Difference between revisions of "Insulation"
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'''Insulation''' reduces heat transfer, thus | '''Insulation''' reduces heat transfer, thus | ||
| − | * Reduces heat loss in winter, saving on heating costs and improving comfort | + | * Reduces heat loss in winter, saving on [[heating]] costs and improving comfort |
* Reduces rate of heat gain in summer, saving on ac costs. | * Reduces rate of heat gain in summer, saving on ac costs. | ||
| − | * Prevents freezing of pipes | + | * Prevents freezing of [[Plumbing|pipes]] |
| − | * Reduces run cost of | + | * Reduces run cost of [[Domestic Hot Water|hot water]] systems |
| Line 10: | Line 10: | ||
* Solid wall insulation (fitted to wall surfaces) | * Solid wall insulation (fitted to wall surfaces) | ||
* Loft insulation | * Loft insulation | ||
| − | * Pipe insulation to prevent freezing or heat loss | + | * [[Plumbing|Pipe]] insulation to prevent freezing or heat loss |
| − | * HW | + | * [[Domestic Hot Water|HW cylinder]] insulation |
* Underfloor insulation | * Underfloor insulation | ||
| Line 17: | Line 17: | ||
==Types of Insulation== | ==Types of Insulation== | ||
===Trapped Air=== | ===Trapped Air=== | ||
| − | Still air is a good insulator, and is the basis of more or less all insulation products currently used in housing. One way or another, each insulation product traps air, and | + | Still air is a good insulator, and is the basis of more or less all insulation products currently used in housing. One way or another, each insulation product traps air, and its the air that does the job. So if 6" of insulation is compressed to 4", it has the insulation value of 4" of material. |
| − | |||
===Cavities=== | ===Cavities=== | ||
| − | Cavity walls insulate much better than solid walls, and are an early example of domestic trapped air insulation. Walls with no cavity can have a trapped air cavity attached using battens and plasterboard. | + | Cavity walls insulate much better than solid walls, and are an early example of domestic trapped air insulation. Walls with no cavity can have a trapped air cavity attached using [[Timber basics|battens]] and [[Partition Wall|plasterboard]]. |
Large cavities allow some air movement, hence foamy and woolly insulation products give better insulation than a cavity alone. | Large cavities allow some air movement, hence foamy and woolly insulation products give better insulation than a cavity alone. | ||
| − | Battens and other barriers to air movement can be used to improve an empty cavity's insulation a little, but denser insulation products provide better insulation value, and are worth using. | + | Battens and other barriers to air movement can be used to improve an empty cavity's insulation a little, but denser insulation products are now available that provide better insulation value, and are worth using. |
| Line 32: | Line 31: | ||
[[image:Polystyrene beads 1746-4.jpg|thumb|now we know what polystyrene is shipped in]] | [[image:Polystyrene beads 1746-4.jpg|thumb|now we know what polystyrene is shipped in]] | ||
| − | Low cost insulation available in slab form | + | Low cost insulation available in |
| + | * slab form | ||
| + | * as small beads for loose fill & beanbags | ||
| + | * larger chunks for packaging | ||
Mainly used for: | Mainly used for: | ||
| Line 38: | Line 40: | ||
* Wall insulation | * Wall insulation | ||
* Floor insulation | * Floor insulation | ||
| + | * Rarely used for extra fridge & freezer insulation | ||
| − | + | Polystyrene is flammable, and produces toxic smoke on burning. This problem is worse when painted with [[oil]] based [[paint]]s. | |
| − | Polystyrene is | + | Sometimes used for cavity wall insulation |
| + | * Can saturate with [[water]] and cause [[:Category:Damp|damp problems]] | ||
| + | * Beads pour out of any [[Drill bit|hole]] made in the wall if not [[glue]]d | ||
| + | |||
| + | Polystyrene in wall cavities is relatively well protected from fire, and is not considered a fire safety issue. However polystyrene cavity insulation in contact with PVC electrical [[cable]] fitted in cavities causes the cable to leach plasticiser and become unsafe. | ||
| − | + | ====Historic uses==== | |
| − | * | + | Insulating decorative ceiling tiles |
| − | * | + | * Dangerous in a fire |
| + | * Spreads fire rapidly | ||
| + | * Generates thick toxic smoke when burnt | ||
| + | * Ugly | ||
| − | + | A thin crack covering layer on walls | |
| − | + | * Dents very readily | |
| − | + | * Grim news in a fire | |
| − | |||
| − | |||
| − | |||
| − | |||
| − | * | ||
Polystyrene ceiling tiles are best removed for safety, as is polystyrene backed wallpaper. | Polystyrene ceiling tiles are best removed for safety, as is polystyrene backed wallpaper. | ||
| − | |||
===Fibreglass=== | ===Fibreglass=== | ||
| Line 72: | Line 76: | ||
* Produces prodigious loose glass fibres | * Produces prodigious loose glass fibres | ||
* Tiny spiky glass fibres cause splinters | * Tiny spiky glass fibres cause splinters | ||
| − | * Concerns about its safety are occasionally expressed on the basis that it releases miniature sharp spikey non-dissolving airborne fibres, somewhat like | + | * Concerns about its safety are occasionally expressed on the basis that it releases miniature sharp spikey non-dissolving airborne fibres, somewhat like known carcinogenic forms of asbestos. |
* Dust mask should be used during handling | * Dust mask should be used during handling | ||
* Gloves are also recommended to reduce splinters | * Gloves are also recommended to reduce splinters | ||
* Compressing 6" down to 4" gives you the insulation value of 4" of fibreglass. | * Compressing 6" down to 4" gives you the insulation value of 4" of fibreglass. | ||
| − | + | * Much used for loft insulation | |
| − | Much used for loft insulation | ||
| Line 83: | Line 86: | ||
A mineral fibre similar to glass fibre, but denser, so much less airborne fibre. | A mineral fibre similar to glass fibre, but denser, so much less airborne fibre. | ||
* Popularly used for loft insulation | * Popularly used for loft insulation | ||
| − | * Comes in roll form and also loose fill. | + | * Comes in [[Roll Materials|roll form]] and also loose fill. |
| Line 90: | Line 93: | ||
* R value for 1" insulation: 5.3 | * R value for 1" insulation: 5.3 | ||
* Kingspan is the leading manufacturer | * Kingspan is the leading manufacturer | ||
| + | |||
| + | |||
| + | ===Cellulose=== | ||
| + | * Loose fill | ||
| + | * Used in cavities | ||
| + | * Plant fibre | ||
| + | * Made from ground newspaper | ||
| + | * Low cost | ||
| + | * Better performance than fibreglass | ||
| + | * [http://en.wikipedia.org/wiki/Cellulose_insulation wikipedia] | ||
===PVC Cladding=== | ===PVC Cladding=== | ||
| + | * Mainly used on gable wall ends | ||
| + | * Keeps rain off the wall | ||
| + | * Can make a messy wall look ok too, but not the world's favourite finish | ||
| + | |||
| + | |||
| + | ===Timber cladding=== | ||
| + | * Timber cladding is used as an interior and exterior finish | ||
| + | * Provides a degree of insulation | ||
| + | * Several timber designs available | ||
===Insulating render mixes=== | ===Insulating render mixes=== | ||
| − | + | [[Cement]] mixes containing polystyrene beads, leca or vermiculite | |
* Fireproof | * Fireproof | ||
| + | * [[Paint]] to prevent [[water]] ingress and freeze/thaw damage | ||
===Shredded Paper=== | ===Shredded Paper=== | ||
| − | Sometimes used as loose fill loft insulation | + | * Sometimes used as loose fill loft insulation |
| − | + | * Waste paper is treated with fire retardant and chopped or shredded. | |
| − | Waste paper is treated with fire retardant and chopped | + | * Recycled |
| + | * Not [[:Category:Damp|damp]] tolerant | ||
===Cardboard=== | ===Cardboard=== | ||
| − | + | * Very low cost insulation material | |
| − | + | * Its low cost helps ensure higher returns on investment by eliminating much of the investment cost. | |
| − | Cardboard wall insulation is popular in the US, but seems to have had little takeup here in the UK. | + | * Fitting used cardboard results in zero extra manufacturing energy use. |
| − | + | * Cardboard wall insulation is popular in the US, but seems to have had little takeup here in the UK. | |
| − | Its flammability can be resolved by painting it with a mixture of borax & boric acid. | + | * Its flammability can be resolved by painting it with a mixture of borax & boric acid. |
| − | + | * Its damp susceptible, and can support [[Mould basics|mould]] if damp | |
| − | + | * Should not be used in situations where damp may occur. | |
| − | |||
| − | |||
* Available free | * Available free | ||
| − | |||
| − | |||
| − | === | + | ===Papercrete=== |
| − | A relatively novel building product, low density [[Papercrete|papercrete]] has good insulation properties and is made mostly out of waste paper and cement, with a number of possible additions including expanded polystyrene and fire retardants. | + | A relatively novel building product, low density [[Papercrete|papercrete]] has good insulation properties and is made mostly out of waste paper and [[cement]], with a number of possible additions including expanded polystyrene and fire retardants. |
It is not on general sale and requires either a specialist mixer to produce or ready chopped paper. | It is not on general sale and requires either a specialist mixer to produce or ready chopped paper. | ||
| Line 128: | Line 148: | ||
===Sheep's Wool=== | ===Sheep's Wool=== | ||
| − | Sheep's wool is sometimes used | + | Sheep's wool is sometimes used instead of fibreglass or rockwool. |
| − | * Natural | + | * Natural |
* Non-irritant, no protective clothes required. | * Non-irritant, no protective clothes required. | ||
* Can absorb and release moisture. Unlike glass/mineral wool where moisture reduces insulation. | * Can absorb and release moisture. Unlike glass/mineral wool where moisture reduces insulation. | ||
| − | * Is a carbon | + | * Is a carbon sink, over 45% of the weight is carbon |
* Life 50+ years | * Life 50+ years | ||
| − | * | + | * Biodegradable |
* Does not spread fire, but chars. | * Does not spread fire, but chars. | ||
| − | * Treated against insects | + | * Treated against [[:Category:Pests|insects]] |
* Costs more than fibreglass & rockwool | * Costs more than fibreglass & rockwool | ||
* Cheap if you or a nearby sheep farmer has wool they can't sell, unwashed wool is not allowed to be used. | * Cheap if you or a nearby sheep farmer has wool they can't sell, unwashed wool is not allowed to be used. | ||
| + | |||
===Straw=== | ===Straw=== | ||
Straw has long been used as insulation, and is another low cost option. | Straw has long been used as insulation, and is another low cost option. | ||
| − | * Susceptible to damp & mould | + | * Susceptible to damp & [[mould]], but less so than cardboard |
* Nest material for birds | * Nest material for birds | ||
| − | * | + | * Can contain unhatched [[:Category:Pests|insect eggs]] |
| − | * Flammable, which can be resolved by plastering over the straw to deny the admittance of air for combustion. | + | * Flammable, which can be resolved by [[Plastering Beginner's Guide|plastering]] over the straw to deny the admittance of air for combustion. |
* Low cost | * Low cost | ||
* Used to be available in slab form, which is occasionally seen in use. | * Used to be available in slab form, which is occasionally seen in use. | ||
| Line 152: | Line 173: | ||
===Clay beads=== | ===Clay beads=== | ||
LECA expanded clay beads are occasionally used as house insulation. | LECA expanded clay beads are occasionally used as house insulation. | ||
| − | * Non- | + | * Non-flammable |
| + | * Unaffected by damp | ||
| + | * Used as loose fill, mainly under floors | ||
| + | |||
| − | Vermiculite | + | ===Vermiculite=== |
| + | Similar to expanded clay beads | ||
| Line 161: | Line 186: | ||
* Degraded by UV light. | * Degraded by UV light. | ||
* Flammable | * Flammable | ||
| − | * | + | * Used as greenhouse secondary glazing |
* May last ok in dark places eg lofts & cupboards. | * May last ok in dark places eg lofts & cupboards. | ||
===Felt=== | ===Felt=== | ||
| − | Felt strip is used as pipe lagging | + | Felt strip is used as pipe lagging |
| + | * Its wound around the pipe(s) and secured with [[tape]] | ||
* Brown, hairy and untidy looking | * Brown, hairy and untidy looking | ||
| − | * Best used for pipes out of sight | + | * Best used for [[Plumbing|pipes]] out of sight |
| − | * | + | * Good for insulating grouped pipes, where foam jackets don't fit. |
| − | + | * Foam tube is much quicker for insulating single pipes | |
===Foamed Concrete=== | ===Foamed Concrete=== | ||
| + | * Lightweight concrete blocks have insulation value | ||
| + | * Insulation is one of the reasons for their use in interior walls | ||
| + | * They don't survive outdoors unless rendered. | ||
| + | |||
===Aerogel=== | ===Aerogel=== | ||
| − | Aerogel is a very low density glass/air gel rated at 0.013 W/mK | + | * Aerogel is a very low density glass/air gel rated at 0.013 W/mK |
| + | * High temperature resistance | ||
| + | * Its high price restricts it to applications where high insulation value per size is necessary | ||
| + | * Sold by [http://www.spacetherm.com/products.htm Spacetherm]. | ||
| − | |||
| − | |||
| + | ==Unsatisfactory Insulation Materials== | ||
| + | [[Carpet]] | ||
| + | * Too thin to give much insulation | ||
| + | * Flammable | ||
| + | * Reduces draughts | ||
| − | + | Polystyrene ceiling tiles & wallpaper | |
| − | + | * Too thin to give much benefit | |
| − | + | * Very flammable | |
| − | + | * Dents very easily | |
| − | |||
| − | |||
| − | + | Sand | |
| − | * | + | * Traps air but is too thermally conductive |
| − | |||
| − | |||
| − | |||
| − | + | Bubblewrap | |
| − | + | * Degrades quickly from UV exposure | |
| − | |||
| − | * | ||
| − | * | + | [[Spray-on Roof Insulation]] |
| − | * | + | * Traps water, prone to causing [[Wood Rot|rot]] |
| + | * Makes the roofcovering non-reusable | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
==By Application== | ==By Application== | ||
| Line 214: | Line 238: | ||
* Rockwool | * Rockwool | ||
* Fibreglass | * Fibreglass | ||
| − | * | + | * Shredded or chopped fire retardant treated paper |
* Sheep's wool (available in batts as Thermafleece or rolls from www.BlackMountainInsulation.com) | * Sheep's wool (available in batts as Thermafleece or rolls from www.BlackMountainInsulation.com) | ||
| + | |||
===Roof=== | ===Roof=== | ||
| − | * Polystyrene | + | * Polystyrene - cheap |
| − | * Straw | + | * Straw - very cheap |
| − | * Polyisocyanurate where depth of insulation needs to be minimised | + | * Polyisocyanurate - where depth of insulation needs to be minimised |
===Cavity Wall Insulation=== | ===Cavity Wall Insulation=== | ||
Fitted to existing wall cavities | Fitted to existing wall cavities | ||
| − | * Rockwool | + | * Rockwool |
| − | * Fibreglass | + | * Fibreglass |
| − | * Polystyrene bead | + | * Polystyrene bead |
| Line 236: | Line 261: | ||
* Rockwool batts | * Rockwool batts | ||
* Cardboard | * Cardboard | ||
| + | * Polyisocyanurate | ||
| Line 241: | Line 267: | ||
Fitted to the surface of solid walls, and rarely to cavity walls to increase insulation level further. | Fitted to the surface of solid walls, and rarely to cavity walls to increase insulation level further. | ||
* Proprietary hard surfaced insulating sheets are mostly used. | * Proprietary hard surfaced insulating sheets are mostly used. | ||
| + | * Polyisocyanurate | ||
* Polystyrene foam backed plasterboard sheets may also be used | * Polystyrene foam backed plasterboard sheets may also be used | ||
| − | == | + | ==Free insulation options== |
* Waste cardboard sheet | * Waste cardboard sheet | ||
* Shredded waste polystyrene | * Shredded waste polystyrene | ||
| − | |||
* Straw | * Straw | ||
| + | * Bubblewrap for water tanks | ||
| + | * Scrap clothing as pipe insulation | ||
| Line 255: | Line 283: | ||
* Fireproof materials such as fibreglass and mineral wool act as a fire barrier if they remain in position. | * Fireproof materials such as fibreglass and mineral wool act as a fire barrier if they remain in position. | ||
| − | * Fire | + | * Fire retardant materials will burn away when flames reach them, but will not spread the fire further. Thus these do not act as fire barriers. |
* Flammable materials such as untreated cardboard can ignite and spread fire. These products should generally be treated before use with a fire retardant, although there are examples where pattern of use provides another means to prevent spread of fire (eg plastered strawbale construction). | * Flammable materials such as untreated cardboard can ignite and spread fire. These products should generally be treated before use with a fire retardant, although there are examples where pattern of use provides another means to prevent spread of fire (eg plastered strawbale construction). | ||
| + | |||
| + | |||
| + | ==Insulation Values== | ||
| + | To be worked into the article | ||
| + | * 20mm marmox R= 0.60 | ||
| + | * uninsulated cavity wall R=0.73, U=1.37 | ||
| + | * 50mm celotex U=0.40 R=2.63 | ||
| + | * Single brick - R = 0.12 | ||
| + | * Unventilated Cavity - R = 0.18 | ||
| + | * 18mm Plywood - R = 0.70 | ||
==See Also== | ==See Also== | ||
| + | * [[Heat loss]] | ||
* [http://www.livinginpaper.com/tests.htm Borax Fire Retardant] | * [http://www.livinginpaper.com/tests.htm Borax Fire Retardant] | ||
* [http://www.lafargeplasterboard.co.uk/products/concepts/thermal1.htm Thermalcheck insulated plasterboard] | * [http://www.lafargeplasterboard.co.uk/products/concepts/thermal1.htm Thermalcheck insulated plasterboard] | ||
Revision as of 18:24, 18 December 2009
Insulation reduces heat transfer, thus
- Reduces heat loss in winter, saving on heating costs and improving comfort
- Reduces rate of heat gain in summer, saving on ac costs.
- Prevents freezing of pipes
- Reduces run cost of hot water systems
Main DIY Applications
- Wall cavity insulation (for either original wall cavities or a retrofitted cavity behind plasterboard)
- Solid wall insulation (fitted to wall surfaces)
- Loft insulation
- Pipe insulation to prevent freezing or heat loss
- HW cylinder insulation
- Underfloor insulation
Types of Insulation
Trapped Air
Still air is a good insulator, and is the basis of more or less all insulation products currently used in housing. One way or another, each insulation product traps air, and its the air that does the job. So if 6" of insulation is compressed to 4", it has the insulation value of 4" of material.
Cavities
Cavity walls insulate much better than solid walls, and are an early example of domestic trapped air insulation. Walls with no cavity can have a trapped air cavity attached using battens and plasterboard.
Large cavities allow some air movement, hence foamy and woolly insulation products give better insulation than a cavity alone.
Battens and other barriers to air movement can be used to improve an empty cavity's insulation a little, but denser insulation products are now available that provide better insulation value, and are worth using.
Expanded Polystyrene
Low cost insulation available in
- slab form
- as small beads for loose fill & beanbags
- larger chunks for packaging
Mainly used for:
- Roof insulation
- Wall insulation
- Floor insulation
- Rarely used for extra fridge & freezer insulation
Polystyrene is flammable, and produces toxic smoke on burning. This problem is worse when painted with oil based paints.
Sometimes used for cavity wall insulation
- Can saturate with water and cause damp problems
- Beads pour out of any hole made in the wall if not glued
Polystyrene in wall cavities is relatively well protected from fire, and is not considered a fire safety issue. However polystyrene cavity insulation in contact with PVC electrical cable fitted in cavities causes the cable to leach plasticiser and become unsafe.
Historic uses
Insulating decorative ceiling tiles
- Dangerous in a fire
- Spreads fire rapidly
- Generates thick toxic smoke when burnt
- Ugly
A thin crack covering layer on walls
- Dents very readily
- Grim news in a fire
Polystyrene ceiling tiles are best removed for safety, as is polystyrene backed wallpaper.
Fibreglass
Comes in roll form and also loose fill.
- Lasts the life of the building no matter what life throws at it.
- Waterproof
- Insectproof
- Verminproof
- Fireproof
- Springs back to shape if squashed
- Lightweight
- Loosefill can be blown about in a draughty loft
- Produces prodigious loose glass fibres
- Tiny spiky glass fibres cause splinters
- Concerns about its safety are occasionally expressed on the basis that it releases miniature sharp spikey non-dissolving airborne fibres, somewhat like known carcinogenic forms of asbestos.
- Dust mask should be used during handling
- Gloves are also recommended to reduce splinters
- Compressing 6" down to 4" gives you the insulation value of 4" of fibreglass.
- Much used for loft insulation
Rockwool
A mineral fibre similar to glass fibre, but denser, so much less airborne fibre.
- Popularly used for loft insulation
- Comes in roll form and also loose fill.
Polyisocyanurate
- Survives temperatures upto 400C
- R value for 1" insulation: 5.3
- Kingspan is the leading manufacturer
Cellulose
- Loose fill
- Used in cavities
- Plant fibre
- Made from ground newspaper
- Low cost
- Better performance than fibreglass
- wikipedia
PVC Cladding
- Mainly used on gable wall ends
- Keeps rain off the wall
- Can make a messy wall look ok too, but not the world's favourite finish
Timber cladding
- Timber cladding is used as an interior and exterior finish
- Provides a degree of insulation
- Several timber designs available
Insulating render mixes
Cement mixes containing polystyrene beads, leca or vermiculite
Shredded Paper
- Sometimes used as loose fill loft insulation
- Waste paper is treated with fire retardant and chopped or shredded.
- Recycled
- Not damp tolerant
Cardboard
- Very low cost insulation material
- Its low cost helps ensure higher returns on investment by eliminating much of the investment cost.
- Fitting used cardboard results in zero extra manufacturing energy use.
- Cardboard wall insulation is popular in the US, but seems to have had little takeup here in the UK.
- Its flammability can be resolved by painting it with a mixture of borax & boric acid.
- Its damp susceptible, and can support mould if damp
- Should not be used in situations where damp may occur.
- Available free
Papercrete
A relatively novel building product, low density papercrete has good insulation properties and is made mostly out of waste paper and cement, with a number of possible additions including expanded polystyrene and fire retardants.
It is not on general sale and requires either a specialist mixer to produce or ready chopped paper.
Sheep's Wool
Sheep's wool is sometimes used instead of fibreglass or rockwool.
- Natural
- Non-irritant, no protective clothes required.
- Can absorb and release moisture. Unlike glass/mineral wool where moisture reduces insulation.
- Is a carbon sink, over 45% of the weight is carbon
- Life 50+ years
- Biodegradable
- Does not spread fire, but chars.
- Treated against insects
- Costs more than fibreglass & rockwool
- Cheap if you or a nearby sheep farmer has wool they can't sell, unwashed wool is not allowed to be used.
Straw
Straw has long been used as insulation, and is another low cost option.
- Susceptible to damp & mould, but less so than cardboard
- Nest material for birds
- Can contain unhatched insect eggs
- Flammable, which can be resolved by plastering over the straw to deny the admittance of air for combustion.
- Low cost
- Used to be available in slab form, which is occasionally seen in use.
Clay beads
LECA expanded clay beads are occasionally used as house insulation.
- Non-flammable
- Unaffected by damp
- Used as loose fill, mainly under floors
Vermiculite
Similar to expanded clay beads
Bubble wrap
Only rarely used in houses, wrapped round water tanks or used as an insulating window blind.
- Degraded by UV light.
- Flammable
- Used as greenhouse secondary glazing
- May last ok in dark places eg lofts & cupboards.
Felt
Felt strip is used as pipe lagging
- Its wound around the pipe(s) and secured with tape
- Brown, hairy and untidy looking
- Best used for pipes out of sight
- Good for insulating grouped pipes, where foam jackets don't fit.
- Foam tube is much quicker for insulating single pipes
Foamed Concrete
- Lightweight concrete blocks have insulation value
- Insulation is one of the reasons for their use in interior walls
- They don't survive outdoors unless rendered.
Aerogel
- Aerogel is a very low density glass/air gel rated at 0.013 W/mK
- High temperature resistance
- Its high price restricts it to applications where high insulation value per size is necessary
- Sold by Spacetherm.
Unsatisfactory Insulation Materials
- Too thin to give much insulation
- Flammable
- Reduces draughts
Polystyrene ceiling tiles & wallpaper
- Too thin to give much benefit
- Very flammable
- Dents very easily
Sand
- Traps air but is too thermally conductive
Bubblewrap
- Degrades quickly from UV exposure
- Traps water, prone to causing rot
- Makes the roofcovering non-reusable
By Application
Loft
- Rockwool
- Fibreglass
- Shredded or chopped fire retardant treated paper
- Sheep's wool (available in batts as Thermafleece or rolls from www.BlackMountainInsulation.com)
Roof
- Polystyrene - cheap
- Straw - very cheap
- Polyisocyanurate - where depth of insulation needs to be minimised
Cavity Wall Insulation
Fitted to existing wall cavities
- Rockwool
- Fibreglass
- Polystyrene bead
Wall Cavity Insulation
Fitted to retrofitted cavities
- Polystyrene slab
- Fibreglass
- Rockwool batts
- Cardboard
- Polyisocyanurate
Solid Insulation for Walls
Fitted to the surface of solid walls, and rarely to cavity walls to increase insulation level further.
- Proprietary hard surfaced insulating sheets are mostly used.
- Polyisocyanurate
- Polystyrene foam backed plasterboard sheets may also be used
Free insulation options
- Waste cardboard sheet
- Shredded waste polystyrene
- Straw
- Bubblewrap for water tanks
- Scrap clothing as pipe insulation
Fire
With 69,000 house fires in 2001, the performance of insulation in a fire affects loss of property and life. There are 3 main categories of fire performance:
- Fireproof materials such as fibreglass and mineral wool act as a fire barrier if they remain in position.
- Fire retardant materials will burn away when flames reach them, but will not spread the fire further. Thus these do not act as fire barriers.
- Flammable materials such as untreated cardboard can ignite and spread fire. These products should generally be treated before use with a fire retardant, although there are examples where pattern of use provides another means to prevent spread of fire (eg plastered strawbale construction).
Insulation Values
To be worked into the article
- 20mm marmox R= 0.60
- uninsulated cavity wall R=0.73, U=1.37
- 50mm celotex U=0.40 R=2.63
- Single brick - R = 0.12
- Unventilated Cavity - R = 0.18
- 18mm Plywood - R = 0.70