Concealed Door Position Sensor Installation in Houston, TX 77019

Recessed or surface-mounted: the decision that sets the whole job

There are two ways to put a contact on a door, and in this part of Houston the choice is made on appearance at least as often as on engineering.

Recessed. A cylindrical switch is set into a bore in the edge of the door stile, and a matching magnet into the jamb directly opposite — commonly a three-quarter-inch bore, with smaller mini versions for slimmer stiles. Closed, the door shows nothing at all. It is the only contact that disappears completely, which is why it is what we fit on a front entry anyone will look at. It also demands the most: a stile wide enough to bore without breaking into the lock mortise, a bore that runs true rather than wandering, and the two halves aligned closely enough that normal seasonal movement does not walk them out of range.

Surface. A small block on the jamb, a matching magnet on the door face, fixed with two screws. Nothing is cut into the door, the whole thing reverses with a screwdriver and a dab of filler, and it tolerates far more misalignment. On a painted jamb, mounted on the stop face where the closed door hides it, a surface contact is much less visible than people expect.

The default in a 77019 house is recessed on the doors you see and surface on the doors you do not — service entries, garage side doors, the back stair.

Boring a ninety-year-old door, and the doors we refuse to bore

River Oaks and the older Montrose blocks are full of original solid-timber doors: heavy oak and mahogany slabs, often with leaded or bevelled glazing, hung in frames that were mortised by hand. Boring one is entirely possible and frequently the right answer, but only after checking what is already inside it.

• The lock mortise. An old mortise lock case can occupy a startling amount of the stile. The contact bore has to clear it vertically, which usually means going high on the stile, near the top corner where the travel is greatest anyway.
• Panel joinery. Rails and panels are not solid through; a bore into a panel field instead of a stile blows out the back face.
• Irreplaceable doors. If a door is original, carved or otherwise not replaceable, we surface-mount, or we put the switch in the jamb alone and take the magnet on a small bracket at the top rail. Nothing is worth boring a door you cannot buy again.
• Labelled fire doors. Unit entry doors in a condominium, and many garage-to-house doors, carry a fire rating label. Field modification outside the manufacturer’s listed preparation can void that label, so we do not bore them. Those get a surface contact, or a concealed contact placed in the frame head where no modification of the door leaf is required.

Getting two conductors through plaster, lath and a pier-and-beam crawl

Pre-war construction here is three-coat plaster on wood lath, and it behaves nothing like drywall. It does not take a rotary cut-out tool cleanly, it cracks well beyond the cut if you force it, and the repair is a plasterer rather than a tub of compound. The working rule is to avoid opening a wall at all.

• Go underneath. Most original 77019 houses are pier-and-beam, and that crawl space is a genuine advantage — a run can come up through the floor plate immediately beside the jamb and into the casing with one small hole in a place nobody looks.
• Use the casing and the baseboard. Tall period baseboards and deep door casings hide a run behind the shoe or in the casing rebate, with no plaster touched anywhere.
• Leave legacy wiring alone. Where remnants of old knob-and-tube or cloth-insulated branch circuits are still present, we do not share a bore, a cavity or a staple line with them.

French doors, sliders and the openings that never sit still

The doors that generate the most nuisance faults in this ZIP are the ones with two leaves and a long history of humidity.

French pairs. Both leaves need watching. A contact on the active leaf alone leaves the inactive leaf — held only by flush bolts into the head and threshold — as an unmonitored opening, and flush bolts are the first thing that gets left retracted. We fit the active leaf at the latch edge and the inactive leaf at the head, so the pair reports independently.

Seasonal movement. Timber doors in a humid Gulf climate swell and shrink measurably between February and August. A recessed contact set to its minimum working gap in winter will start dropping out in late summer. On any solid-timber pair we deliberately choose a contact with gap to spare, or step up to a wide-gap unit, rather than tuning to the tightest setting that works on the day.

Sliding patio doors. The panel moves parallel to the frame, so the magnet slides past rather than pulling away, and alignment in the plane of travel matters more than the air gap. Wanting to distinguish closed from cracked-for-ventilation means two sensed positions: a single reed reports one threshold, not a place along the track.

Condominium and mid-rise work along Allen Parkway and West Dallas

A large share of 77019 is not houses at all — it is the residential towers and mid-rises along Allen Parkway, West Dallas and the Montrose edge. The technical work is smaller there and the coordination is bigger.

• Building approval and insurance. Most buildings require a certificate of insurance naming the association and the management company before a contractor badges in. We carry it; it just needs requesting a few days ahead.
• Service elevator and access windows. Loading dock and freight elevator time is booked, and some buildings restrict contractor work to weekday business hours.
• Nothing happens in the common corridor. Corridor-side drilling, surface raceway in a public hallway and anything mounted on the outside face of a unit door is the association’s decision, not ours or yours.
• The unit entry is a fire door. See above — surface contact or a frame-side concealed unit, never a bore into the leaf.

The openings that matter more here than the front door does

On a well-secured 77019 property the front entry is rarely the interesting one. The contacts that earn their place are usually interior:

• The wine room. A held-open cellar door is a temperature problem before it is a security one, and a contact gives you both an intrusion zone and a straightforward left-open alert.
• A safe room, closet or store room, where the point is not perimeter detection but knowing that a specific interior door was opened while the house was occupied.
• Driveway and courtyard gates, which on the narrower lots here sit close to the street and get pushed open far more often than people assume.
• Service stair and back hall doors, common in larger period houses and almost never covered by the original system.

One honest limit: a contact reports that an opening changed state. It does not secure anything, it does not identify who opened it, and it is not a substitute for a lock. If you want a door to be controlled rather than merely watched, that is access control, and the contact becomes one input to it.

What we do on the appointment, and what drives the number

Every estimate is free, on site and itemised, and we do not quote a dollar figure for this work by phone — the same request can mean one surface contact or eight recessed contacts and a plaster-free route through a period house.

1. Look at each door with you and agree recessed or surface before anything else is decided.
2. Check stile width, lock mortise position and glazing on every door proposed for a bore.
3. Identify the wire path from below or through casing, and confirm the crawl space is workable.
4. Confirm the panel: capacity, whether the zones are supervised, and at what value.
5. Install, with the switch always on the fixed jamb side and the magnet on the moving leaf, so no cable ever crosses the hinge gap.
6. Set the gap with seasonal margin, then test each door closed, cracked and open.
7. Name the zones for the room, not the terminal number, and show you the trouble indication.

What moves the price

• Recessed versus surface, and how many doors get which.
• Crawl space access and condition — a tight or wet crawl is slower work.
• Plaster repair, if any wall genuinely has to be opened.
• Building requirements in a mid-rise: insurance documentation, elevator booking and restricted hours.
• Panel capacity and whether an expander is needed.

The three failures we are most often called in to correct

1. A recessed pair set to its limit. It reads perfectly the week it is fitted and starts faulting when the timber moves with the season. The repair is a wider-gap unit or a re-bore, both of which are avoidable at install by leaving margin.
2. The switch on the door instead of the jamb. This forces a cable across the hinge gap, and a conductor that flexes several thousand times a year fails — usually intermittently, which is worse than failing outright.
3. A bore through a mortise pocket or a panel field. On an original door this is not a callback so much as damage, and it is entirely prevented by checking the lock case and the joinery before the drill comes out.

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