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How Long Does Attic Insulation Last?

How Long Does Attic Insulation Last

We all know the benefits of installing insulation into our attics and lofts, however, if that insulation only lasts a few years and needs replacing in a short space of time, your choice may not seem such a great idea after all.

This is especially the case if your improvement on energy costs has not yet paid off the cost of the installation.

There are two questions you need to ask when choosing your insulation: How long will my insulation last, and will I pay it off through reduced energy costs during that period of time?

Then you need to consider if the insulation will become less effective over time – giving you yet another calculation to bear in mind. Hopefully we can answer some of those questions here.

The Energy Saving Trust estimates that an average detached home with insulation added to the attic (at a depth of 270mm or the equivalent) will reduce its energy costs by £240 per year.

All types of insulation are designed to last long enough to easily pay off their installation costs, and with such a great reduction in energy costs, this is hardly surprising. However, some will take longer than others, as the following article reveals…

How Long Does Attic Insulation Last

In recent years, it has been recommended that all homes have at least 270mm of insulation (or the equivalent to achieve the correct R-value). Before this, insulation was often added to just 100mm of the depth of the rafters or floor joists

But My Attic Already Has Insulation!

It is worth noting that your insulation will last a very long time, but only when it is correctly installed, and in ideal conditions. This means that it is not affected by any of the following factors, that could cause the insulation to become less effective over time:

● Damp or mould or the product becoming wet in any way
● Direct sunlight
● Rodents or other infestations
● Compaction by flooring or possessions or even naturally over time
● Dirt and dust that clogs its air pockets

Most homes will be very lucky to avoid any of these complications, so it may be wise to take the recommendations regarding effectiveness and longevity with a pinch of salt.

You may be assuming that because your insulation still looks OK it is suitable for today’s standards. If it was installed more than ten years ago, this is unlikely.

In recent years, it has been recommended that all homes have at least 270mm of insulation (or the equivalent to achieve the correct R-value). Before this, insulation was often added to just 100mm of the depth of the rafters or floor joists.

This means that many homes are under insulated, and will therefore need topping up, or new insulation added.

How Long Does Attic Insulation Last

Made from cellulose or mineral wool, this type of insulation will also last as long as 100 years – but is prone to settling and compacting. It is also often used as a home to rodents, that can leave it ineffective and damp

Attic Insulation: 3 Main Options On Offer

Attic Insulation Option No.1: Mineral Wool Insulation

Most types of wool type insulation become immediately ineffective if they become damp and simply have to be replaced. If your loft is damp or has a leak, you will need to replace any affected insulation.

Wool insulation tends to become compacted over time and will not work as well. This is especially the case if it is underneath floor boards, or is used for the storage of boxes.

Mineral or glass wool is a cheap product, and an entire loft can be insulated for around £350. This makes it the fastest when it comes to payback. You will have the installation paid off within 2 years, but you may wish to replace it if it becomes damaged.

Attic Insulation Option No.2: Sheep Wool Insulation

Sheep wool insulation is one product that can withstand damp conditions, and is a good option for homes with leaky roofs, or where you are aware that the loft is likely to become damp.

However, sheep’s wool is a natural product with a shorter life span as it does naturally break down, and start to decompose. As a more expensive product, it may take several years to make your money back on sheep’s wool insulation.

Attic Insulation Option No.3: Blown In Insulation

Made from cellulose or mineral wool, this type of insulation will also last as long as 100 years – but is prone to settling and compacting. It is also often used as a home to rodents, that can leave it ineffective and damp.

This type of insulation should be checked every few years to ensure it is still working well, and covering the area to the correct depth. It is also prone to issues resulting from roof leaks.

This type of insulation can be paid back within 2-3 years – however it may need replacing sooner than other options.

How Long Does Attic Insulation Last

It is true that spray foam insulation is more expensive than other options, but even thicker applications can be paid back within a few years, and the longevity of the product means that you can trust you won’t need to replace it within your lifetime

Attic Insulation: Why Spray Foam Does It Better

It is thought that spray foam can last as long as 80 years before it needs to be replaced – however as it is a relatively new product, this lifespan is yet to be fully tested. It is possible it could last much longer.

The main issue with spray foam is that it will eventually separate from the area that it has been sprayed onto. The foam itself is often intact, but the adhesion has gone.

Any issues with spray foam insulation usually come down to incorrect application of the product. For example, areas that have been missed, or not sprayed thick enough will start to detach sooner than thicker areas.

Additionally, incorrect mixes of chemicals can cause the foam to pull away from the walls or rafters, and eventually fall out. A professional installation is essential to avoid this issue.

This can cause problems if you have chosen spray foam due to its ability to improve the structural integrity of your roof structure. Once again – ensure you are using a professional contractor.

The best thing about spray foam insulation is the fact that it will not be affected by the issues that can affect the life of other insulation types. Even if it becomes wet, it will not degrade, and the nature of the application means that leaks are very rare indeed, as all of the structure is covered.

It is also resistant to mould , and is unlikely to become damp as the application prevents moisture from building up. It is also not an attractive product for rodents, and will therefore be left alone – if they are able to gain access to the loft at all.

How Long Does Attic Insulation Last? Final Conclusion

Overall, you can expect all types of insulation to last for decades – certainly for as long as you live in your home. However, you should keep a close watch on it, and be prepared to replace it if it appears to have been affected by any of the issues mentioned above.

Changes in recommendations should also be considered, and insulation topped up as required.

There are very few products in our home that will last up to 100 years, and continue to make us money for that entire time. Insulation is certainly a special product, and one we should all consider.

Seeking out an insulation solution that stands the test of time? Say hello to spray foam. Learn more about how this marvellous multi-purpose product can help you cut your costings today, by calling 0800 1700 636, or by simply clicking the button below!