Air tightness

Cellumat cellular concrete, produced at the Valenciennes plant (Nord), has a bright future ahead of it. A building material boasting remarkable airtightness, Cellumat concrete delivers results that far exceed the RT 2012 recommendations.
At the time of COP21 and in the perspective of RT2020, Cellumat's innovative approach reflects its desire to anticipate and respond to environmental emergencies in the sensitive construction sector.

Cellumat uses cutting-edge technologies to produce its entire range of cellular concrete blocks in various sizes. Designed for residential, commercial, and industrial construction, and lighter than conventional concrete, cellular concrete facilitates work on construction sites and saves time and labor. The very structure of cellular concrete gives it unique waterproofing, strength, and insulation qualities, essential for the homes of today and tomorrow. Cellumat cellular concrete allows for ecological, healthy, and sustainable construction.

Strong, durable, insulating, waterproof and easy to install

Using a hollow material in construction creates a greater risk of air leakage than a solid material. Thick joints that are often not watertight, poorly cut or poorly adjusted blocks, poorly placed insulation, grooves that are too deep for ductwork, etc. are all sources of air leaks and therefore "thermal faults."
A remarkable load-bearing and thermal insulator, Cellumat cellular concrete is up to 5 times more insulating than some similar products. The airtightness of cellular concrete blocks is a result of their composition.
A solid material composed of 80% air cells - the best insulator - Cellumat concrete benefits from great qualities of strength, lightness, insulation and airtightness. A Cellumat cellular concrete wall is installed with a thin joint and can be cut perfectly on site. Waterproof by nature, Cellumat cellular concrete therefore requires neither membranes with adhesives nor additional coatings. Since the Cellumat block is a solid block with closed cells, it can be drilled and grooved during construction or even years later without risk to its waterproofing.

Laboratory test:
The airtightness of the Cellumat blocks was tested by the laboratory of the Faculty of Engineering and Architecture in Ghent.
A 50 cm thick Cellumat block wall was installed in a test chamber using Cellucol. And airtightness was measured in accordance with the guidelines of standard NBN EN-12114 in order to study the air permeability of the components and the wall. During this test, carried out on a calibrated test bench and complying with the requirements of standard EN ISO 17025:2005, the watertightness of the wall was studied with and without film coating.
The test results are conclusive, as they show a leakage rate of 0,0957 m3/h.m2 on a wall without film coating and a leakage rate of 0,0009 m3/h.m2 on a wall with a 2 mm film coating. Cellumat cellular concrete therefore achieves airtightness values significantly higher than the standard.

An approach in accordance with RT2012

RT 2012 is, above all, a regulation of objectives and is based on three performance requirements: the energy efficiency of the building, the energy consumption of the building, and summer comfort in non-air-conditioned buildings. And, for these three requirements, the airtightness of the building is essential.

The air permeability of a building characterizes the sensitivity of the building to parasitic airflow caused by leaks in its envelope, or more simply the quantity of air that enters or leaves in an uncontrolled manner through it. It is quantified by the value of the leakage flow rate passing through the envelope under a given pressure difference.

The degree of airtightness determines the thermal performance of the building. The less airtight the building, the more primary energy it consumes to heat it.
Under RT 2012, the treatment of air permeability in residential buildings is mandatory. This treatment can be justified either by a measurement or by adopting a certified approach to the quality of the building's airtightness. The regulatory thresholds are:

- 0,6 m3/h.m2 for individual houses
- 1 m3/h.m2 for collective housing

In order to meet these criteria, air tightness tests are carried out.

Cellumat concrete waterproofing: a proven response
Testing of SIA landlord accommodation in Salomé

Landlord SIA Habitat has completed a project in Salomé, Nord-Pas-de-Calais. This development, consisting of a THPE building and a BBC building with photovoltaic panels, includes 20 housing units and a communal building. The project underwent tests that confirmed the excellence of the Cellumat cellular concrete* blocks, which were used without added insulation.

The aim of these tests was to obtain a sealing result of less than 1m3/h.m2.

In the THPE complex comprising 9 dwellings, 2 tests were carried out in the same dwelling. The conclusions were as follows:

0,34 m3/h.m2, before adjustment of the joinery,
< 0,09 m3/h.m2, after adjustment of the joinery.

In the BBC complex comprising 11 dwellings, 3 of them were tested. The conclusions led to values between 0,4 and 0,7 m3/h.m2.
These excellent results are well below the standard's requirements. This is a benchmark operation for the landlord, who also makes significant savings in materials and labor, since the use of Cellumat concrete made it possible to avoid the need for additional insulation.

* Cellumat Monomur block, thickness 30 cm, λ = 0,09 W/mK

Testing the exemplary site of the Operations Center
roads and forest firefighters in Montreal (07)

A Roads and Forestry Firefighters Operations Center will soon be inaugurated in Montreal, in Ardèche, on a single site.

Covering an area of approximately 1 m500, the offices, garages, and workshops were designed to be in line with the technical nature of the trades they house. The thermal objective for the offices is passive, and for the temperate workshop area, the objective is RT 2.

Atelier Montréal Architecte chose Cellumat cellular concrete for the construction of the passive zone, with a 25 cm wall and exterior insulation.

The airtightness tests - a sensitive point in passive construction - gave remarkable results right from the construction phase on a raw Cellumat wall, without interior finishing coating: the air permeability value under a pressure of 4 PA is 0,083 m3/h.m2, which is well below the 0,15 sought by the project owner, and very far from the 0,6 standard of RT2012. This way, the measurements carried out in the laboratory on Cellumat walls for the airtightness of passive buildings were achieved in real conditions.

Cellumat prepares for the future and RT 2020

Compared to RT2012, the RT2020 recommendations on passive construction raise the bar even higher. RT2020 stipulates that all new homes built from 2020 onwards will be required to be positive energy, meaning they must produce more energy than they consume. To reduce heating and cooling costs, the regulations aim to maximize the energy performance of homes, and the resulting requirements cap primary energy consumption at 15 kWh/m3/year.

For the structural work, three main principles must be taken into account: the quality of thermal and acoustic insulation, the elimination of thermal bridges, and the use of products with very high airtightness. These are qualities that the cellular concrete solutions offered by Cellumat already possess.

Manufacturing with low environmental impact

Cellumat blocks are made exclusively from 100% recyclable natural raw materials. Their production requires little energy.

ISO 14001 certified, Cellumat is committed to continuously improving its manufacturing processes to reduce the environmental impact of its operations. Tested to A+, they generate no dust or particles in the air.

Cellumat develops and manufactures innovative cellular concrete and calcium silicate materials for construction and exterior design.

Cellumat's state-of-the-art plant, located in Valenciennes, incorporates the latest technology. Its annual production capacity of 250 m³ and permanent stock of 000 m³ allow it to respond flexibly to all market demands.