Will a baby monitor work through a chimney breast?

What is a chimney breast doing to the radio?

A chimney breast is the brick (or stone) column that carries the flues up through the house. In a Victorian or Edwardian terrace it often sits on the party wall, proud of the plaster by a third of a metre or more. The nursery 'alcove' beside it looks like a quiet corner for a cot-side camera. That corner aims the radio through the stack toward the stairs and the kitchen.

Angelcare's UK interference page ranks materials: wood and glass pass a signal more easily; brick is the middle; concrete is harder; metal is the main offender. A lined flue, a damper, a stove pipe or a radiator on the breast adds metal inside that masonry. Babysense lists any large metal object and reinforced concrete as range reducers. BT says large metal items and the building's wall material both cut the indoor figure.

Terrace and Victorian stacks

In a two-up two-down the same stack often runs from the front room, through the back bedroom, and out at the ridge. The cot in the back bedroom can sit in the alcove behind the breast, while you sit in the kitchen on the other side of the same column. That is a short walk and a thick obstacle.

If you also have two storeys of separation, use the two-floor walk-test. The breast and the floors are separate obstacles.

How do I place the cot-side unit around the breast?

Do not try to 'punch through' the stack. Move the cot-side unit so the path goes around it — usually toward the doorway.

1. 1
   Mark the stack Stand in the nursery doorway and note which wall is the breast (thicker, often with a boarded fireplace). The alcove beside it is the worst default camera spot if the stairs are on the other side.
2. 2
   Slide toward the door Keep the unit at cot height, cable out of reach of the cot (Lullaby Trust: control unit out of the baby's reach). Shift it toward the landing until the parent unit on the landing holds a steady picture.
3. 3
   Keep a metre from metal BT: TVs, PCs, routers, microwaves and large metal items at least one metre from both units. Angelcare: do not sit a unit in a window with thin metal strips in the frame — those strips can act as aerials.
4. 4
   Walk the kitchen and the garden door A landing pass is not enough. If the picture dies when you step behind the downstairs breast, move the parent unit to the room side of that breast and repeat.

Metal flues, radiators and window frames

• Flue liner or stove pipe — metal inside the brick. Treat the whole breast as metal-lined, not as a hollow plaster box.
• Radiator on the breast — another metal sheet in the same plane as the camera.
• Metal-framed or leaded window beside the alcove — Angelcare flags thin metal strips in some frames.
• Router on the downstairs mantel — 2.4 GHz noise next to the same stack. Move the router or the parent unit; do not stack them on the fireplace.

Angelcare's AC527 note says the signal strength of the monitor is not something you can boost. Placement around the stack comes before a booster or mesh pack.

Does a longer-range box punch through the stack?

A bigger open-space metre figure assumes line of sight. BT says any obstruction reduces that range significantly; thick stone is named. A chimney breast is an obstruction in the first metre of the path. Buying a longer-range kit without moving the alcove camera repeats the same geometry.

Finish the return-window walk-test with the unit in the doorway position and in the alcove, and keep the notes. The Lullaby Trust's position remains that a monitor is not a substitute for an adult in the same room for the first six months.

In shortA chimney breast is masonry plus, often, metal. Aim around it: cot-side unit toward the doorway, parent unit on the room side of the downstairs breast, one metre from flues and routers. The stack is a placement problem before it is a product problem.