Should You Remove Your Old Loft Insulation?

Old Insulation

When loft insulation is in its prime, you should enjoy the benefits in terms of a much more comfortable home and lower energy bills. However, your home insulation can start showing the effects of ageing, as it either gets damaged or worn out. 

When this is the case, the thermal performance decreases and energy bills take a hit. Is this the time when you should remove your old loft insulation then?    

Here we’ll tell you everything you need to know about loft insulation and when you need to remove existing insulation.  

Assessing Your Existing Insulation 

Proper insulation can significantly affect energy bills and climate control devices. But, before deciding to replace the old insulation entirely, it’s best to assess its condition.

Here are some key factors to consider.  


How old is your insulation? Generally speaking, some older houses (the ones built before 1990) lack insulation altogether while others have poor or degraded insulation that offers very little insulation resistance (low R-values). 

Newer installations might be in better condition or in need of surface-level maintenance. You’d be fortunate if your loft is in that category. 

A less fortunate scenario comes with new loft insulation that’s gone through some rough events. Vermin, water damage, or heat damage are all possible causes of untimely degradation of insulation materials.  


The type of insulation material is a defining factor in whether or not you need to remove and replace your old loft insulation. Some are known to be durable, while others degrade quicker and need topping up or replacing entirely.

Here’s a breakdown of common insulation materials and their expected performance. 

Material Why We Choose It The Snag
Mineral WoolDurableFire resistant Prone to moisture damageSettles after a while
Glass FibreDurableLow fire resistance
Rock WoolEfficient Fire resistant New MaterialExpensive 
Loose FillGood for awkward inaccessible spacesSettles unevenly 
Reflective FoilEffective for radiant heatNeeds additional insulation


Three physical features reveal the condition of your loft’s insulation: 

  1. Visible damage: Tears, rips, or matting are strong indicators that the insulation isn’t reliable. The degree of damage should dictate whether it needs topping up or total replacement. 
  2. Moisture damage: A musty smell is the first tell. Moisture is often a fine breeding ground for mould and fungal growth, and they both give off an unpleasant odour. 

You can also check for water stains. This is a different indicator of water leakage and in that case, you should trace the source and fix it before moving on to changing the insulation. More often than not, you’d need to replace the material entirely.

  1. Settling: When the insulation settles unevenly, it often leaves gaps. Thermal bridges usually form whenever the insulation shows such irregularities. This naturally reduces its efficiency and effectiveness significantly.   

Finally, look for insects and rodents. If the insulation isn’t in good condition, there’s a reasonable probability that bugs and uninvited little visitors would form buzzing communities inside it.  


The most tangible factor you’d notice is the figure on your energy bill. If you’re getting overly large bills that steadily increase over time, then you should inspect the insulation. It could possibly be the culprit. 

Next, go from room to room. If the temperature varies for no particular reason, or there’s an unexplainable draft and cold spots, that’s another indicator of faulty insulation. 

With such temperature fluctuation, you’d also see condensation on the windows. Poorly performing insulation causes humidity issues, which explains the fogging on your glass. 

These symptoms are inconclusive though. To decide on removing your old insulation, you’d need a more definitive assessment. The best way to get that is by using the services of a professional installation contractor. 

A specialist can run a home energy audit, and give you a full report. They have the required tools and expertise to measure the R-value of the insulation and assess its overall condition.   

Reasons to Remove Old Insulation 

Insulation material often looks tired, shapeless, and worn out after just a few years. It’s sometimes tempting to rip it all out and start fresh. But let’s not do that right away! 

Insulation material needs total replacement only if no part of it can be salvaged and topped up. In that case, a major overhaul would be in good order. Here are some deciding factors that justify a complete insulation replacement. 

Damage and Contamination 

Physical signs of damage are easy to spot. If the insulation looks shabby and beyond rescuing, just throw it away. It reduces the R-value significantly, which puts the energy bills on steroids. 

Water damage is among the worst issues for insulating materials. A byproduct of soggy insulation is the growth of black mould and various other nasty organisms, which are not only  unsightly and foul-smelling, but can lead to ill health and trigger allergies. Replacing the insulation then becomes highly recommended. 

It’s worth noting here that leakage from the roof is frequently behind this issue. It’s best to perform some checks and ensure the soundness of the roofing before replacing the insulation.    

A similar situation comes with rodents and insect infestations. Again, you need to treat the cause first. Then, you can start fresh with newly installed insulation.  

Safety Concerns

The old insulation material (before 1980) should also pass a fire safety check. Older insulation materials might not be fully compliant with fire safety standards, so a specialist needs to make that assessment. 

It’s also important to look for outdated materials like asbestos. It could constitute a health hazard. Any insulation containing this material needs to be replaced. Professionals are well equipped to handle it and dispose of the old material according to specific protocols of safety. 

Renovation Projects

Many people change their lofts into livable spaces if they are spacious enough. Even smaller spaces can be used as nice storage areas with dry shelves. In that case, the insulation should be removed and replaced with drastically different materials. 

Compliance with housing regulations necessitates that. Also, it would be necessary for proper thermal performance. 

Common renovation projects include removing the old loft insulation to change the electrical wiring of the house. Sometimes that’s the only way to access the areas where the wiring needs to run. Usually, contractors replace the insulation material entirely when they’re done. 

The same happens if you make changes in your house’s ventilation system. Again, the loft is stripped to the bone, and then reassembled, when all is good and finished.     

Alternatives to Removal 

Before ripping the old insulation, and going knee-deep in a potentially costly renovation project, there are two alternatives you might want to consider. These options would be easier on the wallet, and they’re certainly less messy.

Topping Up 

This is an ideal choice if your current insulation is in good working condition, but lacks the necessary thickness for full compliance with the regulations. It’s also appropriate if you only need to supplement the insulation to overcome its unevenness. 

You can top up the existing insulation either with another layer of the existing material or with a new type of insulation. If you opt for the second, just make sure that it’s compatible with the base layer.   

The main benefits of this method are that it’s cost-effective and minimally disruptive. It might not be suitable for all types of insulation though, and it can be particularly difficult in limited spaces. 

Partial Removal and Replacement 

Targeting a specific spot is ideal for situations where there’s partial damage in the insulation. Local areas containing insects or rodents can easily be extracted and replaced. The same applies to torn or damp insulation, as long as it hasn’t spread around too much. 

This saves on materials and it can be done fairly quickly. It’s important to make sure that the damages are in fact restricted to that specific spot. If needed, you might have to do some cleaning and sealing before installing the new insulation. 

Final Verdict: Should You Remove Your Old Loft Insulation? 

If you’re reading this, it’s probably fair to assume that you’re not too satisfied with the current insulation in your loft. This leaves us with three courses of action: total replacement, partial replacement, or topping up. So which one is the right choice?  

We recommend consulting a qualified insulation contractor to do the necessary assessment. A specialist can perform a thorough inspection and give you the most cost-effective and energy-efficient solution.  

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