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Spray Foam Insulation

Hemp Insulation vs Fiberglass: How Do They Compare?

Hemp Insulation vs fiberglass

When you decide to install insulation in your home, you must research all products, source the best one, and shop around for a legitimate company.

If you’re hoping for more cash in your pocket, insulation’s the one investment that offers guaranteed returns. Not only does it help you save money on your energy bills, it also increases the value of your home immeasurably.

If you’re deciding between either fiberglass or hemp insulation for your home, we’re here to provide some assistance.

So without further ado, let’s take a look at the advantages and disadvantages of both choices, and consider whether the modern alternatives on the market might offer a more effective solution…


Fiberglass insulation can be found in two different types of insulation. The first one is blanket, which is basically batts and rolls of insulation, and loose fill insulation.

Sometimes, you can find fiberglass as rigid boards and duct insulation. Fiberglass is an insulation product composed of extremely fine glass fibers.

Nowadays, manufacturers produce medium and high density fiberglass insulation. These prove preferable to batts, due to the higher R-values they possess overall.

High-density fiberglass insulation can get to a maximum value of R-15. Low-density fiberglass insulation gives R-11 value, while medium-density offers value of R-13.

All of these calculations are for batts of 2 by 4 inches. If you get 2 by 6 inches batts, you can increase the R-value considerably. That being said, let’s take a look at the pros and cons of fiberglass insulation.


  • Inexpensive and effective
  • Does not shrink
  • Fiberglass batts come with a plastic covering that acts as an effective vapour barrier
  • Fiberglass is made of recycled glass, making it eco-friendly, and improving your carbon footprint in the process
  • Insects to not eat fiberglass


  • You always have to use plastic-sealed batts, otherwise there is no vapour barrier
  • Fiberglass will not help you seal walls and ceiling spaces tightly
  • Fiberglass is not the healthiest product to have around. Some studies have shown that inhaled slivers of fiberglass can cause lung disease
  • Fiberglass uses formaldehyde as a binder, which can leak out in the air
  • Over time, the R-value of your fiberglass insulation decreases. This is because fiberglass settles and sags over time

Hemp Insulation vs fiberglass

Since it is breathable, hemp also regulates condensation, by allowing moisture to travel. Hemp insulation is best for wood framed structures, as it prevents moisture building up inside the timber

Hemp Insulation

Another insulation material you can use is hemp insulation, a low-carbon and durable alternative. Since Ancient times, hemp has been used for ropes, clothing, sails, and much more.

Hemp insulation is made out of hemp fibers, resulting in a resilient and breathable material. Hemp insulation helps you regulate thermal performance.

Help is great insulator because it has low conductivity levels, and high thermal mass. Once you install hemp insulation, your home will be cool in the Summer, and warm in the Winter. Hemp insulation also helps minimise the intrusion of outside noise.

Since it is breathable, hemp also regulates condensation, by allowing moisture to travel. Hemp insulation is best for wood framed structures, as it prevents moisture building up inside the timber. Here are the pros and cons:


  • Renewable material
  • Some products contain recycled materials
  • Reusable in some conditions
  • Hygroscopic (provides a degree of humidity control)
  • Pesticide use is very rare
  • Can be used in energy recovery


  • Contains non-renewable material, polyester binder
  • Production of hemp insulation contributes to global warming
  • Thermal conductivity can be increased by compaction and moisture
  • Relatively untested
  • Contains an ammonium phosphate

Hemp Insulation vs fiberglass


Why Choose Spray Foam Instead?

If your dilemma is between hemp insulation vs fiberglass, then you should think outside the box; there are many newer materials that you may not have even considered!

There are other types of insulation that combine the best parts of hemp and fiberglass. One such material is spray foam, which is much more effective than fiberglass.

In recent years, spray foam insulation has slowly risen up in the ranks. Due to the fact that fiberglass is the most common insulation material, we compare how spray foam competes with fiberglass. Take a look at the results below: 

  • While fiberglass allows some leakage, there is no leakage with spray foam insulation
  • Spray foam insulation is much more efficient than fiberglass, reducing your energy bills by 50%
  • In extreme cold conditions, fiberglass loses heat quickly, while spray foam allows no heat loss
  • The R-value of fiberglass is 2.2 per inch, and loses its R-value over time. Spray foam insulation has an R-value of 3.5 for open cell
  • The lifespan of spray foam insulation is 50+ years, while fiberglass can last for 10 to 20 years at max
  • Spray foam insulation provides much better sound barrier efficiency
  • When used to walls and roofs, spray foam adds up to 250% racking strength
  • Spray foam insulation stops air and moisture infiltration, keeps dust and pollen out, and reduces wear and tear on your HVAC equipment

In fact, the only advantage fiberglass has over spray foam is cost, but although fiberglass is initially cheaper, spray foam is far more cost-effective long-term, as it performs for the life of the building. Simply call 0800 1700 636, or click the button below to get the ball rolling today!