Options to insulate the walls of your home
Up to 35% of heat in the home is lost through the walls, therefore insulating them will massively lower your energy bills.
If your home was built after 1935, the chances are you have cavity walls; these are insulated very easily by injecting them with cavity wall insulation.
Several holes are drilled in the outside of the wall, and insulating beads or wool insulation are then injected into the cavity between the two skins of brick.
If you live in an older house or you know that you have solid walls (there are some exceptions to the post- 1935 rule), the insulation process is a little bit trickier.
Basically, in this instance you need to either insulate the walls externally or internally.
Insulating internal solid walls causes a lot of disruption in the home since you need to move radiators and furniture – but probably the major reason some people decide it is not for them is because it steals room space.
External wall insulation is often the preferred insulation method on solid wall properties. You can have a plain smooth finish (any colour) or brick slips.
Both external and internal wall insulation need to be at least 100mm thick, otherwise they really aren’t going to greatly improve the energy efficiency. Making your wall 100mm thicker on the inside obviously will make the room significantly smaller, especially if you need to insulate more than one wall. Hence, you might want to consider insulating using thermal liner (sometimes referred to as thermal wallpaper) as an alternative solution.
What is Thermal Liner?
Thermal liner is basically a thin material that is used to help maintain heat in a room. It is made from wood fibres interwoven with durable textile fibres. This gives you is a very strong, flexible material that when attached to the walls is said to increase the energy efficiency of the room in question.
Does Thermal Liner increase the energy efficiency of walls?
I used the Wallrock KV600 Thermal Liner in my home but I think I need to set the scene a little. I have a pre-1900 maisonette situated in South London. It is near a fairly busy road, so buses and lorries driving by have actually caused quite a few cosmetic cracks in the ageing plasterboard of one of the bedrooms. In addition, this room genuinely gets freezing in winter, but the room isn’t massive so I was looking at keeping it warm without compromising on space. Thermal liner is definitely a compromise between solid wall insulation and loss of space, but it can be the best option for homes like mine, where space and energy use are at a premium.
Installing the Thermal Liner
Firstly the thermal liner is very easy to attach to the walls. Click on the link below to access the thermal liner hanging instructions
As recommended, I used the specially formulated Wallrock insulation adhesive to hang it on the walls; this is strong stuff and you need a lot of it but it does hold it in place (although there is a bit of holding until the adhesive sets). It is a little strange that the adhesive comes in tubs of 5kg and 10kg, but the recommendation is to use 6kg per roll of KV600 – it means that you need to go for the 10kg pack, even if you want to do just one roll, so you will have excess adhesive.
The video below shows you exactly how the Wallrock thermal liner is hung on the walls.
The KV600 is about twice the price of the normal Wallrock thermal liner, however the rolls are twice the size so each one covers an area of 15m2. The main advantage for me though is that it is a little bit thicker (4mm as opposed to 3.2mm thick), which is the key to increased energy efficiency. Once it is up on the walls you can paint over it as required.
First of all I can confirm the thermal liner does work. However much like secondary glazing versus double glazing, it does not provide the same level of energy efficiency as installing 100mm of internal wall insulation. It works though, and it is significantly cheaper. I required just under 2 rolls of thermal liner covering and with the adhesive my total outlay for the materials was just over £200. To do the same job with internal wall insulation would have cost me well over £1,000 and despite increased energy efficiency, my room would have become smaller.
One of the added advantages of installing the Wallrock KV600 Thermal Liner was its ability to cover the cosmetic cracks in the room. Now since I live on this busy road, large vehicles are going to continue to drive past my flat. The thermal liner has the ability to move very slightly so gone are the days of visible cracks in the room.
One of the things I could not accurately assess is the savings it has made on my bills. While certainly increasing the comfort of the room in question, I cannot say whether there have been significant savings on my bills – mainly because the bloody energy companies keep putting my bill up! Therefore it is impossible for me to say it will pay back within a certain timescale.However I can conclusively say it does increase the energy efficiency of the walls in my home!
As a final tip – if you are going round the corners of rooms with the thermal liner, I suggest cutting it as per the diagram below.
This ensures that the thermal liner fits more snuggly around the room!
Advantages of Wallrock Thermal Liner (KV600)
- Wallrock thermal liner is significantly cheaper than either internal or external solid wall insulation
- A noticeable increase in energy efficiency – the room certainly doesn’t get cold as fast when the heating turns off
- Wallrock thermal liner covers the cracks and ‘moves’ with the building so the room will remain crack free (fingers crossed!)
- It does a job and doesn’t steal significant square footage of the room.
Another option is AeroTherm insulation paste. Just a 1mm layer on walls can reduce heat loss from rooms by 35%.