Insulate cellar floor

Basement floor insulation noticeably reduces heat loss and permanently lowers energy costs – for more living comfort, even in old buildings.

Variants for insulating the cellar floor

When renovating old buildings in particular, an insulating material is required that is both lightweight and extremely load-bearing – while noticeably minimizing heat loss. GLAPOR cellular glass gravel is pressure-resistant, rodent-resistant, non-combustible and ensures permanently lower energy costs.

Types of basement floor insulation:

Insulating the basement floor in old buildings:
In old buildings, insulation is usually installed above the existing floor slab. If this is missing or if there is a lot of moisture penetration, it is advisable to replace the floor – for example by installing cellular glass gravel, which combines load transfer and insulation and is also fire, water and pest resistant.
Insulating the basement floor in a new build:
Here, the insulation is planned under the floor slab from the outset. This enables continuous thermal insulation without thermal bridges.

Comparison of floor slab insulation materials

Criterion	GLAPOR cellular glass boards	EPS / XPS / PUR	Mineral fiber insulation
Raw material	✓ 100 % recycled glass	Petroleum-based	Sand & lime (mined)
Water absorption	✓ None (vapor-tight)	Possible through diffusion	Possible
Compressive strength	✓ Up to 1,600 kPa - also suitable for parking decks and flat roofs	Max. 700 kPa, not compression-free	70 -100 kPa, not compression-free
Fire protection class	✓ A1 (non-combustible)	B1-B2 (combustible)	A1
Emissions / leaching	✓ None - emission-free	Waste is dispersed during processing	Fiber dust possible during installation
Disposal	✓ Reusable, urban mining ready, disposal class Z0	Construction waste or hazardous waste	Cumbersome, partly landfillable (with bitumen lamination)
Lifespan	✓ Lifelong - across generations	Characteristics fluctuate when exposed to moisture	Properties change with moisture

Advantages of cellular glass for insulating the basement floor

Cellular glass combines structural stability with ecological compatibility and is particularly suitable for sensitive areas such as basements. Compared to other insulation materials, it has a number of technical and practical advantages:

Non-combustible (building material class A1)
Extremely pressure-resistant up to 1,600 kPa
Dimensionally stable and dimensionally stable
Waterproof
Resistant to rodents and pests
Made from 100% recycled glass
Free from CFCs, HBCD and microplastics
Can be dismantled and recycled

Floor insulation system structure example

The GLAPOR-CEMWOOD combination is the perfect solution for the height differences of up to 80 cm that are typical in old buildings:

GLAPOR cellular glass gravel is ideal for the load-bearing regeneration of sensitive floor structures and offers durable, reliable thermal insulation properties – even for vaulted or capped ceilings.

The Cemwood leveling fill provides a perfectly leveled substrate for further floor construction, and pipes and installations are embedded without any problems.

Innovation: Insulating the floor slab has never been so easy!

GLAPOR RDS combination perimeter system

Plastic-free, waterproof, pressure-resistant. cellular glass boards as certified formwork. Cellular glass gravel as load-bearing thermal insulation. In combination, the healthy basis for every house.

UMB1: Urban mining base plate

The world’s first 100% circular floor slab without concrete made of GLAPOR cellular glass boards. Quickly laid – up to 100 m² per day. Insulates reliably, supports up to 160 t/m² and saves up to 95 % CO₂.

Not sure which product

is the right one for you?

GLAPOR Technology Team

+49 (0) 9633-400769-0
technik@glapor.de

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✔ Customized project consulting

cellular glass 100% made in Germany

✔ 1 00+ million m³ of cellular glass installed

✔ Customized project consulting

cellular glass 100% made in Germany

✔ 100,000,000+ m³ of cellular glass installed

Frequently asked questions (FAQ) about basement floor insulation

FAQ

Is it possible to seal and insulate a basement floor without a floor slab?

Yes, in old buildings with strip foundations, the area between the foundations can be excavated. A capillary-breaking layer, e.g. of cellular glass gravel, can then be laid and combined with pressure-resistant insulation. This construction method provides reliable protection against moisture and improves thermal insulation at the same time.

Which insulation is suitable for the basement floor?

Basically, XPS, mineral wool, PUR and cellular glass can be considered. cellular glass is the most suitable – especially in the case of pressing moisture, high loads or fire protection requirements. It retains its shape, does not store moisture and is completely free of harmful substances.

Should a basement floor be insulated at all?

Yes, absolutely – especially in unheated basements, heat losses often increase due to uninsulated floor surfaces. Insulation reduces these losses, prevents cold surfaces and significantly improves the indoor climate – even on the floors above.

What are the benefits of painting the basement floor?

Painting can be a simple protective measure against surface moisture or abrasion. However, it is no substitute for full insulation – neither in terms of energy efficiency nor building physics.

Which insulation boards are suitable?

The boards must be pressure-resistant, moisture-resistant and – ideally – non-combustible. Cellular glass boards meet all these requirements and are quick and easy to install.