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Julian's Locksmith

Upland, San Bernardino County

Installing a Double Cylinder Deadbolt in Upland

Short answer: A double cylinder deadbolt needs a key on both sides, which stops an intruder from breaking glass and turning a thumbturn. It also means you need a key to leave, so building codes generally don't allow one on a home's required exit door. Julian's Locksmith installs them in Upland where they're allowed and suggests safer options where they're not. Call (951) 903-3193.

Double Cylinder Deadbolt Installation in Upland, CA — Deadbolt installation with reinforced strike plate

Not every door on a property is part of the escape route. A workshop, a detached garage, a pool house or a farm outbuilding in San Bernardino County often has a glass-panel door that tempts break-ins, and a double cylinder deadbolt is a reasonable answer when nobody sleeps inside and a clear exit exists elsewhere. Installation on those doors is straightforward: the same bores, a second cylinder, one key. Julian's Locksmith fits the lock, reinforces the strike and helps you decide where the key lives. We verify ownership before starting and quote first. Call (951) 903-3193.

Double Cylinder Deadbolt Installation in Upland: what to expect

Fitting a double cylinder deadbolt is mostly standard door work with a few extra details. The door needs a 2-1/8-inch bore through the face and a 1-inch bore in the edge, a backset of 2-3/8 or 2-3/4 inches, and a thickness the lock supports, usually 1-3/8 to 1-3/4 inches; thicker doors need an extension kit. The interior cylinder sits farther out than a thumbturn, so we check clearance for curtains, door stops and security screens. Both cylinders are keyed alike, and high-security options from Medeco, Mul-T-Lock or ASSA Abloy add restricted keys that limit copies of the one key everyone depends on. The strike matters just as much: a box strike with 3-inch screws into the framing. We finish by testing from both sides with the key and agreeing where the key will live. If the glass sits too close to the bore or the stile is narrow, we explain the options before we drill, so nothing gets cut that cannot be undone.

What we can do on-site

  • Double cylinder deadbolt installation on glass-panel doors. Wood doors with decorative lites, French doors with wide stiles and doors with small windows near the latch are all candidates. We assess the glass distance, mark and drill with a jig, fit both cylinders and test the throw into the strike. You see the lock work from both sides.
  • Swapping a double cylinder for a single cylinder. If you inherited a double cylinder deadbolt, lost the key or recognized the exit risk, we can replace it with a single-cylinder deadbolt keyed to your house key. The bores are the same, so it's a quick swap, and we'll point out ways to protect the glass instead.
  • Keying, spare keys and the key plan. We key the new cylinders to your existing keyway, such as Kwikset KW1 or Schlage SC1, or to a fresh key. For properties with many doors, a keyed-alike plan saves keys. For high-security options, restricted blanks limit copying of the one key everyone relies on.
  • Thick doors, French doors and narrow stiles. A French door's stile has to hold a hole roughly two inches across plus a latch pocket, with room to spare beside the glass stop. We measure stile width and thickness before quoting. If the stile is too narrow, we say so and suggest a surface-mounted or narrow-stile lock instead.
  • High-security and restricted-key double cylinders. If the key to a keyed-both-sides lock gets copied by a former tenant or contractor, the lock is only as good as that key. A restricted-key cylinder makes copying harder. We can fit one, set up the key card and explain how authorized copies work.

What's different about Upland

In family neighborhoods across Upland, kids, guests and busy mornings make a key-to-exit lock hard to live with. Children can't always find or turn a key, and visiting grandparents have never seen it. For the front and garage-entry doors we recommend single cylinders. A double cylinder can work on a detached garage door or a storage room where nobody needs a quick way out.

Hillside and foothill homes near Upland face wildfire evacuation risk and sometimes steep exterior stairs, so a quick exit matters. Smoke and darkness make the seconds a key hunt takes dangerous. A double cylinder on the main exit is a poor trade. We recommend a standard deadbolt on main exits and keep any keyed-both-sides locks for outbuildings that aren't part of an evacuation route.

Older homes in Upland frequently have wood doors with divided glass panes close to the lock, and some already carry a double cylinder from a previous owner. These doors are often the main exit, so we usually recommend a strong single-cylinder deadbolt and laminated glass in the pane nearest the lock. For a rear door that isn't the main route, a double cylinder can make sense. We check stile width before drilling, since old wood can split.

Common situations

  • A landlord in Upland owns a duplex. After a break-in through a rear door's glass, he asks for double cylinder deadbolts on both back doors. We explain that tenants must be able to leave quickly without a key, and that heavier single-cylinder deadbolts with long-screw strikes address the break-in better. We install those, and he arranges laminated glass for the panes.
  • A family off Campus Avenue has a mudroom door with a window beside the lock that opens to the side yard. The front door is their main exit, and the mudroom is rarely used to leave. After checking, we install a double cylinder deadbolt and hang a labeled key hook on the wall near the door, out of reach from the window and visible to everyone in the house.
  • A 1920s Craftsman near Buffalo Inn on historic Route 66 has a front door with nine small glass panes and a thumbturn deadbolt six inches from the nearest pane. The owner asks for a double cylinder. We explain that this is the home's main exit, so a lock needing a key to leave conflicts with exit guidance. We install a strong single-cylinder deadbolt with a box strike instead, and she calls a glazier about laminated glass for the pane nearest the lock.
  • A bungalow has a brass mail slot cut into the front door about eight inches from the deadbolt's thumbturn. The owner has read that a hooked wire fished through a slot can turn some thumbturns. A double cylinder would solve it but trap the household. We suggest sealing or relocating the slot, using a catch box, or mounting the deadbolt higher, and keep a normal thumbturn on the door.

How the visit works

  1. Talk through the door and the reason. Call (951) 903-3193 and tell us which door it is, what it's made of, where the glass sits and why you want a keyed-both-sides lock. A couple of photos help. We ask whether another exit exists, because that answer shapes everything that follows.
  2. Check exits, glass and the people involved. On site, we look at the door, the glass and the exit routes, and verify ID and proof that you own or live at the property. We decide together whether a double cylinder suits this door. If it doesn't, we explain what to do instead.
  3. Measure, quote and choose the hardware. We measure door thickness, backset and stile width, then pick a deadbolt that fits: standard thickness, a thick-door kit or a narrow-stile alternative. You see grade and finish options and get a quote before any hole is drilled.
  4. Prepare the door. We use a drill jig to cut the face and edge bores square, protecting the glass and finish with tape and padding. If the door is already bored, we clean and check the holes. A crooked bore makes the key bind, so we take care here.
  5. Fit both cylinders, key them and set the strike. The two cylinders are tightened evenly, the bolt is adjusted for the backset and the keying is matched to your existing key or a new one. A heavy strike goes into the jamb, and we check the hinge side, because glass doors often give way at the hinges.
  6. Test the lock and plan the key. We test the lock several times from both sides with the door open and closed. Then we agree on the key plan: where the key hangs inside, out of reach from outside, and who knows where it is. You get spare keys and a short checklist.

What affects the cost

  • Lock grade and brand. The lock itself is the first line of the quote. A solid mid-grade double cylinder suits an outbuilding, while a Grade 1 or restricted-key unit suits a higher-risk entry. We quote the specific model so you can compare it with a different grade.
  • Door prep and thickness. Wood doors with glass panes are slower to drill than a plain slab. The jig, masking and careful bore cutting all add time, though they protect your door. If the stile is too narrow for a standard bore, we discuss a different lock rather than force the fit.
  • Number of doors and scheduling. Costs scale with doors. A single workshop door is a simple job, while four doors across a property with a shared key plan take longer but share the setup. Give us the full list on the first call and we'll quote it as one visit.

Every job gets a clear quote before any work starts. Call (951) 903-3193 with the details and we'll tell you what to expect for your situation in Upland.

Mistakes to avoid

  • Skipping the strike. People focus on the interior cylinder and leave a thin strike held by short screws. A hard kick pops a short-screwed strike out of the jamb, and the double cylinder never gets a chance. Fit a box strike with 3-inch screws into the framing at the same visit.
  • Leaving the key in the lock all day. It feels safe because you can always get out, but a key in the interior cylinder can be turned by anyone who breaks the glass and reaches in. If the key lives in the lock, you've paid for a double cylinder and kept the weakness.
  • Buying a double cylinder deadbolt online without checking the door. The stile may be too narrow, the thickness may be wrong or the glass may leave no room for the bore. Returning a lock is cheaper than repairing a damaged door. Measure first, or have us check before you buy.

What to do before we arrive

  • If you rent, don't swap in a double cylinder without written permission. Many leases restrict lock changes, and landlords carry exit and liability concerns of their own. Ask about reinforcing the strike or protecting the glass instead; those requests usually meet less pushback. Keep any approval letter with your lease.
  • Hang the key where a person leaving can reach it in the dark but a person outside cannot. A hook beside the door, high enough that small children won't play with it, is common. Keep it in the same spot every day. A key tucked in a drawer across the room defeats the safety point.
  • Measure the real distance. Picture an arm reaching through a broken pane and see whether it can touch the thumbturn; if it can't, a double cylinder adds nothing. Measure from the nearest glass edge to the thumbturn, and from the glass to the door's far side. Tell us both numbers when you call.
  • Never leave the key in the interior cylinder as a habit. A hand reaching through broken glass can turn it just like a thumbturn, and you've gained nothing over a single cylinder. If you can't keep the key somewhere else, a double cylinder isn't the right lock for that door.

Reaching Upland

Upland is about 24 miles from our San Bernardino base, roughly 30 minutes in light traffic via Belmont and Palm Avenues to I-215 North, I-15 South at the Devore junction. When you call, you get an arrival estimate based on where the technician is and the traffic at that moment.

Once the evening commute thins out on 16th Street, drive times usually shrink. That makes an evening call before closing a practical option for non-urgent jobs that you couldn't fit into the workday.

About Upland: George Chaffey planned Euclid Avenue as a broad boulevard with a tree-lined median, and a three-mile Bridle Path still runs down its center from Foothill Boulevard to 24th Street.

NeighborhoodsThe Colonies at San Antonio, Central Upland, Upland Hills Estates, North Upland, West Upland near Cable Airport, Foothill Boulevard corridor
ZIP codes91784, 91786
Main routesI-10, SR-210, Foothill Boulevard, Euclid Avenue
From our San Bernardino baseabout 24 miles via Belmont and Palm Avenues to I-215 North, I-15 South at the Devore junction, then SR-210 West (Foothill Freeway) to the Campus Avenue or Mountain Avenue exits; for south Upland and downtown, I-15 South to I-10 West and the Euclid Avenue or Mountain Avenue exits

New or replacement locks in Upland?

Call (951) 903-3193 and tell us which doors and what kind of hardware you have in mind. If you already bought the lock, keep the box handy so we can check it fits the door, and we'll quote the install before any work starts.

Frequently asked questions

Can you rekey a double cylinder deadbolt?

Yes. Both cylinders are pinned to the same key, so we rekey both to your new key. If one cylinder is worn or the key is lost, we can also replace the whole lock. We verify ownership before rekeying and quote first. The job takes only slightly longer than rekeying a single cylinder.

Where should I keep the key?

On a hook or spot near the door, within easy reach for someone leaving but out of reach from outside through a broken pane. Everyone in the household should know it, including older kids. Don't leave it in the lock out of habit, since that lets a reaching hand turn it. Rehearse the exit in the dark once a year.

Can you put a double cylinder deadbolt on my front door?

Usually not, if it's the door your household uses to leave in a fire. As the main exit, a key requirement there is a real hazard. We can address the same weakness with a single-cylinder deadbolt, a heavy strike and a laminated glass or film fix. If your front door isn't a required exit, call and we'll talk it through.

Will my insurance company care?

Policies differ. Some insurers ask about locks, and a key-to-exit lock on a dwelling's main door might raise questions in a claim or at renewal. Call your agent and ask directly before you install. We can't speak for any carrier, so we suggest getting the answer in writing if the lock matters to your coverage.

Is a double cylinder more secure than a single cylinder?

Only against one attack: breaking glass and reaching in to turn the thumbturn. Against kicks, prying, picking or drilling, the bolt, strike and frame decide the outcome, not the cylinder on the inside. If no glass sits within arm's reach of your lock, a good single-cylinder deadbolt with a reinforced strike is just as secure and safer to live with.

Can it be keyed to match my other locks?

Yes, if it's the same brand and keyway, such as Kwikset KW1 or Schlage SC1. We pin both cylinders to your existing key, so one key opens everything. If your locks are different brands, we can match the new lock to one of them or rekey the others to a single key.

How far is Upland from your base?

Upland is about 24 miles from our San Bernardino base, roughly 30 minutes in light traffic. Arrival time depends on traffic and on the job the technician is finishing, so we give you an estimate on the phone before you commit.

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Daily 6:30am–11:30pm