Polystyrene is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed. Expanded polystyrene (EPS) is a rigid and tough, closed-cell foam. It is usually white and made of pre-expanded polystyrene beads. Polystyrene is one of the most widely used plastics, the scale of its production being several billion kilograms per year.
Polystyrene foams are produced using blowing agents that form bubbles and expand the foam. In expanded polystyrene, these are usually hydrocarbons such as pentane
Extruded polystyrene (XPS)
Extruded polystyrene foam (XPS) consists of closed cells, offers improved surface roughness and higher stiffness and reduced thermal conductivity. It is slightly denser and therefore slightly stronger than EPS.
Water vapour diffusion resistance (μ) of XPS is very low - making it suitable for application in wetter environments.
Phenolic foam insulation is made from a resole resin in the presence of an acid catalyst, blowing agents (such as pentane) and surfactants.
Polyisocyanurate/ Polyurethane foam (PIR/PUR)
Polyurethane (PUR and PU) is a polymer composed of organic units joined by carbamate (urethane) links. Polyurethane can be made in a variety of densities and hardnesses by varying the isocyanate, polyol or additives.
Polyisocyanurate, also referred to as PIR, is a thermoset plastic typically produced as a foam and used as rigid thermal insulation. Its chemistry is similar to polyurethane (PUR) except that the proportion of methylene diphenyl diisocyanate (MDI) is higher and a polyester-derived polyol is used in the reaction instead of a polyether polyol. Catalysts and additives used in PIR formulations also differ from those used in PUR.
Glass mineral wool
Made from molten glass, usually with 20% to 30% recycled industrial waste and post-consumer content. The material is formed from fibres of glass arranged using a binder into a texture similar to wool. The process traps many small pockets of air between the glass, and these small air pockets result in high thermal insulation properties. The density of the material can be varied through pressure and binder content.
Rock mineral wool
Rock (Stone) mineral wool is a furnace product of molten rock at a temperature of about 1600 °C, through which a stream of air or steam is blown. More advanced production techniques are based on spinning molten rock in high-speed spinning heads somewhat like the process used to produce candy floss. The final product is a mass of fine, intertwined fibres with a typical diameter of 2 to 6 micrometers. Mineral wool may contain a binder, often a Ter-polymer, and an oil to reduce dusting
Largely manufactured from recycled glass (e.g. windscreens) and mineral base materials such as sand and without the use of binding agents. The ingredients are melted into molten glass, which is cooled and crushed into a fine powder. The powdered glass is poured into molds and heated (below the melting point) in a "sintering" process that causes the particles to adhere to one another. Next, a small amount of finely ground carbon-black is added and the material is heated in a "cellulation" process. Here, the carbon reacts with oxygen, creating carbon dioxide, which creates the insulating bubbles in the (material). CO2 accounts for more than 99% of the gas in the cellular spaces.
Wool insulation is made from sheep wool fibres that are either mechanically held together or bonded using between 5% and 15% recycled polyester adhesive to form insulating batts and rolls. Sheep are no longer farmed primarily for their wool; however, they need to be clipped annually to protect the health of the animal. The wool used to manufacture insulation is the wool discarded as waste by other industries due to its colour or grade
Cellulose insulation is a material made from recycled newspaper. The paper is shredded and inorganic salts, such as boric acid, are added for resistance to fire, mould, insects and vermin. The insulation is installed either blown or damp-sprayed depending on application.
The success of wood fibre insulation derives from an attractive environmental profile combined with a whole bag of functions including rigid insulation, sheathing and sarking for timber frames, roofs and flooring as well as flexible insulation for studs and rafters.
Wood of course is renewable, it sequesters carbon during its growth and product production is relatively free from pollution. The insulation value of wood fibre boards is not as dimensionally efficient as some of the orthodox petro-chemical materials - but it's no slouch either - typically coming in with a 'k value' range of between 0.038-0.043 W/mK depending on format.
Hemp fibres are produced from hemp straw of the hemp plant. Most hemp is imported, but an increasing amount of home-grown crop is becoming available. Hemp grows up to a height of nearly 4 metres within a period of 100-120 days. Because the plants shade the soil, no chemical protection or toxic additives are required for hemp cultivation. The product is composed of, usually, 85% hemp fibre with the ballance made up of polyester binding and 3-5% soda added for fire proofing.
Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such asbarley, oats, rice, rye and wheat.
Internal wall insulation is an economic and alternative way to insulate solid masonry wall with inner insulation designed to increase the thermal performance and improve its airtightness. Most often it requires the use of PIR rigid boards, phenolic boards or rock wool roll. The thickness of insulation needed to insulate the wall internally strongly depends on the specific U-value that you want to achieve. A lower figure means better thermal performance. Current Building Regulations require a maximum U-value of 0.3W/m2 for existing buildings (0.16W/m2 for new buildings). Achieving that U-value for solid walls will mean installing at least 120mm of Kingspan, Xtratherm or Celotex rigid insulation. However, Kingspan Kooltherm® K118 is the most commonly used insulating material that meets current U-value requirements with just 50mm (62.5mm) thickness. Since is only 50mm thick it is a top-class three-in-one product for internal wall insulation used as mechanically fixed and adhesively bonded 'dot and dab' insulated plasterboard. The Kingspan Kooltherm K-range comprises the thinnest commonly used insulation products for any specific U-value. With a fibre-free rigid thermoset phenolic core, and a thermal conductivity of 0.018 - 0.023 W/mK, these are the most thermally efficient insulation products commonly used in internal wall applications. There are many other popular UK products such as Knauf EPS Thermal Laminate or Gyproc ThermaLine Basic Insulated Plasterboard. However meeting specified U-value requirements won’t be possible with such materials as it is low cost product based on EPS core designed only for single walls. For instance, if you insulating less than 50% of the room. All other internal insulation products would require bulkier product to be used: 120mm Celotex PIR, 150mm of Knauf® or Rockwool® Mineral Wool and 200mm of EPS100 polystyrene. It is worth to mention insulation called 10mm Sempatap Thermal Wallpaper. This type of insulation became extremely popular in the UK due to their unique ultra-thin thickness properties. Internal insulation will straightforwardly absorb sound waves and reduce vibration due to its density. Because of that, it promotes comfort and privacy, protecting people from ‘outside-to-inside’ noise such as traffic, and ‘inside-to-inside’ noise from neighbouring dwellings. If you insulate more than 50% of the internal walls of the room you need Building Regulation approval. If you live in a house with no cavity walls it is not recommended to use such insulation as it may get you damp problems. If your house was built after the 1920s, it is likely to have cavity walls.
Internal wall insulation is 50% cheaper than external wall insulation but unfortunately less effective, potentially more problematic and more disruptive. It needs careful planning as it more likely causes damp problems.
Also you should expect to lose at least 100mm on each wall when insulating interior walls. The thickness of internal wall insulation varies. You can expect it to be anywhere from 62.5mm to 200mm.
IS INTERNAL WALL INSULATION WORTH IT?
Colloquially speaking if you don't have any other options to insulate your solid wall, an internal wall insulation system is the way to go, the more so as its cost is much lower. The major advantage of internal insulation compared to other insulation methods is nothing but the insulation cost. Regardless of the manufacturer, internal wall insulation will add physical thickness to the wall, most evident at the reveals and eaves, and also will keep the wall at external ambient temperature and thereby draw the dew point towards the internal surface. To help prevent damp penetration, a vapour control layer will need to be installed. It may also disrupt things inside your property in the way that any refurbishment would, so you won't be able to easily live in the house during the work. On the other hand the internal surface of an insulated wall will be warmer. Installing internal wall insulation is better than doing nothing, for sure. You have better payback than external wall insulation, which possibly makes it worthwhile overcoming mentioned problems. Moreover, internal wall insulation grants are available as part of the Government’s Energy Company Obligation (ECO). The scheme provides grants for home owners and private renters who would otherwise be unable to afford to insulate their homes. Grants are paid for by energy companies and the scheme aims to reduce fuel poverty while also reducing carbon emissions.
INTERNAL WALL INSULATION COST
The costs given here are given in good faith as an indicative guide only and should be used with understanding. Insulationgo Limited cannot accept any liability for any budget produced using these figures.
The actual cost of internal wall insulation will vary according to the type of insulation specified. You should expect to pay anything between £10/m2 to £45/m2 and £130/m2 when a new stud wall is built. In terms of m2 coverage cost internal insulation can be classified in particular order:
But when it comes to performance the list takes the following form:
Phenolic Boards Insulation - Thermal Conductivity of 0.018W/mK
PIR Rigid Insulation Boards - Thermal Conductivity of 0.022W/mK
Rock wool Insulation - Thermal Conductivity of 0.035W/mK
Fibreglass Insulation - Thermal Conductivity of 0.044W/mK
Sempatap thermal wallpaper - Thermal Conductivity of 0.194W/mK
TYPES OF INTERNAL WALL INSULATION
Depending on the available space and your budget you can choose between 6 types of internal wall insulation.
1. PHENOLIC INSULATED PLASTERBOARD
Phenolic insulation bonded to plasterboard is a premium performance, factory-bonded wallboard to a fibre-free rigid thermoset phenolic core insulant. It provides a level of performance that is unrivalled in the world of rigid thermoset insulation materials with a thermal conductivity of just 0.018 W/mK across all thicknesses. Manufactured with a blowing agent that has zero ODP and low GWP, it is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining. Provides internal dry lining and insulation in just one fixing operation, giving faster completion times. Boards provide exceptional thermal performance for both new build and refurbishment projects. Can be plastered with either Thistle Board Finish or Thistle MultiFinish plaster. All boards are easily applicable measuring 2400mm x 1200mm. Depending on the design, you can choose from various brands. All of the brands offer a variety of sizes and thicknesses. Kingspan Kooltherm K118 and its alternative Xtratherm Safe-R SR/TB insulated boards are the most effective type of rigid phenolic insulation boards currently available in the UK.
Cost: £35.42/m² (ex VAT) 62.5mm, £25/m² installation Disadvantages: expensive to buy, causes pipework corrosion.
2. THIN THERMAL WALLPAPER
Sempatap Thermal solid wall insulation is a 10mm thick roll of insulation manufactured from latex foam that’s faced with a coated woven fiberglass layer. It’s been used in many applications by local housing authorities, private landlords and homeowners to minimise their energy bill and improve the thermal performance of their home. Sempatap thermal has been tested by numerous organisations including the National Physical Laboratory whose results showed that it will reduce the ‘u’ value (coldness) of a wall by nearly 30%. Sempatap thermal not only has outstanding thermal performance but can also be used as acoustic insulation on walls and ceilings. It is easy and quick to install and the economic solution for insulating your home to reduce heat loss and lower your heating bills. It is applied much like wallpaper. Since it’s only 10mm thick there’s no need to fiddle with extending services. On a standard solid 9 inch brick wall, Sempatap Thermal can make the wall up to 30% more efficient offering thermal resistance of 0.194W/mK
Sempatap Thermal Wallpaper
Cost: £22.80/m2 (ex VAT) 10mm, £16/m² installation Disadvantages: expensive to buy
3. PIR INSULATED PLASTERBOARDS
PIR insulation bonded to plasterboard is a high performance, easy to install polyisocyanurate insulation board, laminated to a piece of 12.5mm or 9.5mm tapered edge plasterboard. These insulated plasterboards also incorporate an integral vapour control layer, which helps to reduce the risk of condensation. Moreover, it provides a continuous layer of thermal insulation across studs in timber frame walls removing the ‘thermal shorts’ that occur at the framing which can reduce the insulation value of a conventional wall by up to 20%. Designed to achieve excellent thermal u-value where minimal cavity is required giving buildings continued thermal efficiency throughout their life span. In terms of thermal conductivity, panels can be classified as a middle class product offering 0.022W/mk. They are easy to handle and quick to install. All boards are easily applicable measuring 2400mm x 1200mm. Boards can be fixed with plasterboard screws or even adhesive, making it an easier option. The thermal laminates boards are suitable for direct bonding ('dot and dab') and mechanically fixed installation techniques. Therefore it has been incredibly popular due to installation time and cost. The ability to install quickly is a huge advantage. This 2 in 1 product brings a whole host of benefits to your home. Starting from low labour costs to low heating bills. Future costs will be kept down due to the energy efficiency of Thermal Plasterboard. In fact, 72.5mm Celotex PIR core insulated plasterboard turned out to be a great alternative to phenolic core 62.5mm Kingspan Kooltherm K118.
Cost: £24.15/m² (ex VAT) 62.5mm, £16/m² installation Disadvantages: expensive to buy
4. EPS INSULATED PLASTERBOARD
EPS insulated plasterboard so called "Thermal laminate" or "Thermal basic" is a combination of a 9.5mm gypsum based wallboard, strongly bonded to expanded polystyrene (EPS) insulant that can be used internally in new build and refurbishment projects requiring a basic thermal upgrade. These types of panels are often associated with the brands such as British Gypsum, Knauf or Warmline. All brands offer thinnest insulated plasterboard as thin as 22mm thick and offer certified thermal conductivity of 0.038W/mK. Those types of insulation are no doubt the best available options in the UK. They are quick and easy to install measuring in length 2400mm and 1200mm in width. Omitting all the details it can be said that they were all designed to be a simple and effective way to improve the thermal efficiency in both walls and roof applications.
Cost: £16.31/m² (ex VAT) 40mm, £16/m² installation Disadvantages: suitable only where the basic level of performance is required
5. FIBREGLASS INTERNAL WALL INSULATION ROLL
Fibreglass insulation is essentially an insulating material that is built into your internal side of your wall. Glass wool is one of the most popular insulation used to insulate walls internally. It is probably the most common and non-combustible type of insulation used to insulate a wall from inside, however it’s itchy and gets everywhere with very little effort. If the insulation gets wet, you will need to replace it a soon as possible. To get decent thermal performance, you need a lot of insulation rolls which can quickly eat into your room space. However, it is the cheapest and most favoured option. This is one of the most popular types of insulation, mainly due to the fact it’s been around for so long and is widely available from most building merchants such as Screwfix, B&Q or Wickes. Being lightweight, it has a good thermal conductivity of 0.044 W/mK.
Cost: £2.96/m² (ex VAT) 100mm, £16/m² installation Disadvantages: irritating during installation, takes a lot of space.
6. ROCKWOOL INTERNAL WALL INSULATION
Rockwool wall insulation is manufactured in sheets that are pre-cut to fit between wall timber frame construction. Boards will boost thermal performance and improve acoustics. Slabs are provided in sizes that are easily transportable and good for handling measuring 1200mm x 600mm. Rockwool and Knauf are main players in the UK market. General-purpose rock wool insulation boards such as RWA45, RW5 or RW3 are perfect for internal wall applications. Range slabs include the following thicknesses:
25mm ǀ 30mm ǀ 40mm ǀ 50mm ǀ 60mm ǀ 75mm ǀ 90mm ǀ 100mm
Cost: £10.51/m² (ex VAT) 100mm, £19/m² installation Disadvantages: irritating during installation, if any moisture settles in the insulation fabric it will eventually rot.
INTERNAL WALL INSULATION INSTALLATION
There are 4 basic methods of installing internal wall insulation. The most commonly used method is the insulated plasterboard Dot & Dab method. The installation process involves nothing but plasterboard adhesive. There are no physical holes left after this installation. Sheet stays originally flat with the paper coating intact. This method uses either British Gypsum Adhesive or Knauf Plasterboard Adhesive. Generally speaking, Dot & Dab methods tend to be 3 times faster to install as it takes between three and six hours to set, which means you could carry out jointing or skimming the same day. In contrast, plaster takes two to three days to dry. Second technique of fixing insulated plasterboard is called the standard timber method. In this particular situation, you should always mechanically fix wooden battens and screw the plasterboard to battens. This technique requires plasterboard screws, plasterboard wall plugs or other fixings in order to be ready to finish.
Metal frame is also considered to be one of the quickest options to insulate your internal walls. It is built to form a partition wall, offering flexibility to the layout of the space. Steel frame method offer strength and longevity that insulated plasterboard can’t compare with. Insulating the frame and particularly over the frame as well as between the joints stops thermal transfer. This makes the building more comfortable and energy efficient for the occupants.
There is also another method that has been in use in the UK and Europe for years. In fact, has been successfully installed in 1,000’s of flats and houses by Local Authorities, Housing Associations, private Landlords and homeowners. This remarkable thermal insulation is called 10mm Sempatap Thermal Wallpaper. Thermal wallpaper works by slowing down the rate at which cold walls soak up heat energy. Consequently, it insulates rooms considerably faster, in many cases increasing warm-up times by 65%. Thanks to its thickness, expertly blended material and advanced aerospace technology, this warmth is easily maintained even in the harshest weather conditions.
Novia VC2T is an innovative waterproof and flame resistant synthetic HDPE scrim reinforced laminate for use in temporary protection applications.
It is cheaper, lighter and more practical to use than the old-style paper versions.
Protecting heavily trafficked areas, new surfaces and finishes ..
Lightweight but strong, scrim-reinforced material
Flame-resistant to EN 13501 Class E - Fully waterproof
HDPE scrim reinforced - Recyclable
Roll weight of only 9kg - Lightweight
Suitable for a wide range of temporary applications
10mm Dufaylite 3D Paper Honeycomb Ultra Board 2440mm x 1220mm is a cost-effective and sustainable solution designed for both retail signage and display or 3D applications where strength and durability are essential.
Developed to be a genuine alternative to traditional MDF, corrugated centre, foam..
10mm Fermacell Firepanel is a homogeneous fibre-reinforced gypsum based dry lining fire protection board reinforced with non-flammable fibres for superior fire protection.
Firepanel A1 is a new dimension in fire protection for dry linings, an innovative development of the original Fermacell Gyps..
10mm Fermacell Firepanel Class A1 Non Combustible Fire Protection Board
Homogeneous fibre-reinforced gypsum based dry lining fire protection board
Firepanel is reinforced with non-flammable fibres for superior fire protection
Fully complies with construction building materials class A1 non-combustible
Firepanel partition system to EN 1364-1 provides 60 minutes fire rated lining
10mm White Edging Strip is a professional self-adhesive edginig solution designed for 3D Dufaylite Honeycomb Ultra Boards.
Edging Roll is easy to apply, fully recyclable and requires no tools other than a pair of scissors.
Available in black or white on a standard 50m roll.
Made from a raw ..
110mm Celotex XR4000 PIR Insulation Board (XR4110) is an easy to cut and install multi-purpose polyisocyanurate rigid foam insulation board featuring a low emissivity foil facings that is suitable for floor, wall, roof and ceiling cut-to-fit applications.
Celotex Insulation Board is an excellent ..
12.5mm Knauf Fire Panel Plasterboard Fire Shield is a high quality gypsum based tapered edge plasterboard with additives for fire performance that is suitable for Fire Rated partitions and any other drylining application where fire rating is crucial.
Knauf Fire Resistant Plasterboard with a Pink ..
Superior Fire Protection
Partitions and Lining Systems
Plaster Finish or for direct Decoration
Plasterboard with a Pink Paper Face
Fire-Panel can provide up to 1 Hour Fire Resistance
12.5mm Knauf Moisture Panel Moisture Resistant Plasterboard is a gypsum plasterboard with water repellent additives for moisture performance that is suitable for kitchens and bathrooms and other internal areas subjected to high humidity.
Knauf Moisture Shield Plasterboard with a Green Paper Face ..
12.5mm Knauf Sound Panel Acoustic Plasterboard Sound Shield is an enhanced special gypsum tuned core acoustic plasterboard that greatly reduces any noise impact in adjacent rooms, flats, acoustic partition walls or properties.
Knauf Sound Shield Tapered Edge Plasterboard with a Blue Paper Face ha..
12.5mm Knauf Vapour Panel Foil Backed Plasterboard is a strong vapour check laminated plasterboard with a metallised polyester foil laminate on the grey colour paper back for lining external walls and roofs.
Foil Backed Plasterboard is a combination of standard wallboard and laminate with metalli..
12.5mm Knauf Standard Wallboard Plasterboard is an effective, versatile and good value standard plasterboard with an ivory paper face, ideally suited to receive a plaster finish, or for direct decoration.
Wallboard is a standard gypsum based plasterboard for general application where basic fire, ..
Siniat Weather Defence External Sheathing Board 12.5mm x 1200mm x 2400mm is a strong, moisture resistant A1 non-combustible exterior sheathing board faced with water repellent material that is compliant for structures above 18m in height.
Weather Defence™ is a revolutionary facade external sheath..
DensGlass A1 Fire Rated Sheathing Board 12.7mm is an A1 non-combustible external sheathing board that consists of a fibreglass mat with a gypsum core, designed to provide a high degree of protection from the elements in external cladding constructions.
12.7mm DensGlass Gold Sheathing Board is an ..
12.7mm Promat MONOLUX 800 (MST 800) is a robust low thermal conductivity rigid fire protection board specifically formulated without asbestos and mineral fibres for use in constructions and insulation linings.
Monolux 800 High Performance Fire Protection Board is a tough and durable, resistant to..
Monolux 800 - providing up to 240 minutes Fire Resistance
MST-800 - 1000°C - Easy to Decorate with Paints, Wallpapers or Tiles
Suitable for Plants and single skin Insulation in Ovens and Dryers
Resistant to Moisture and Chemicals - Asbestos FREE - Non-combustible
Ducts & Services Protection, Fire Door, Heat Shields, Single Skin Partitions
12.7mm Promat MONOLUX 500 Fire Board (MST 500) is a robust low thermal conductivity rigid fire protection board specifically formulated without asbestos and mineral fibres for use in constructions and insulation linings.
Monolux 500 High Performance Fire Protection Board 12.7mm is a tough and dur..
Easy to Decorate with Paints, Wallpapers or Tiles
Monolux 500 - providing up to 240 minutes Fire Resistance
Suitable for Plants and single skin Insulation in Ovens and Dryers
Resistant to Moisture and Chemicals - Asbestos FREE - Non-combustible
Ducts & Services Protection, Fire Door, Heat Shields, Single Skin Partitions
12.7mm Promat PROMATECT®-MST Fire Resistant Board is a rigid non-combustible insulation board specifically formulated without asbestos and mineral fibres used as a thermal break in process plants and as single skin insulation in ovens and dryers.
Fire Protection Board Promatect-MST 12.7mm is an e..
Promat PROMATECT®-MST A1 Fire Resistant Board 12.7mm
Effective and stable fire insulation solution for demanding applications
Good rigidity properties even when exposed to high temperatures of 1000ºC
Rigid fire insulation board with up to 240 minutes fire resistance (protection)
12mm Cembrit PB Permabase (UNIPAN) Cement Board is a fibreglass-mesh reinforced, lightweight, water-resistant cement board with tapered edges, used on external applications, such as rendering, brick slips or stone cladding.
This rigid cement and aggregate based board incorporates polystyrene bead..
12mm Cembrit PB Permabase UNIPAN Cement Board A1
External applications: rendering, brick slips or stone cladding
Tapered edges to facilitate invisible butt joint installation
Reinforced board with resistance to moisture and mould growth
A1 non-combustible reinforced, water-resistant fire rated cement board
12mm Promat PROMATECT®-250 is a mineral bound lightweight calcium-silicate fire protection board made with PROMAXON® technology, used for the fire protection of structural steel ‘H’ or ‘I’ shaped beams and columns and mezzanine floors.
Promat PROMATECT 250 is a 2500mm long by 1200mm wide calcium ..
12mm Promat PROMATECT 250 Fire Protection Board
A1 non-combustible low density calcium-silicate insulation board
PROMATECT®-250 is made with special PROMAXON® technology
Used for protection of steel structures and mezzanine floors
Provides up to 150 minutes fire protection to structural steelwork
15mm Glasroc F FireCase Fire Protection Board British Gypsum is a highly versatile, non-combustible, Class A1 and Class 0 glass-reinforced gypsum based plasterboard used mostly as part of the FIRECASE frameless structural steel encasement system, giving up to 120 minutes fire protection and in the G..
15mm Novia Double-Sided Butyl Tape is a high-quality sealing tape designed for Vapour Control Layer (VCL) installation.
This 22.5m long polyisobutylene based tape is economical and non-toxic solution.
Butyl tape is easy to install, tools are not required for application.
For use in applicat..
Vital for airtight installations
Very good adhesion properties
for Vapour Control Layer installation
Use in conjunction with Novia Metallised BOPP tape