Pros and Cons Of Fibreglass Insulation
Fibreglass insulation is what you might call ubiquitous. When we think of the insulation that is in our lofts, ceilings, and even our walls, we imagine the rolls of (often pink) batts that look a little like spun sugar or candy floss. In this article we will run through the pros and cons of fibreglass insulation
In fact, it is spun glass and sand, and while it has excellent insulating properties, it isn’t always the best choice for insulating your home. Here we detail that pros and cons of fibreglass insulation, and propose a more cost-effective choice to consider…
The government has set a target of 80% reduction in carbon emissions in the UK by 2050, and as part of this policy, they encourage the insulation of our homes.
With around 38% of UK homes (that have a loft) having less insulation than they need (125mm rather than 270mm), the insulation already in place is proving ineffective, making it imperative that we should all improve our insulation for the government to meet their targets.
Fibreglass insulation is playing a part in that role, although in contrast to other materials, its long-term performance leaves a lot to be desired.
What Is Fibreglass Insulation?
Fibreglass insulation is a man-made product that is made of very thin glass fibres and was first developed for use in the home in the 1930’s. In particular it became popular when it was discovered that another excellent insulator, asbestos, was harmful to our health.
Despite its make up, and the energy-heavy way in which it is manufactured, fibreglass insulation was a great alternative to the cancer-causing asbestos used to that point.
Fibreglass insulation works in the same way as other insulation – by trapping escaping heat within its structure. Because of the way it is spun, the glass fibres are surrounded by air.
This is the case whether it is formed into batts or rolls or if it is left loose as a blown insulation.
These air pockets offer a barrier to the escape of warm air, and they slow down the travel of noise as well. It is essential that these air pockets remain intact and dry, to ensure the effectiveness of the insulation.
Fibreglass is incredibly easy to install, and can be carried out as a simple D.I.Y job. This is what makes it one of the most popular insulation products for householders to buy for themselves
Fibreglass Insulation: The Advantages
● It is often made from recycled glass, and this makes it a product that is good for the environment and a useful way to use products that are readily recycled. As a glass product, even the percentage that is not recycled, is made from sand, making it a great renewable option.
● It is fireproof and therefore is a great option for walls that run between homes, for ceiling insulation, and for around light fixtures and other electrical items. However, the covering that is often used as a vapour barrier may not be fireproof.
● It does not shrink, and its structure will not collapse readily. Due to the way fibreglass insulation is structured, it has many air pockets and these maintain its shape in the long term.
● It is a great option for blown insulation, as it offers a more consistent layer due to the way it settles, with plenty of air pockets.
● It is incredibly easy to install, and can be carried out as a simple D.I.Y job. This is what makes it one of the most popular insulation products for householders to buy for themselves.
● It is an excellent insulator, and can reduce energy bills by more than £240 per year for the average home when used in the loft.
● It is an excellent acoustic insulation, and can reduce the noise travelling through your home.
Fibreglass needs at least 270mm of thickness in the average loft to get a suitable insulation r-value; this can make it very difficult to lay a floor in the loft, or to maintain head height
Fibreglass Insulation: The Disadvantages
● The tiny slivers of glass used in this product can be harmful to the skin and if inhaled. For this reason, it is often coated in a vapour barrier. Care must be taken when installing it, with masks and gloves worn for protection. If laid in the loft, it should be covered by boards and not touched.
● If it becomes wet, it loses its insulation qualities, making it ineffective. This can happen if the product becomes directly wet (ie if there is a leak in the roof), or if it is affected by condensation. Once wet, fibreglass condensation cannot dry out and will need to be replaced. You may also find that damp insulation will become mouldy, or that mould will grow elsewhere in the room.
● It can be difficult to fit batts into smaller spaces and unusual or awkward gaps. While it can be cut to size quite easily, there are always gaps between each batt and around the edges. It is very difficult to eliminate these completely.
● It can be a cosy place for rodents and other unwelcome home visitors to set up a nest in. They will not eat the product, but it is warm and cosy.
● It can sag over time, and therefore loses its ability to work well. This is especially the case when it is used inside walls or on rafters. Over a few years it can sag, fall out and collapse, leaving gaps where air can penetrate.
● It needs to be laid with a vapour barrier, or it should be vented to prevent moisture buildup. Due to the way that this insulation works, it can prevent air flow, causing a buildup of condensation, and requires a venting system to work effectively.
● It needs at least 270mm of thickness in the average loft to get a suitable insulation r-value; this can make it very difficult to lay a floor in the loft, or to maintain head height.
● It should be kept in mind that fibreglass can melt at high temperatures, and this can happen during a house fire.
If you are looking for a product that is cheap and easy to install, go for fibreglass insulation, but don’t forget that it can cause issues with damp and that it may not offer the insulation qualities and R-values that you expect. Spray foam insulation may be a better choice, and give you the robust solution that you want
Insulation Options: The Spray Foam Solution
One of the best insulation types is spray foam insulation, that is used on the rafters of your roof. This fixes many of the problems that you may find with fibreglass insulation, and still has many of the advantages.
While it is a product that must be installed by a professional and is somewhat more expensive, it offers better insulation qualities based on the depth of application, and it can work its way into all nooks and crannies – something fibreglass simply cannot do.
Spray foam insulation is a foam that expands many times its original size, allowing it to work its way into even the most awkward space.
This makes it an excellent choice for spaces such as lofts, where the roofline poses problems with uniform-sized fibreglass batts.
Wool insulation (including sheep’s wool and mineral wool), offer similar properties to fibreglass insulation, although sheep’s wool reacts well to water and does not lose its effectiveness. It is significantly more expensive however.
Fibreglass insulation is an excellent way to add to the insulation in your home and it does a very effective job, but when choosing the right insulation for your needs you should consider both the pros and the cons of your choices.
If you are looking for a product that is cheap and easy to install, go for fibreglass insulation, but don’t forget that it can cause issues with damp and that it may not offer the insulation qualities and R-values that you expect. Spray foam insulation may be a better choice, and give you the robust solution that you want.
Seeking out an insulation solution that stands the test of time? Spray foam performs for the life of the building-and offers you year on year savings. Take the first step to driving down your bills today, by calling 0800 1700 636, or by simply clicking the button below!