What is it?
Radioactivity is a natural phenomenon in which certain elements spontaneously emit energy. In the field of healthy buildings, assessment focuses on ambient gamma radiation and radon gas, two physical factors covered by the SBM-2024.
Gamma radiation is part of the natural background radiation found across the planet. Radon is a naturally occurring radioactive gas, colourless and odourless, which is produced by the decay of uranium present in some ground and can enter buildings from the subsoil.
Both can be present in the indoor environment as a result of the geological characteristics of the ground, certain building materials and the way the building is constructed and ventilated.
Where can it be found?
Gamma radiation comes mainly from the ground and from some building materials that contain naturally occurring radionuclides.
Radon gas usually gets indoors through cracks, joints, service penetrations, crawl spaces and other points of contact with the ground.
Its presence may be greater in basements, ground floors and poorly ventilated spaces, although every building behaves differently: local geology, the construction system and ventilation conditions have a decisive influence on the levels present.
How does it affect the space?
The levels present indoors depend to a large extent on the building itself: its construction determines how much radon accumulates and the levels of ambient gamma radiation. The behaviour of a property cannot, therefore, be inferred solely from the geology of the ground on which it stands.
Ventilation is part of that equation, together with the construction system and the building’s relationship with the ground.
How is it assessed?
What the inspection looks at
The technical inspection examines how the building is constructed, its relationship with the ground and the ventilation conditions.
What is recorded for each measurement
Equipment, quantity, unit, location, date, measurement conditions and duration, together with the relevant limitations and the interpretation criterion applied.
How this factor is measured
Measurements are taken with specialist professional instruments for gamma radiation and, where appropriate, with equipment designed for assessing radon gas.
Interpretation considers both the results obtained and the behaviour of the building, the intended use of the rooms and the particular conditions of the property.
In assessments intended as expert evidence, calibrated instruments are used to ensure the reliability and traceability of the measurements.
Criteria
Results are interpreted in accordance with the SBM-2024 and, where applicable, taking into account the recommendations and regulations in force for radon gas and natural radiation.
The technical assessment depends not only on the measured value, but also on the geological, construction and functional context of the building.
This guide does not publish values or thresholds. Technical criteria, legal limits and recommendations are different things and are not presented as equivalent.
Improvement measures
Work always begins by understanding and, where possible, reducing the source, before acting on the path or on the space. Measures are prioritised by expected effect, feasibility and proportionality, and no products are recommended by default.
The action taken depends on the origin of the values detected. Options that may be considered include:
- Improving ventilation.
- Sealing radon entry routes.
- Applying specific construction solutions.
- Installing soil depressurisation systems where appropriate.
Each recommendation is made after an individual assessment, weighing technical feasibility and the specific characteristics of the property.
How Cemprotecta helps
This factor is not assessed on its own. It is measured as part of an assessment that treats the space as a system, because the levels depend on the ground, the construction system and how the building is ventilated.
What an assessment gives you is knowing what is there, where it is and what can be done about it, with an ordered sequence of measures rather than a list of problems.
- Inspection of the space and of accessible installations.
- Measurement in the rooms where people spend most time.
- Combined interpretation with the other factors assessed.
- A report with measures ranked by their expected effect on exposure.
Request an assessment
If this factor concerns you in your home or workplace, tell us about your case. The prior inspection will determine whether it is worth measuring and what else should be assessed alongside it.