Ever wondered why your walls stay cold even after your heater has been working for several hours? Most UK homes experience this; the reason for this is because heat keeps escaping through the walls. This is especially true in older British homes. This issue directly increases your home’s carbon footprint and is a big reason why you are getting such high energy bills.
Fortunately, there is a great way to warm up your home’s cold walls from the inside to prevent heat loss. This is often the best and cheapest option, especially for homes with solid walls or where external wall insulation isn’t possible. This in-depth blog will help you understand why your walls are cold and how to make them warm and use less energy.
Why do my walls feel so cold? How Heat Loss Happens
Walls are cold because they are not insulated from the inside properly. Older homes, like those with “stretcher-and-header” brickwork, have strong walls. Newer homes, on the other hand, usually have a space between the inside and outside walls that can be filled with wall insulation. These solid walls don’t hold heat well, so heat can easily escape, which makes the inside of the wall feel cold to the touch.
There are a few things that can make walls cold besides the way they are built:
Bad Ventilation: Air can get stuck if there isn’t enough ventilation, which can cause cold spots and moisture to build up.
Problems with Moisture: Walls that are wet from condensation, leaks, or rising damp get even colder, which can make insulation less effective.
Thermal bridging: This happens when a part of the building that isn’t well insulated, like a window frame or joist, lets heat escape, leaving a cold spot on the wall.
The first step to finding the best solution is to figure out what caused the problem.
Signs Your Home’s Inside Walls Need Insulation
You can’t just touch something to see if it needs insulation. If you see these signs, your home would benefit from having insulation in the walls:
Rooms feel cold: If you have the heat on but the rooms are still cold all the time, it’s likely that your walls are letting a lot of heat escape.
High energy bills: One of the easiest ways to tell if your insulation isn’t working is if your heating costs go up but your comfort doesn’t.
Mould & Condensation: When the walls of a room are cold, warm, humid air will condense on them, making them damp, mouldy, or condensing. This can make your lungs very sick, and it’s a great place for black mould to grow.
Draughts: You might feel a cool, light breeze coming in through the edges of windows, walls, or outlets.
Why insulating the walls inside is better than other options
Insulating the walls of your home has many benefits besides just keeping it warmer. There are a lot of other good reasons to insulate the walls inside your home, such as
High yearly savings: If you can keep heat from escaping through your walls, your energy bills will go down a lot. Depending on the size and style of your home, this could save you between £140 and £700 a year.
Better Comfort: Getting rid of cold spots and draughts will make rooms feel warmer and cosier for longer.
Reduce your carbon footprint: using less energy will make your home better for the environment because your heating system will release fewer greenhouse gases.
Better Energy Performance Certificate (EPC) Rating: A home with a higher EPC rating will be more appealing to people who want to rent or buy it, and it will also be worth more.
Insulating the inside of your home without changing the outside is a great idea for historic homes or homes in conservation areas. It looks good and is useful.
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Best methods to insulate a cold wall from the inside
Picking the right kind of insulation is very important. What you should do depends on the kind of wall you have, how much money you have, and how much space you are willing to give up.
I. Insulated plasterboard
Insulated plasterboard is a common and simple way to do it. The inside of the wall is glued directly to the rigid insulation boards.
Pros: It doesn’t take up much room and is easy to put together.
Cons: It might not work well on walls that are very uneven, and it doesn’t stop thermal bridging as well as some other options.
II. Stud Wall with Insulation
A stud wall with insulation is built a few inches away from the wall that is already there. A stud wall is a frame made of either metal or wood. After that, the empty space is filled with the insulating material of your choice.
Pro: It has great thermal performance because it stops thermal bridging very well. It also makes a brand-new, flat surface that is perfect for a new finish.
Cons: It might take longer to put up and needs more room than insulated plasterboard.
III. Insulation of Spray Foam
In this type of insulation liquid foam is sprayed onto a wall. The foam then expands to fill in any gaps and form an airtight panel.
Pros: It creates a barrier that is completely sealed, getting rid of all air and heat gaps.
Cons: It might cost more, and a pro needs to put it in. Also, if the wall gets wet a lot, it can hold water because it doesn’t let air through.
IV. Thermal-efficient coating:
These are special plasters or spray-on insulation materials, like cork, that keep heat in or out.
Pros: They save space in the house because they are so much thinner than regular boards (as little as 8 mm). They let air flow through and can make things much less damp, which is why they are great for older buildings.
Cons: They might not keep heat in as well as full-stud walls or thick, rigid boards.
V. Batten Wall Insulation
When you batten wall insulation, you insert wooden battens on the wall in a vertical or horizontal pattern and then fill up the gaps with insulation materials like foam boards or mineral wool. It’s ideal for walls which are not straight or are old.
Pro: It wipes out the surface for finishing and provides you a lot of insulation choices.
Con: The batten framework takes up a lot of space in the room.
VI. Rigid Foam Boards
PIR and EPS are two forms of materials that can be used to manufacture rigid foam boards. They are great at keeping heat in, so you can put them between battens or behind plasterboard.
Pro: It insulates quite well, even in thin layers.
Con: It fails to allow air to circulate, and if it isn’t placed in with outstanding ventilation, it can hold moisture.
Common Insulation Materials for Stud/Batten Walls:
- Mineral wool: It is a cheap option and often recognised for its ability to not catch fire easily. It comes in rolls or batts.
- Natural Materials: Cork, hemp, and sheep’s wool are all good choices that are good for the environment, last a long time, and let air in. In older homes with solid walls, they look great.
- Foam Boards: Polyisocyanurate (PIR) and phenolic foam are two materials that are used to make rigid foam boards. These boards have a very high thermal efficiency for how thick they are, but they might not let as much air through.
Survey of interior wall installation
You need to be organised to install it correctly, whether you do it yourself or hire someone else to do it.
Get the wall ready.
Check the wall for mould, water damage, or cracks in the structure before you start. You have to find and fix any problems with moisture completely. Make sure the wall is as dry and level as possible after you clean it and take off any plaster or wallpaper. Putting insulation over a wet wall is very important because it will keep water in and hurt the wall a lot.
Choose Method and Materials
Choose the best insulation for your home based on how it was built, how much space you have, and how much money you have. Materials that let air pass through are often best for solid walls. You have more options for a modern cavity wall that you insulate from the inside.
Preparation
After you cut the insulated plasterboard to the right size, use a special glue to stick it directly to the wall. Make sure that every edge and joint fits together well.
Make a frame out of wood or metal for stud walls. Check to see that it’s straight and level. You have to be careful when putting the insulation into the frame after cutting it to size.
Barrier to keep moisture out
This is something that a lot of people forget. There is a vapour barrier on the side that keeps you warm. The cold wall outside can’t get to the warm, damp air inside the room, where it could freeze and hurt the insulation or mould.
Finish
After you put in the insulation, you need to tape or foam all the seams and edges to keep the heat in. Put paint or wallpaper on top of the insulation to get the look you want.
Be careful of “cold bridges”, which are places where the insulation doesn’t go all the way to the floor, ceiling, windows, or doors. A good worker will know how to keep the heat in these places.
How to Get Free Insulation for Your Interior Walls
A lot of people think that making their home more energy efficient by insulating the inside walls is too costly and not possible. We have good news for you, even though it can cost between £4,000 and £12,000 for insulation of interior walls of your house.
We can help qualified homeowners get this service for free. In other words, you don’t have to worry about how much it will cost to make your home more energy-efficient and warmer.
Government Grants for Internal Wall Insulation
The UK government is working on their vision 2050, which aims to make the UK a net zero carbon-emitting nation and make homes more energy efficient with programmes that include free internal wall insulation schemes. These internal wall insulation grant programmes work with certified installers like CO2 Reduction to provide professional insulation services for free or at very little cost to homeowners that meet the government’s eligibility criteria.
- Energy Company Obligation Scheme: This scheme requires energy suppliers to help low-income, fuel-poor, and vulnerable households by installing wall insulation to help them reduce energy bills.
- Great British Insulation Scheme: Under this scheme many households in England, Wales, and Scotland get free or low-cost internal wall insulation. This scheme is open to all homeowners, landlords, and private tenants. Eligibility is based on factors like EPC ratings or specific Council Tax bands.
- Warmer Homes Scotland Scheme: This scheme can cover costs for several energy improvements for eligible households in Scotland. It usually targets specific criteria like age, income, and benefits.
- Affordable Warmth Scheme (Northern Ireland): Helps low-income households with energy efficiency improvements in private accommodations.
Common Mistakes to Avoid
Wet Wall: If a wall is already wet, don’t add insulation on it before drying it completely.
Vapour Barriers: If you ignore vapour barriers, mould can grow, condensation problems can get worse, and your new insulation can get damaged.
Gaps: If you fail to fill in any cracks in the insulation, thermal bridging will happen, which will make it work much less well.
Wrong Materials: Choosing materials can be tricky, as materials that don’t let air flow easily can make things worse again, especially in older homes. Always get advice from a professional on what material you should use.
Not thinking about ventilation: insulating a house makes it less airtight. To keep moisture from building up, make sure there is enough airflow.
The UK’s laws and rules about building
Part L of the Building Regulations says that insulation for internal walls in the UK must meet certain energy efficiency standards. You have to insulate more than 25% of a wall if the work has a U-value of 0.3 W/m²K or less, which is a standard for thermal performance.
Before you start a big DIY project, you should call your local government’s building control department to make sure you are following all the rules.
FAQs
Will insulation get rid of the mould in my house?
Adding insulation to the inside walls of a building can stop mould from growing because of condensation. But it won’t get rid of mould that grows because of leaks or water that rises.
How thick should the insulation be?
The thickness varies by material, but it’s usually between 50 and 100 mm. The UK Building Regulations say that the U-value should be 0.3 W/m²K.
Does it make the room bigger or smaller?
Even the thinnest insulation will make the room’s floor space a little smaller. You give up some comfort for a little less space.
