough and stiff. |
| Wind-blown grit | Dry, windy spells in late winter (often called the "August winds" on the Highveld) | Grit is driven into exposed keyways and the gaps around doors, where it wears moving parts. |
| Thunderstorms and heavy rain | Summer, roughly October to April. Afternoon storms are common from November to March, and most of the year's roughly 700 mm of rain falls in summer. | Rain driven against exposed doors gets into keyways and lock cases and washes dirt in with it. Wet timber doors can swell and pull the lock out of line with the frame. |
| Hail and strong gusts | Severe storms, which the South African Weather Service warns can bring hail, strong winds, heavy rain and lightning | Hail can dent or chip exposed handles and finishes. Gusts can slam doors, which strains latches and keeps. |
| Strong sun and UV | All year; winter is the sunniest season, and summer UV can be extreme at this altitude | Fades and chalks coated finishes and can dry out door seals and paint around the lock. |
| Cold nights | Winter; frost occurs occasionally | Rarely a problem on its own, but any moisture trapped in a dirty lock can make it feel stiff on a cold morning. |
ASSA ABLOY's product care guidance for South Africa recommends inspecting and cleaning locks at least once a year, and more often in corrosive environments and "areas prone to atmospheric fallout", which includes dusty conditions. MACO's door-lock manual makes the same point differently: location, weather and environment decide how often maintenance is needed, so fixed intervals can't be set for every door.
Where outside doors take the most punishment
Not every outside door is equally exposed. Doors with no roof overhang or covered stoep, doors facing the direction storms usually arrive from, garden and patio doors, and side doors used by staff or for deliveries tend to need attention first. On each door, the exposure is concentrated in a few places:
Routine care by lock type
Lubricants are where most well-meant maintenance goes wrong, because lock makers give different, sometimes opposite, instructions:
- ASSA ABLOY's South African care guidance says to remove dirt from around the end of the cylinder, then apply a small amount of graphite powder to the key blade and insert it, at least once a year or when the key feels rough. For exposed moving parts it suggests a small amount of Teflon-based lubricant or light mineral oil, and warns against silicone-based lubricants and against using too much, which makes dust stick.
- Gainsborough says not to use oil or aerosol lubricant in its cylinders, and allows a little graphite on the key if it becomes sticky. It also notes that a dusty environment can affect the factory lubricant.
- BASI, a German cylinder maker, tells owners not to lubricate its cylinders with graphite at all, and to use its own care product instead.
- MACO's multipoint door-lock manual says to restore grease at the marked lubrication points after cleaning, using an amount about the size of a pinhead, and then to operate the hardware several times to spread it.
So there is no single right product. Look for the maker's name on the faceplate or cylinder, follow that maker's instructions, and if you can't identify the lock, ask a locksmith rather than guessing.
| Lock type | Safe routine checks | Maintenance to follow the maker on |
|---|---|---|
| Cylinder locks (euro-profile, oval, rim) | Key goes in and turns smoothly; no grit visible in the keyway; cylinder face clean and not loose | Whether to use graphite, a specific spray or nothing in the cylinder |
| Lever mortice locks | Bolt and latch move freely with the door open; strike plate clean, tight and not showing heavy rub marks | What, if anything, to apply to the bolt and latch |
| Multipoint locks | Handle lifts without force; every hook or bolt meets its keep; door closes against the seals without slamming | Grease at the lubrication points; checking fixing screws and adjusting locking points (MACO lists adjustment as specialist work) |
| All outside doors | Hinges tight; door not dropping or rubbing; no water pooling at the bottom of the door or in the lock area | Door adjustment, which is a job for a professional if the lock no longer lines up |
MACO also recommends operating multipoint hardware at least once a month to prevent what it calls "dormant wear". That's worth remembering for patio doors or side doors that are left locked through winter.
Looking after handles, escutcheons and finishes
Handles and the plates around keyholes take the full force of the sun and whatever cleaning products are used on them. Most damage to finishes comes from cleaning, not weather.
- General cleaning: ASSA ABLOY recommends a dilute solution of mild liquid detergent in warm water, a soft brush, and rinsing with fresh water. Gainsborough suggests wiping door hardware with a soft, damp cloth every couple of months. Keep cleaning fluids out of the lock and cylinder.
- Lacquered brass: metal polishes strip the protective lacquer, after which the brass needs constant polishing. Use a damp cloth and mild detergent. Gainsborough warns against abrasive cleaners on coated brass, including lemon juice and vinegar.
- Chrome, gold-tone and other soft or plated finishes: ASSA ABLOY says dirt mustn't be allowed to build up on these, as it discolours and damages the surface. Wipe dust off regularly, especially through dry, dusty months.
- Stainless steel: don't use steel wool or steel brushes; Gainsborough notes they leave particles that can corrode the steel.
- Powder-coated and painted finishes: ASSA ABLOY notes that some change in colour, gloss or chalking may be expected depending on exposure. That's normal ageing in strong sun, not a lock fault.
- Water source: ASSA ABLOY doesn't recommend bore water for cleaning because its minerals can stain coatings.
- Timing: MACO advises against cleaning door surfaces in direct sunlight.
After a storm or a dusty spell
A quick, safe check after heavy weather can catch problems before they leave you locked out or unable to lock up:
- Wipe water and grit off the handle, cylinder face and the strike or keeps with a soft cloth.
- Open the door and operate the lock with the key and handle while the door is open. Then try it closed. If it's smooth open but stiff closed, the door or frame has probably moved or swollen; see why a door locks when open but not when closed.
- If the key feels gritty, don't keep working it in and out. Grit can be pushed further in. Stop and follow the maker's instructions, or ask a locksmith.
- Check exposed hardware for hail dents, chips in the finish, or a handle that no longer springs back.
- Make sure the door can't be slammed by the wind while it's open.
What makes things worse
- Spraying general-purpose oil into a dusty lock. Wet lubricant holds dust and grit, and some makers specifically exclude oil, graphite or silicone. Follow your lock maker.
- Using too much of any lubricant. ASSA ABLOY warns that excess lubricant makes dust stick to parts, which can shorten their life.
- Hosing or pressure-washing around the lock. Cleaning fluids and water shouldn't be forced into the lock or cylinder.
- Abrasive pads, metal polish or strong solvents on hardware. They strip lacquer and coatings that protect the metal.
- Forcing a stiff key or handle. That is how keys snap and multipoint gearboxes break. MACO's manual says excessive force on the handle damages the handle or the lock mechanism.
- Taking the lock apart. Some lock cases are factory-greased and adjusted, and small parts are easily lost.
When to call a professional, and what to send
Call a locksmith if a lock stays stiff after cleaning, if the key is getting harder to turn, if a multipoint handle needs real force to lift, if water has got into a lock that now won't work, if the finish or handle is damaged enough to affect how it works, or if part of a key breaks off. Our guide to a stiff door lock goes deeper into diagnosing stiffness, and our lock repair service covers cleaning, adjustment and part replacement on site. If the lock is too worn or damaged to be worth repairing, see lock replacement.
To help a technician prepare, send:
- A photo of the door from outside, showing how exposed it is (overhang, direction it faces if you know it).
- A close-up of the faceplate on the door edge so the brand and model can be read.
- A close-up of the keyway, handle and escutcheon, and of the strike or keeps on the frame.
- What the door is made of, and whether the problem is worse after rain, on hot afternoons or in dusty, windy weather.
- Anything that has already been sprayed or applied to the lock.
A mobile locksmith in Sandton can then look at the lock, the door and the frame together on site, which is usually where weather-related problems are found.
Questions
How often should outside locks be maintained?
Follow your lock maker's interval. As a general guide, ASSA ABLOY's South African care guidance recommends inspection and cleaning at least once a year, more often in dusty or corrosive conditions, and MACO recommends an annual check of multipoint door hardware and operating it at least monthly. Exposed doors may need attention more often.
What's the right lubricant for my outside lock?
The one your lock's maker specifies. Makers disagree: some recommend graphite for cylinders, others forbid graphite or oil and sell their own products, and multipoint makers usually specify grease at particular points. If you can't identify the lock, ask a locksmith before applying anything.
Does a lock rated for corrosion resistance help on an exposed door?
It can. The European cylinder standard EN 1303 includes a digit for corrosion resistance and temperature, and the lock standard EN 12209 includes a corrosion-resistance grade, so a lock's classification shows how it was tested. That doesn't remove the need for cleaning and the right lubricant. See choosing a replacement lock if you're replacing one.
Need a locksmith to look at it?
If this hasn't solved the problem, our lock repairs service covers it. We're a mobile locksmith in Sandton, so we come to your door.
Sources and further reading
- Wikipedia: Johannesburg (Climate section and 1991–2020 climate table) — Subtropical highland climate at about 1,753 m; summer thunderstorms; dry, sunny winters; extreme summer UV; occasional frost; monthly rainfall
- Mail & Guardian: It's the season for thunderstorms, says SA Weather Service (17 November 2023) — SAWS on Johannesburg hailstorms and storms bringing hail, strong winds, heavy rain and lightning
- Ridge Times: How to combat August winds (8 August 2018) — The Highveld's August winds lifting dust and dirt
- ASSA ABLOY South Africa: Product Care and Maintenance (PDF) — Annual inspection, shorter intervals for atmospheric fallout, cleaning method, finishes, graphite on the key, no silicone lubricants, excess lubricant attracts dust, bore water
- MACO: Operating and maintenance instructions for door locks, end users (Doc. 757585) — Environment decides maintenance intervals, avoid permanent wetness, restore grease after cleaning, monthly operation, annual checks, specialist adjustment
- Gainsborough Hardware: Care and maintenance — No oil or aerosol in the cylinder; dusty environments affect lubricant; stainless steel and coated brass care
- BASI: Fitting and care advice for locking system cylinders — A cylinder maker that says not to lubricate its cylinders with graphite
- ASSA ABLOY DACH: Technical requirements, DIN EN 1303 (PDF) — EN 1303 corrosion resistance and temperature digit
- Union: EN 12209 — EN 12209 corrosion-resistance digit for locks and latches