Roofs
Pitched roof insulation
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High-pitched Roofs with Intermediate Rafter Insulation In terms of acoustic engineering, high-pitched roofs represent light double partition constructions. Both shells are externally formed by roof cladding as well as possibly existing roof boarding and inside by room-facing rafter cladding. Additionally installed water vapor retarders and/or underlay foils can enhance acoustic tightness of the roof but that would normally not lead to higher weighted sound damp measurement since the roof?s acoustic properties are not influenced in the low-frequency range. The rafters produce a mechanical link between both shells. |
Influence of Filling Factor on Sound Insulation of High-pitched Roofs with Intermediate Rafter Damping |
Sound Transmission Paths
Sound waves impinging upon the roof pane externally are on the one hand transferred to the interior to be protected by direct sound passage in the rafter area. Transmission of structure-borne sound over the rafters limits the level of max. attainable damping measurement. Moreover, sound waves may penetrate into the rafter interspace through roof membrane leakiness. Sound-absorbing Isover mineral wool insulants effectively dampen the rafter interspace, and above that reduce the influence of holes and slots in the external roof membrane that cannot be avoided while roofing with pantiles. The higher dimensioning of insulating thickness the higher the sound-absorbing effects of mineral wool and thus sound damp measurement.
Influence of Cavity Wall Insulation
Testing pitched-roof constructions with intermediate rafter insulation show that sound insulation rises with the rafter interspace filling degree. Best result is attained at complete filling of the interspace (rafter height). Such constructions are also suitable for buildings that are in the protective areas according to the Aircraft Noise Act. Attaining an equally high weighted apparent sound reduction index with a solid single-leaf wall it would need to have a mass surface density of 250 kg/m2 minimum. This comparison elucidates how acoustically effective two-shell structures are when appropriately dimensioned and Isover mineral wool absorbents are used.
High-pitched roofs with intermediate rafter insulation
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Description of structural design
- Concrete roofing tiles - Concrete roofing tiles
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Sound
50 dB 50 dB 51 dB 52 dB |
High-pitched roof with top rafter insulation
Top-rafter Insulation
Isover top-rafter insulation systems meet the highest demands on high-pitched roof sound insulation. On top-rafter insulation systems both shells - formed by roof cladding and room-facing formwork - are separated by a continuous insulating layer. Acoustic effectiveness requires employment of absorbents featuring low dynamic stiffness at good compression strength.
Isover Top-rafter Insulating System Integra AP
The Isover Integra AP top-rafter insulating system prevents transmission of structure-borne sound between exterior leaf and interior leaf owing to a flat insulating mineral wool layer. Sound transmission over flanking roof construction in row houses and semidetached houses and residential buildings with several loft apartments is important for sound insulation between the living units. There will be no impairment of sound insulation between rooms provided the junction between damped high-pitched roof and apartment or house partition had been engineered appropriately. High-pitched roof constructions for low-energy houses often consist of a combination of intermediate rafter and top-rafter insulation. Besides a low k value of less than 0.20 W/(m2K) they also feature significantly enhanced sound insulation.
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- Concrete roofing tiles
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Sound
43 dB 44 dB 57 dB |