Glossary

Quantity in decibels representing a laboratory measurement. It is the reduction in weighted normalised impact sound pressure level between a basic reference structural element with an additional layer (e.g. floating floor or suspended ceiling) and the basic structural element without this layer (homogeneous concrete slab).

Reference standard: UNI EN ISO 717-2  and UNI EN ISO 10140-3

△L_w,direct = L_n,w,with - L_n,w,without

Quantity in decibels, obtained from the difference between the weighted normalised impact sound pressure level of a generic reference structure with an additional layer (floating floor, finishing layer, partition, or suspended ceiling) and the weighted normalised impact sound pressure level of the same reference structure without this layer.

Refernce standards: UNI EN ISO 717-2  and UNI EN ISO 10140-3

Quantity in decibels representing a laboratory measurement. It is the difference in sound reduction index between a basic reference structural element with an additional layer (e.g. floating floor or suspended ceiling) and the basic structural element without this layer.

Reference standards: UNI EN ISO 717-1  and UNI EN ISO 10140-2

△R_w,direct = R_w,with - R_w,without

Quantity in decibels, represents the difference in sound reduction index between a generic structural element with an additional layer (e.g. floating floor or suspended ceiling) and the basic structural element without this layer.

Reference standards: UNI EN ISO 717-1  and UNI EN ISO 10140-2

Quantity in decibels, representing impact sound insulation of floors, obtained according to the method specified by UNI EN ISO 717-2 from laboratory measurements carried out in accordance with the UNI EN ISO 10140-3 standards for a 10 m² surface sample.

Reference standards: UNI EN ISO 717-2  and UNI EN ISO 10140-3

Quantity in decibels representing impact sound insulation, obtained according to the method specified by UNI EN ISO 717-2 from on-site measurements carried out in accordance with the UNI EN ISO 16283-2 standards for a 10 m² surface sample.

Reference standards: UNI EN ISO 717-2  and UNI EN ISO 16283-2

Quantity in decibels representing airborne sound insulation, obtained according to UNI EN ISO 717-1 from on on-site measurements carried out in accordance with the UNI EN ISO 16283-1 standards.

Referernce standards: UNI EN ISO 717-1  and UNI EN ISO 16283-1

Quantity in decibels representing the airborne sound insulation of a building element, obtained according to the method specified by UNI EN ISO 717-1 based on laboratory measurements carried out in accordance with the UNI EN ISO 10140-2 standards for a 10 m² surface sample.

Reference standards: UNI EN ISO 717-1 and UNI EN ISO 10140-2

Decoupling layer between screed and the substarete, designed to reduce the transmission of vibrations.

Reference standard: UNI 11516

Flexible isolating strip installed between the screed and adjoining vertical building elements, serving as a perimeter expansion joint.

Reference standard: UNI 11516

Layer applied over the screed, either bonded or floating, used as a substrate for the floor covering. It serves multiple functions: waterproofing, decoupling the covering from the screed, acting as a vapor retarder or barrier, allowing lateral vapor diffusion without affecting the screed or floor covering, and improving acoustic insulation.

Reference standard: UNI 11944

Acoustic measurement carried out on site after the building was completed according to UNI EN ISO 16283 series standards.

Reference standard: UNI EN ISO 16283-3.

Acoustic measurement carried out by an official laboratory according to UNI EN ISO 10140 series standards.

Reference standard: UNI EN ISO 10140-3

Measurement of the reduction in normalized impact sound pressure level given by an additional layer carried out on a homogeneous concrete floor in Isolmant laboratory facilities.

Reference standard: UNI EN ISO 16283-3

Spectrum adaptation term to be added to the single-number quantity to take account of the un-weighted impact sound level, representing the typical spectral characteristics of impact noises.

Reference standard: UNI EN ISO 717-2

Spectrum adaptation term to be added to the single-number quantity to take account of spectrum No.1 (pink noise).

Reference standard: UNI EN ISO 717-1

Spectrum adaptation term to be added to the single-number quantity to take account of spectrum No.2 (traffic noise).

Reference standard: UNI EN ISO 717-1

A screed with a consistency that allows the fresh material to naturally spread and form a flat horizontal surface. In the fresh state, it must have at least one of the following characteristics:

• consistency ≥ 220 mm, for UNI EN 13454-2
• flow > 120 mm, for UNI EN 12706

Reference standard: UNI EN 11944

Also known as traditional screed, this product consists of a mixture of components with low water content and binder, having a consistency similar to that of damp/wet sand.

Reference standard: UNI EN 11944

Screed with the appearance of a homogeneous mortar but without the fluidity of a self-leveling screed. Requires mechanical action (troweling) for installation.

Reference standard: UNI EN 11944

Layer of material laid on site, directly on the relevant substrate and either bonded or unbonded to it, or laid over an intermediate layer or insulating layer, with the purpose of achieving one or more of the following objectives:

• to achieve a specified level;
• to receive the final floor covering;
• to serve as a wearing layer.

Reference standard: UNI EN 13318

There is no standardized definition for 'lightweight,' although screeds with a density below 800 kg/m³ are generally considered as such, typically used as leveling layers for installations.

Screed intended to be covered by a floor finishing. It cannot serve as a wearing layer.

Screed whose dry density, after a 28-day drying period, is less than 1,400 kg/m³.

Reference standard: UNI EN 13318

Set of horizontal technical elements of the building system, designed to divide and organize the internal spaces of the building system itself.

Reference standard: UNI 11516

Finishing/wearing layer laid over the screed.

Reference standard: UNI 11516

Layer on which the floor system rests (floor slab, existing flooring, foundation).

Material with non-fluid but thixotropic rheology that requires troweling to be applied in a continuous and homogeneous layer. Generally applied in very thin thicknesses.

Reference standard: UNI 11944

Set of precautions and conditions to be maintained during the period in which the hydration and hardening process of the binders takes place, in order to ensure that the screed achieves the performance levels defined during the design phase.

Reference standard: UNI 11944

Heating/cooling system (see UNI EN 1264-1:2021).

Reference standard UNI 11944

Radiant systems of type A, B, H, I, and J according to UNI EN 1264-1, where the screed thickness above the pipe is less than 15 mm (excluding type B).

Reference standard: UNI 11944

Radiant system of type A or type B according to UNI EN 1264-1, with a minimum screed thickness above the pipe greater than 30 mm.

Reference standard: UNI 11944

Type A, B, H, I, and J radiant heating systems according to UNI EN 1264-1, with a screed thickness above the pipe of less than 30 mm and more than 15 mm (except for type B), whose thermal behavior is comparable to that of a traditional radiant system.

Reference standard: UNI 11944

A technological system designed to limit the transmission of impact noise and airborne sound, consisting of a load-bearing element (screed and surface finish) that is completely separated from the other building components (vertical and horizontal partitions and services) by a decoupling layer (resilient material or perimeter isolation strip).

Reference standard: UNI 11516

A layer designed to provide the horizontal or vertical partition with a defined level of thermal insulation performance.

Reference standard: UNI 11516

A structural element that forms the load-bearing support for the entire floor stratigraphy.

Reference standard: UNI EN 13318

A layer placed above the existing slab/support with the function of insulation and/or lightweighting and/or leveling (without a direct flooring/finish installation function), designed to receive the screed.

Reference standard: UNI EN 11944

Electrical or plumbing connections, including sewer drains, typically contained within or made using PVC pipes, corrugated tubing, or similar solutions.

A finishing strip used to cover the joint between the floor and the base of the vertical partition or wall.

Reference standard: UNI 11516

The top layer of a floor, serving as the wear and finish surface. Examples include ceramic, wood, LVT, linoleum, resin-based systems, etc.

Reference standard: UNI EN 13318