Screed with or without thermal insulation: what are the differences

When talking about floor work, screed is often perceived as a simple technical top coat. However, an essential question arises very early in a project: should we ask a screed with thermal insulation Or a screed without insulation ?

This choice directly influences the interior comfort, heating efficiency and energy performances of the building. In this article, we compare the two configurations to help you understand the real differences, beyond conventional wisdom.

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The real role of a screed in a building

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La screed has the main function of:

• level the ground,
• receive the final coating,
• possibly coat a underfloor heating.

On the other hand, screed is not a thermal insulator. Without an insulating layer underneath, it lets the cold pass to the floor or floor below, which has a direct impact on comfort.

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Screed without thermal insulation: what does it mean

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One screed without thermal insulation is placed directly on the load-bearing slab. This solution may seem sufficient at first glance, but it has several limitations.

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Feeling of cold ground

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Without insulation under the screed, the floor remains in direct contact with a cold mass. This results in:

• one Feeling cold on the ground, even in a heated room,
• reduced thermal comfort, especially barefoot.

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Heat losses

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A significant portion of the heat produced in the home escapes downstairs. The heater needs to work longer to maintain a stable temperature.

Limited heating efficiency

With a screed without insulation, the heating is less efficient:

• the rise in temperature is slower,
• energy is less well valued,
• thermal inertia is poorly controlled.

👉 This configuration may remain acceptable in certain technical rooms or specific projects, but it quickly shows its limits in housing.

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Screed with thermal insulation: a real gain in comfort

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Add a thermal insulation under screed radically changes the behavior of the soil.

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Immediate improvement in comfort

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The insulation creates a barrier between the screed and the cold support:

• The ground is more pleasant to the touch,
• the temperature is more homogeneous in the room,
• the feeling of cold gradually disappears.

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Better energy efficiency

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One screed with thermal insulation limits heat loss:

• the heat stays in the living space,
• the heater works more stably,
• the energy produced is better exploited.

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A major advantage for floor heating

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In the case of a underfloor heating, screed insulation is essential:

• the heat is directed upward,
• the rise in temperature is more rapid,
• the system operates at a lower temperature, with better efficiency.

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Impact on energy savings (not to mention prices)

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Even without entering specific figures, the principle is simple:
👉 less losses = less energy consumed.

One thermally insulated screed allows:

• to reduce heating needs,
• to stabilize the indoor temperature,
• to improve the overall energy performance of the building.

In the long term, this means more rational use of the heating system and better daily comfort.

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In which projects is a screed with thermal insulation essential?

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One thermal insulation under screed is highly recommended when:

• the ground rests on a cold slab or a ventilated void,
• one underfloor heating is planned,
• thermal comfort is a priority,
• the project aims for good energy performance,
• it is a residential unit (house or apartment).

In these situations, a screed without insulation quickly becomes a weak point in the building.

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When can a screed without insulation suffice?

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One screed without thermal insulation may be considered:

• in some technical rooms,
• in unheated spaces,
• when the insulation is already present under the slab,
• in very specific projects where thermal comfort is not an issue.

In all cases, this decision must be taken in full knowledge of the facts, after analyzing the support and use of the building.

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Screed with or without insulation: thinking for the long term

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The choice between insulated screed or non-insulated screed should not be limited to immediate logic. It is an arbitration between:

• daily comfort,
• energy performance,
• sustainability of the building.

One thermal insulation under screed well-designed provides consistent benefit throughout the life of the floor.

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Conclusion: a technical choice that impacts daily comfort

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La screed with thermal insulation offers greater comfort, better heating efficiency and smarter energy management.
La screed without insulation, for its part, remains a one-off solution, adapted to specific cases but limited in the home.

Chez Davide Chape, each project is analyzed according to the existing support, the use of the rooms and the planned heating system. This approach makes it possible to recommend the most consistent solution, without unnecessary oversizing. Contact us now to get a quote.