Without cavity wall insulation, up to 35% of your home's heat can escape through the walls- taking your money with it. Not only is your home colder but your heating system has to work harder, leading to higher energy bills. Insulating your cavity walls can cut heat loss by as much as two-thirds.
Cavity wall insulation can keep your home warmer in the winter and cooler in the summer. It's not just about keeping a warm house in winter, but also about preventing your home from overheating in summer.
This means that there will be a moisture build up in your walls. The moisture will transfer to your cavity insulation, and damp and mould will begin to develop inside your walls. This really does become a hindrance for you when the mould starts growing inside your home, and damages your things.
In a cavity wall, the outer leaf is colder than the inner, especially if it is well insulated. Moisture vapour diffuses and permeates from inside the house and will condense when it reaches the outer leaf, if the outside is cold enough.
How many degrees of difference insulation makes on its own depends on the type of home you have, what the weather is like and what kind of insulation you have. Depending on what you choose, you could see a five- to 20-degree temperature difference just based on the insulation alone.
In an uninsulated home, roughly one-third of the heat loss occurs through the walls. Proper cavity wall insulation can significantly cut down on energy waste and reduce heating costs. According to the Energy Savings Trust UK, this upgrade could save you between £110 and £470 annually on energy bills.
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
How heat escapes from your home. If you're asking yourself Why is my house so cold even with the heating on? or Why is my house not staying warm?, the truth is that air leaks—along with insufficient insulation—cause heat to escape directly from your home.
Properties without a DPC, or where the DPC is too low (typically less than 125mm from the ground) and a French drain has not been installed. Some properties with raked mortar joints. Properties with a cavity wall under 50mm or over 150mm. Properties that have significant rubble or mortar ingress in the cavity.
The signs of cavity wall insulation failure could be as simple as noticing patches of dampness on external walls or could be recognising that the installation isn't delivering the energy-saving benefits it should.
Here are some common types of cavity wall insulation and their approximate lifespan: Mineral Wool Insulation: 25 to 30 years. Foam Insulation: 20 to 25 years. Bead Insulation: 30 to 40 years.
Two options are available for non-cavity walls: external insulation (around £12,000) and internal insulation (about £7,500). While expensive, government schemes like the Great British Insulation and ECO4 offer grants to help low-income households improve their homes' energy efficiency.
Poorly installed insulation is now causing damp and or cold spots internally. The insulation has become defective or is unsuitable. The insulation has got wet due to the property being poorly maintained. The insulation has suffered water damage due to a flood or fire.
Is it worth topping up cavity wall insulation? Topping up your cavity wall insulation can be beneficial, especially if the existing insulation has settled or degraded over time. Often this can happen with certain materials like expanded foam or polystyrene beads.
Cavity walls lose less heat than solid walls and are much easier to insulate.
Whilst cavity wall insulation itself does not require any maintenance, as with any building, failure to properly maintain the fabric of your house, inadequate ventilation or a lack of heating may result in problems with dampness.
Check Your Wall Insulation Level
Remove the outlet cover and shine a flashlight into the crack around the outlet box. You should be able to see if there is insulation in the wall and possibly how thick it is. Pull out a small amount of insulation if needed to help determine the type of insulation.
If you're cold even though your thermostat indicates you shouldn't be, your furnace likely isn't the problem. In most cases, it's working just fine. It's your home that needs attention. Lack of insulation, severe air leakage, and/or unbalanced ductwork are frequently to blame.
What causes cold walls? Poor insulation is the main reason why walls feel cold, especially in older properties with solid walls. Roughly 35% of heat loss is through walls and gaps, in and around windows and doors. Walls transfer heat and the warmth from your home will escape outside if your walls are poorly insulated.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space. While you might think that too much insulation can't be bad, there are some significant consequences to consider.
Leaving Too Many Gaps
One of the biggest problems DIY homeowners face is leaving too many gaps in their insulation. Gaps or insulation that isn't secured correctly can leave the building structure open to air and moisture leaks. Spray foam insulation is best for reaching into small cracks and any areas left open.
Walls, floors and ceilings should feel warm and dry to the touch in your home. An indication that there is not enough insulation can be drywall or paneling feeling damp or cold. Conversely, the walls outside of your home should feel cold because insulation stops the heat from escaping.