Insulation helps to protect the building from external temperature and sound. By installing insulation in buildings, the heating and cooling loads reduce in a significant way thereby reducing energy loads and cost. Insulation refers to reduction in the rate of heat transfer to buildings. It also helps in achieving human comfort condition.
Transmission of sound can be of two ways – impact and airborne sound.
- Impact sound – It is caused by the direct impact of building fabric, transmitting the sound through the structure.
- Airborne sound – Sound transmits from the equipment and human sound. Air sound relates to the mass of the wall.
The reduction in sound energy passing through a building element is expressed in decibels(dB).
How to Identify good Insulators
- The absorption of sound relates to the porosity of the materials. Light materials with open pores or fibrous are good in sound absorbing compared to hard and smooth surfaces that are highly reflective to sound.
- Materials having low thermal conductivity are good insulators.
Applications and forms of Insulation Materials
- Structural insulation
- rigid and semi-rigid sheets and slabs
- loose fill, blanket materials and applied finishes
- Aluminum foil
Types of Insulation Materials
Types of Insulation According to the composition
- Inorganic Insulation materials
- Organic Insulation materials
Inorganic Insulation Materials
Foamed Concrete
- It is a fire and frost resistant material.
- Can be easily placed without compaction.
- Suitable for insulation for floors and flat roofs.
Gypsum Plaster
- Gypsum Plasterboards are light-weight walls.
- Using two layer of Gypsum Plasterboards (different thickness) reduces sound transmission as these resonate at different frequencies.
Wood Wool Slabs
- Wood wool slabs are manufactured from composition of wood fibers and cement. Since it consists of cement, it is fire and rot resistance.
- It has good sound absorption and insulating properties, due to the open textured surface, along with load bearing properties.
- Mostly used as roof decking material.
Mineral Wool
- Mineral wool is manufactured from volcanic rock (silica, alumina, and magnesium oxide) blended with coke and limestone and fused at 1500c in a furnace. They are turned into fibers and coated with resin binder and water-repellant mineral oil. Then it is compressed and cured ,cut into final products of rolls or slabs.
- It is non-combustible, water-repellant, rotproof, contains no CFCs or HCFCs.
- It is available in various forms – loose, mats, batts, semi-rigid slabs, rigid slabs, resin-bonded slabs, weather resistant boards, pre-painted boards, ceiling tiles.
- Used for cavity fills, lofts, floor and roof insulation, exterior cladding, ceiling tiles, etc.
- Effective in reducing transmission of sound.
Glass Wool
- Glass wood is made by crown process similar to the manufacture of Glass wool.
- It is non-combustible, water-repellant, rotproof, contains no CFCs or HCFCs.
- It is available in various forms – loose, rolls, batts (rigid and semi-rigid),slabs, boards, panels, etc.
- Used as fills in cavities, roofs, floors, internal walls, ceiling tiles.
Cellular of Foamed Glass Blocks
- They are manufactured from a mixture of crushed glass and fine carbon powder, which on heating to 1000â—¦C, causes the carbon to oxidize, creating bubbles within the molten glass. The glass is cooled and cut to size.
- It is durable and easy to work, has high compressive strength.
- Non-combustible, water resistant for its closed cell structure, contains no CFCs.
- Appropriate for roof insulation, including green roofs and roof top car parks. Also for floor insulation and cavity fills for walls.
Exfoliated Vermiculite
- It is manufactured by heating the natural micaceous mineral. The material contains 90% air by volume.
- Used as a loose fill for loft insulation.
- Also used as fire stop seals.
Expanded Perlite
- Expanded Perlite is manufactured by heating natural volcanic rock minerals.
- It is used for loose and bonded in situ insulation for roofs, ceilings, walls and floors also as preformed boards.
Calcium Silicate
- It is durable and has good impact resistance.
- Wall boards are manufactured with calcium silicate boards.
Aerogels
- They are hydrophobic amorphous silica materials.
- Extremely light-weight and are highly porous
Organic Insulation Materials
Cellulose
- It is manufactured from shredded recycle paper, paper pulp and other organic wastes.
- It is treated with borax for fire resistance.
- This recycled cellulose has a low embodied energy and cost-effective.
- Used for internal floors, lofts, where the required eaves ventilation gap is maintained. Also for other cavities, including sloping roof voids.
- Cellulose is an effective absorber of airborne sound.
Cork
- Cork is an environmentally friendly material.
- The Cork granules are bonded with natural resin under heat and pressure to form blocks or boards. These boards are used as roof insulation.
- To increase thermal insulation, it may be bonded to ployutherene foam.
Sheep’s Wool
- It is a renewable resource efficient insulation material with low embodied energy.
- Wool is a hygroscopic material.
- It is available in grey wool batts, which contain 85% wool and 15%polyster,ranging in thickness from 50 and 75 to 100 mm thick.
- They are treated with insecticide to prevent beetle attack.
- Suitable for ventilated loft applications between joists or rafters and for timber frame construction.
Recycled Plastic
- Manufactured from recycled plastic bottles into a non-woven, clean material.
- Used for loft insulation.
- Available as rolls of thickness from 100-200mm.
Flax, Hemp and Coconut Fiber
- Sustainable insulation materials.
- Suitable for ventilated or breathing constructions, ceilings, walls, lofts, floors, roofs, etc.
- They are treated with borax for fire and insect resistance.
- They have good thermal and acoustic insulation properties.
Fibre Insulation Board
- Used for wall linings and backed with aluminum foil for enhancing thermal insulation.
- Soft insulation boards have good sound absorption properties.
- Bitumen-impregnated insulating board, with its enhanced water-resistant properties, is used as a thermal insulation layer on concrete floors.
Expanded Polystyrene
- Expanded Polystyrene (EPS) is a combustible material.
- It is a closed-cell product, therefore resistance to water and acids.
- It is free from CFCs and HCFCs.
- Available as
- Polystyrene beads – fill for cavity insulation.
- Expanded Polystyrene boards
Extruded Polystyrene
- Extruded Polystyrene (XPS) is manufactured by a vacuum process.
- It has a closed-cell structure with very low water-absorption and vapor – transmission properties.
- Used for cavity fill, pitched roof ,floor insulation.
Foam Insulation
Types of Foam Insulation
- Polyurethane Foam
- Polyisocyanurate Foam
- Urea-Formaldehyde Foam
- Phenolic Foam
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