Quick Answer
Concrete, rebar, Low-E glass and metal cladding are the usual causes of indoor signal loss. Use the material table as a planning range, then confirm the actual loss with an outdoor/indoor measurement.
Typical attenuation by material
The values below are industry ranges for planning only. Thickness, reinforcement, moisture, window area and frequency all change the actual loss.
| Material / structure | Typical loss | Where it matters |
|---|---|---|
| Plasterboard / wood / single glass | 2–5 dB | Interior partitions, small homes |
| Brick / block wall | 5–10 dB | Low-rise residential and commercial walls |
| Reinforced concrete | 15–25 dB | Structural walls, floors, basements |
| Low-E coated glass | 20–30 dB | Office and hotel curtain walls |
| Metal cladding / metal roof | 20–30 dB | Factories, warehouses, cold stores |
| Basement / elevator shaft | No usable path | Underground floors, lift cars |
How to use the table
Start with the outdoor RSRP. Subtract the estimated loss of the main wall or roof between the outdoor point and the indoor point. If the result is close to the usable threshold, a standard booster may work; if it falls far below, plan more antennas, a better donor position or a different approach.
Use the table to ask better questions, not to skip measurement. Two buildings with the same wall material can behave differently because of window area, floor slabs and the direction of the nearest base station.
For a multi-floor building, treat each floor and each wing separately. A single average loss number rarely describes a whole building.
What to do when the loss is high
If the building shell is the main problem, the answer is usually a well-planned indoor distribution system: a donor antenna in the best outdoor position, a booster sized for the antenna count, and service antennas placed by floor or zone. If the outdoor signal is also weak, improve the donor side first with a higher-gain directional antenna, a better mounting height and a shorter, lower-loss feeder.
Do not specify a larger amplifier just because the wall is thick. Amplifier gain cannot recover a signal that is not present at the donor antenna, and excessive gain increases isolation and interference risk.
Book a remote diagnosis
Share the site conditions and we will reply with a preliminary assessment and the measurements still needed.
Frequently Asked Questions
Is Low-E glass worse than concrete?
They can be similar. Low-E coatings commonly cost 20–30 dB, while reinforced concrete is often 15–25 dB. The actual result depends on the coating, glass assembly, wall thickness and frequency.
Can I estimate coverage from the table alone?
No. The table gives an order of magnitude, not a design. A remote assessment also needs the outdoor level, floor plan, antenna positions and target bands.
What if the outdoor signal is strong but one room is still dead?
That usually points to a local shield such as a concrete core, metal plant room or Low-E partition. A small zoned indoor antenna or a dedicated service antenna for that area is often enough, but confirm the indoor RSRP first.