Your Questions

Cavity Wall Insulation

  1. How much will cavity wall insulation cost?
  2. How is cavity wall insulation installed?
  3. Doesn't it make a mess?
  4. How are the holes filled?
  5. My house is rendered, won't cavity wall insulation mess up the render?
  6. How long does it take to install cavity wall insulation?
  7. How can I arrange a survey and quote?
  8. Doesn't cavity wall insulation cause damp?
  9. If my house was built with a cavity, surely it's there for a reason?
  10. How do I know if I've got cavity walls or solid walls?
  11. Can I install cavity wall insulation myself?
  12. My house is semi-detached/terraced and my neighbour(s) doesn't want cavity wall insulation. Can you still insulate my walls?
  13. I've got a timber framed house - can I still have cavity wall insulation?
  14. I live in a flat on the 10th floor of an apartment block, can I get cavity wall insulation?
  15. How can I tell if my new home's previous owners have already insulated the cavity walls?
  16. What guarantee of workmanship should I look out for in a cavity wall insulation installer?
  17. Are there grants available for cavity wall insulation and are there strict criteria as to who is eligible, like with loft insulation?

    18. Solid Wall Insulation

  18. I have loft insulation but would like to do more to make my home more energy efficient. I know about cavity wall insulation, but my home has solid walls. Can I insulate these?
  19. I'd like to make my period home more energy efficient, but will internal wall insulation ruin my original features, and will I lose floor area?
  20. Are there any grants available for installing solid wall insulation?

    21. Loft Insulation

  21. How much will loft insulation cost?
  22. How much loft insulation do I need?
  23. How do I find out how much loft insulation I have?
  24. I have lots of rubbish in my loft. Do I need to clear it out or will the installer do this for me?
  25. I want to use my loft for storage, how can I do that if it is insulated to the depth recommended?
  26. How long does it take professionals to install loft insulation?
  27. How long would it take me to insulate my loft?

    28. Building Regulations

  28. Why wasn't my house built with cavity wall insulation and the right amount of loft insulation?

    29. Subsidies

  29. Is it true that everyone in the UK is entitled to subsidised insulation?
  30. I live in a rented property, can I still get my walls and loft insulated?
  31. OK, I'd like to get my walls and/or loft insulated, what do I do now?

    32. Thinkinsulation

  32. What is Thinkinsulation??
  33. How can insulating my house help solve Global Warming and Climate Change?
  34. What benefit will insulating my house give me and my family?
  35. I make sure my energy comes from Green sources, like wind and solar panels - surely I don't need to insulate my home to help the environment?

Q1. How much will cavity wall insulation cost?
A1. The cost depends on the size of your house, however, with subsidies, it will usually cost around £250. However, it can save up to £115 a year, so can pay for itself in approximately 2 years.
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Q2. How is cavity wall insulation installed?
A2. Small holes of about 20mm in diameter are drilled about 2 metres apart in the external brick wall where the horizontal and vertical mortar joints meet. Insulation is then blown along a flexible hose into the cavity through these holes.
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Q3. Doesn't it make a mess?
A3. No. All work is carried out externally through small holes in the brickwork joints. A small amount of dust is created when the holes are drilled. The cavity wall insulation is then blown into place using a hose, straight into the wall, so there is no dust or spills.
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Q4. How are the holes filled?
A4. The holes used to inject the insulation are filled with matching mortar and are barely noticeable.
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Q5. My house is rendered, won't cavity wall insulation mess up the render?
A5. The holes drilled to inject the cavity insulation are only about 20mm in diameter and are filled with mortar after the insulation has been injected. The installer will match the existing render. If the render is painted, the filled holes should be touched up with matching paint when the mortar has dried.
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Q6. How long does it take to install cavity wall insulation?
A6. Most homes can be insulated in about 3 hours, but larger houses may take a whole day.
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Q7. How can I arrange a survey and quote?
A7. Ring Thinkinsulation on 08700 612 216 or click here to request a survey and quote.
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Q8. Doesn't cavity wall insulation cause damp?
A8. No. Extensive tests have shown that Knauf Supafil cavity wall insulation does not allow water to pass across the cavity. Supafil cavity wall insulation also contains a water repellent. Before installing the insulation, the empty wall cavities are inspected for obstructions with a special tool called a boroscope. Any obstructions are noted and cleared by the installers before the insulation is injected.
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Q9. If my house was built with a cavity, surely it's there for a reason?
A9. The purpose of the cavity is to prevent rain that soaks into the outside brickwork from crossing to the inside of the wall. The cavity interrupts any water that soaks through the brickwork and drains it to the bottom of the wall where it drains to the outside. Injecting mineral wool insulation into the cavity still allows water to drain to the bottom of the wall. Knauf Supafil cavity wall insulation contains a water repellent and so does not absorb water. Extensive tests have shown that Knauf Supafil cavity wall insulation does not cause water to pass across the cavity.
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Q10. How do I know if I've got cavity walls or solid walls?
A10. Most cavity walls are indentified by two factors.

1. They are about 10 1/2" to 12' (270mm - 300mm) thick overall (You can measure this at a door opening).
2. All the bricks visible on the outside of the wall are all 9" (225mm) long (except at corners and openings).

Solid walls have repeat patterns of 4" (100mm) wide bricks as well as 9" (225mm) long bricks over the main area of the wall. The walls are usually a little over 9" (225mm) thick, although in larger properties the walls can be 13 1/2" (330mm) thick.
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Q11. Can I install cavity wall insulation myself?
A11. No. This is because specialist equipment is needed to install the insulation into the cavity and it's important that the cavity is fully filled with the correct density of insulation. This is why only trained and approved installers are used so that a guarantee can be given.
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Q12. My house is semi-detached/terraced and my neighbour(s) doesn't want cavity wall insulation. Can you still insulate my walls?
A12. Yes, your house can still be insulated. The installer will need to form a hole at the top and bottom of the wall to insert a spacer at the junction between the two houses. This prevents insulation being blown into the cavity of your neighbour's house.
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Q13. I've got a timber framed house - can I still have cavity wall insulation?
A13. Sorry, but it's not possible to inject cavity wall insulation into timber framed houses.
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Q14. I live in a flat on the 10th floor of an apartment block, can I get cavity wall insulation?
A14. Sorry, but it's not practical to insulate a single flat in a block. If the property has cavity walls, the whole building should be insulated.
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Q15. How can I tell if my new home's previous owners have already insulated the cavity walls?
A15. If a house was built within the last ten years, it probably already has cavity wall insulation, which may have been installed as slabs of insulation when the walls were built. You should have received a certificate or some form of documentation when you bought the house if it already has cavity wall insulation, so if you weren't given one, chances are the walls need insulating. If you don't have a certificate, though, click here to arrange a cavity wall insulation survey free of charge.
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Q16. What guarantee of workmanship should I look out for in a cavity wall insulation installer?
A16. Cavity wall insulation installers can sign up to a professional code of practice, such as those provided by the Cavity Insulation Guarantee Agency, which guarantees the work for 25 years. The installer should carry out post-installation checks on both the inside and the outside of the property, and you will be asked to sign a form to show you are happy with the work. Click here to arrange a free cavity wall insulation survey by a registered installation professional.
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Q17. Are there grants available for cavity wall insulation and are there strict criteria as to who is eligible, like with loft insulation?
A17. The cost of insulating your cavity walls has never been lower, as it can be subsidised through the CERT (Carbon Emissions Reduction Target) available from large energy suppliers, which brings the cost down to around £250. This means you'll get a return on investment in around two years' time as it can save up to £115 a year on energy bills. Homeowners can apply for a subsidy from any of the energy suppliers regardless of whether they supply a home's energy or not! Speak to your energy supplier about what grants and offers are available.
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Q18. I have loft insulation but would like to do more to make my home more energy efficient. I know about cavity wall insulation, but my home has solid walls. Can I insulate these?
A18. Solid walls actually lose even more heat than cavity walls - up to 45 per cent! Solid wall insulation - fitted to either external or internal walls - could reduce the carbon dioxide emissions associated with your home by around 2 tonnes of carbon dioxide a year, making it one of the most impactful changes that can be made to a home. If all homes with solid walls in the UK were insulated properly, it would slash the nation's carbon footprint by around 16 million tonnes annually. Insulating solid walls can reduce energy bills by a whopping £400 a year - forever - so the investment is well worth making for significant long term savings. It needs to be carried out by a professional installer, so click here to arrange a free survey and help you decide what's best for your home.
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Q19. I'd like to make my period home more energy efficient, but will internal wall insulation ruin my original features, and will I lose floor area?
A19. Internal wall insulation is a fantastic solution for period properties or listed buildings that would require planning permission for any changes made to the outside, or where the owner wants to maintain the authentic exterior appearance of the property. You don't need to worry about losing your original features or significant amounts of floor space, though. Modern internal wall insulation systems are extremely slim, yet ultra-efficient, and lead to minimal loss of usable floor area.

Installing internal wall insulation does mean that fittings such as plug sockets and skirting boards need to be repositioned, so you'll need to make sure that any decorative features like cornicing or picture rails are carefully removed and refitted following the installation. You could reduce the annual carbon dioxide emissions associated with your home by around 2 tonnes and save £400 per year on your energy bills by insulating solid walls.
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Q20. Are there any grants available for installing solid wall insulation?
A20. Although there are currently no nationally available energy efficiency grants for solid wall insulation, a number of local schemes exist to encourage households to improve their energy efficiency, which may include improvements to solid walls. Check with your local council to see if home insulation is covered by any of their renovation or home improvement grants.
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Q21. How much will loft insulation cost?
A21. The cost depends on the size of your house, however, with subsidies, it will usually cost around £250-350 to install yourself – which can pay for itself in around 2-3 years.
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Q22. How much loft insulation do I need?
A22. To meet current Building Regulations you need 270mm of mineral wool insulation. 100mm between the ceiling joists and 170mm laid over the joists.
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Q23. How do I find out how much loft insulation I have?
A23. Simply push a tape measure or ruler down the side of a piece of loft insulation until it hits the plasterboard ceiling and read off the depth.
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Q24. I have lots of rubbish in my loft. Do I need to clear it out or will the installer do this for me?
A24. Yes, you will need to clear the roof of any rubbish or stored objects before the insulation is installed.
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Q25. I want to use my loft for storage, how can I do that if it is insulated to the depth recommended?
A25. You or your installer can also lay innovative loft boards called Space Board along with a chipboard deck to provide storage space. click here to view. These are insulation boards made from Polyfoam extruded polystyrene designed to be placed on top of the ceiling joists instead of the 170mm mineral wool insulation. You will need a loft hatch which is minimum 600mm x 600mm.
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Q26. How long does it take professionals to install loft insulation?
A26. It takes about 2 hours for an average sized loft.
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Q27. How long would it take me to insulate my loft?
A27. Allow about half a day once you have bought the insulation. Remember - you will need one layer of 100mm between your roof joists if you don't have any insulation, then a second layer of 170mm on top (cross layered) to comply with current building regulations. Measure the area of your loft and look at the packaging label for the area contained in a roll.
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Q28. Why wasn't my house built with cavity wall insulation and the right amount of loft insulation?
A28. Houses comply with the building regulations that apply at the time the property is built. Since the oil crisis in the early 1970s, the insulation standards in the Building Regulations have been progressively upgraded click here to view. The Government plan to increase insulation standards again in 2005, and this is unlikely to be the last change. So, most homes need extra insulation to keep up with current insulation standards.
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Q29. Is it true that everyone in the UK is entitled to subsidised insulation?
A29. Yes, everyone is entitled to a subsidy and some people can even have free installation. Why? Because the UK Government is obligated to reduce greenhouse gas emissions by 2010 as part of the Kyoto Protocol. One of the easiest ways to achieve a large reduction in greenhouse gas emissions is through increased home energy efficiency. The Government has stated that cavity wall insulation and loft insulation are the most effective methods which is why they have legislated for power/energy utilities and power companies to provide subsidies.
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Q30. I live in a rented property, can I still get my walls and loft insulated?
A30. Yes, people living in rented property can get their homes insulated, but you must get the permission of the owner or landlord.
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Q31. OK, I'd like to get my walls and/or loft insulated using Government subsidies, what do I do now?
A31. It's easy! Ring Thinkinsulation on 08700 612 216 or click here to request a survey and quote.
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Q32. What is thinkinsulation?
A32. Thinkinsulation is an initiative jointly supported by the Energy Saving Trust and Knauf Insulation. The aim of thinkinsulation is to increase public awareness of the benefits of insulation and how it contributes to solving global warming and climate change. thinkinsulation can also arrange free no obligation surveys and quotes for subsidised cavity wall and loft insulation via power/energy utility companies, using certified installers and high quality, warranted insulation products.
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Q33. How can insulating my house help solve Global Warming and Climate Change?
A33. Well insulated houses use less energy to keep them warm. This means that less carbon dioxide, a greenhouse gas, is released into the atmosphere from burning of fossil fuels (coal, oil and gas) in our power stations and central heating boilers. Global warming is occurring because large volumes of greenhouse gases - including carbon dioxide - are accumulating in the Earth's atmosphere. This causes the planet's average air and ocean temperatures to increase and sea levels to rise, resulting in increasingly severe weather conditions. This effect is called climate change and it's already happening. By improving the insulation of your home, you will be playing your part in reducing the effect of global warming.
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Q34. What benefit will insulating my house give me and my family?
A34. Insulation has many benefits:

1. Your home will be warmer and more energy efficient.
2. Your should make savings on your heating bills.
3. Your heating system will emit less carbon dioxide, the greenhouse gas that causes Global Warming.
4. Glasswool insulation will also reduce outside noise and increase resistance to fire.
5. Glasswool insulation is made with recycled glass and is a sustainable product which is light on the earth's resources. It was awarded an A rating in the BRE's Green Guide. Requiring no maintenance, glasswool will last indefinitely and can even be recycled and reused again if removed from a building.
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Q35. I make sure my energy comes from 'Green' sources, like wind and solar panels - surely I don't need to insulate my home to help the environment?
A35. Well done for using energy from green sources. Renewable energy sources, like wind power, produce electricity and solar panels are part of the solution if we are to reduce emissions of greenhouse gases and tackle climate change. Although solar panels are good for providing hot water, they do not produce water that is hot enough for central heating. Most homes are heated by gas or oil, and when it's burnt in your boiler it emits carbon dioxide, a greenhouse gas. By improving the insulation of your home, you will be reducing your energy consumption and therefore playing a greater part in reducing the effect of global warming.
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