Spray Foam Insulation vs Traditional – Updated 2020 Guide

Spray foam insulation installed vs traditional

Today we discuss on Spray foam insulation vs traditional. Here we go again, another debate on what the most suitable product for your home is. With all these mixed reviews on the internet, it’s easy to be confused about whether spray foam insulation is better than traditional insulation.
Don’t worry! – We have noticed all the confusion and have decided to make your life easier. So, sit back, scroll and read about the differences, how they are installed, the pros, the cons, and the costs.

What is Spray Foam Insulation?

Spray foam is a revolutionary insulation option that has taken the UK by storm within the past several years. Spray Foam Insulation has become increasingly popular due to its unique characteristics. Spray foam insulation is an insulation type that seals lofts, walls, floors and can be applied to fill the voids in ceilings and thus acts as an air barrier material.

Once spray foam is applied It never sags, or cracks, unlike any other traditional insulation methods. Open cell spray foam insulation can be expanded up to 100 times its original size and fills cracks, gaps and never loses its shape compared to other traditional insulation types.

Spray foam insulation has been known for increasing the comfort and energy efficiency of your home. Hence why existing homeowners are moving to Spray foam insulation as it is a far more superior product and also lowers their energy bills and save money. This also gives a clear picture that Spray foam insulation is widely accepted compared to the Traditional insulation methods.

The Spray Foam insulation is also refined completely to ensure that your home meets the building codes for the day and performs for the entire life.

Here is a list of the traditional insulation types and more information on them for you so you can decide how they compare up against the superior spray foam insulation:

  • Fiberglass Insulation
  • Cellulose Insulation
  • Celotex Insulation
  • Rockwool Insulation


spray foam insulation vs traditional

What is Fibreglass insulation?
So, starting off with one of the most common traditional insulation types,Fibreglass is a popular traditional insulation option on the market. Developed in the 1930s, the candy floss-like insulation is the go-to insulation method to date. This is no surprise as fibreglass is one of the cheapest insulation methods, whilst providing similar qualities as to the pricier alternatives. Fiberglass comes in two options, blankets and loose fill, this insulation has been populating the homes around the UK for centuries.

Pros of Fiberglass Insulation

  • Fibreglass is an inexpensive insulation choice
  • Fibreglass is does not shrink
  • This is an in flammable insulation type
  • Is environmentally friendly, using recycled glass
  • It has a U-value of 0.3

Cons of Fiberglass Insulation:
We must remember fibreglass has been around from the 1930s and is still such a popular choice. There must be a reason for this. Simple! It is such a remarkable product. Well you would think. However, every insulation has its downfalls. Some greater than others.

  • Blankets of fibreglass struggle to cover all gaps and crannies
  • Fibreglass contain harmful glass particles that can cause respiratory irritation

What is Cellulose insulation?

Cellulose insulation is also another traditional insulation. It consists of cellulose cells that have natural insulating power. It is made of shredded paper plus a fire-retardant chemical known as a borate. The paper is broken down into cellular fibres which provides insulation.This insulation is installed into your loft using an insulation blower and the fibreglass fibres flow through a long hose and are blown / sprayed into your loft space. The blown cellulose is prone to create dust that is blown into the holes or inadequate seals around fixtures. This is a health hazard.

Pros of Cellulose Insulation:

  • Cellulose insulation is environmentally friendly
  • This type of insulation provides more performance value than Fibreglass
  • It is Fire and mould Retardant

Cons of Cellulose Insulation:

  • Cellulose insulation can be very messy upon application
  • This insulation method needs a lot of space for installation
  • There are moisture issues in Cellulose insulation

What is Celotex Insulation?

Celotex is a hard insulation product which can be made by gluing the laminated aluminium foil facings together. Celotex insulation boards have an improved thermal performance other than the other traditional insulation products and this also makes it a desirable product.
This  insulation products are very light weight and this also makes it easy to move and apply.

Pros of Celotex Insulation :

  • Celotex Insulation is good for thermal performance
  • This insulation type is the preferred choice of PIR insulation
  • These products don’t absorb water
  • Celotex products have Low emissivity properties
  • The Celotex products doesn’t sag,absorb moisture or get permeated by air

Cons of Celotex Insulation:

  • Doesn’t fill all the gaps
  • Isn’t airtight
  • Cold air infiltration
  • Can fall out
  • Not flexible

What is Rockwool Insulation?
Rockwool insulation which is also known as the “Mineral wool” is one of the traditional insulation types. It comes in easy to install batts similar to Fibreglass but instead of being composed of fluffy fibres of glass, rockwool is composed of ….. of-course Rocks! The rocks are heated to 3000 degrees in a furnace until it melts into liquid, and the magma is exposed to high pressure jet of air and then spun into long fibre strands at high speed.

Pros of rockwool insulation:

  • Rockwool insulation is Fire resistant
  • Mineral wool insulation is Water repellent
  • This insulation have excellent thermal insulating properties
  • The Rockwool insulation is breathable

Cons of rockwool insulation:

  • Rockwool can be irritating to the skin and the lungs if breathed in.
  • Rockwool is a Health hazard as it is made of rocks and dust
  • Mineral wool insulation or Rockwool will start to sink, compress and sag as it ages
  • This type of insulation will not dry easily if it becomes damp or wet.

How is Spray Foam Insulation installed compared to Traditional types?

Spray foam insulation installed vs traditional

Spray Foam Insulation Installation and cost Explained:

Spray foam insulation is installed by a unique ‘spraying’ technique and can only be done by professionals. Since Spray foam insulation requires a lot of professional skills , you have to get it installed by an accredited insulation contractors.  Spray Foam Insulation compared to Traditional is much easier to apply and much more hassle free for the installers.

The installers on our network are experienced and trained in spray foam insulation and work safety, always wearing protective equipment whilst installing the material. All contractors apply the foam directly from their purpose-built vans and equipped to create complete air seals in the property.


Spray foam insulation compared to Traditional methods are more costly also spray foam insulation is not the cheaper form of insulation, but it is much superior form of insulation available in the market today.

To calculate how much Spray Foam Insulation Cost per square metre depends on 4 main factors:

  • The size of the project
  •  Thickness required
  • The labour needed
  • Type of spray foam insulation (Open Cell or Closed Cell)
traditional fiberglass vs Spray Foam Insulation

Fibreglass insulation installation and cost explained:

As you may know fibreglass comes in two forms; blankets and loose fill. Why? This is as depending where the insulation is going (between timbers, underfloor, loft floor) the installers will choose the most suitable one. Loose fill is applied to the floor of a loft, so this would be installed using a hose. Picture a firefighter carrying a hose and that is exactly what it would look like. Installers will spray enter your home with a huge hose and spray the confetti-like fibreglass across the loft floor. Fibreglass blanket is installed different. The candy floss-like insulation is rolled out and cut to size of your timbers and stuffed in.


Fiberglass batts are the most inexpensive ways to insulate your home. Large and rolled batts of fibreglass are fitted to fill the large voids and stop air from going through the exterior walls.
The average cost of Fiberglass per square foot is between 0.50GBP – 0.93GBP.

Spray foam insulation vs traditional cellulose

Cellulose Insulation installation and cost explained:

Both Spray Foam Insulation and Cellulose are sprayed in, but since the material is different, the outcome will be different when spray foam is applied, it starts as a liquid but expands into a foam after some seconds. If you are looking for an environmentally friendly insulation for your house, then cellulose insulation will be a great option for you.

Cellulose insulation is made from old newspapers and other waste papers.The  Cellulose insulation can also be applied to lofts, walls, and underfloor to provide a thick layer of insulation. One of the advantages of using Cellulose insulation is that it can be installed over the existing insulation which helps in saving your money and time.
Dense pack Cellulose and Wet spray cellulose are the two types of Cellulose insulation commonly used.
Dense pack Cellulose is used to insulate the wall cavities and other enclosed spaces whereas Wet spray insulation is used to insulate the open areas in new construction. The Dense pack cellulose completely fills the space with maximum amount of insulation.


The average cost of cellulose Insulation starts from 0.65GBP per square foot .

Spray foam insulation vs traditional celotex

Celotex Insulation installation and cost explained:

Celotex insulation helps in achieving the designed u values with the possible thickness.For insulating floors,walls and beams we can use Celotex which provides high performance.
This insulation method is more versatile ,high performance and provides a great solution for all internal wall insulations.If you are planning to insulate masonry wall with no wall cavities, this insulation type will be the right fit for you.This type of insulation will reduce the risk of thermal bridges
Celotex insulation is a high performance and rigid PIR board with low thermal conductivity and it makes them one of the best performing insulation materials in the market.


  • The price of Celotex insulation depends upon the size and the type of Celotex material
  • Conservatively 20% is waste
  • Potential of having to hire a skip
  • TRADESMAN Labour Price which varies
  • For example the average cost of Celotex 100mm insulation board with 2400mm x 1200mm is 33GBP
Spray foam insulation vs traditional rockwool

Rockwool Insulation Installation and cost explained:

Rockwool or Mineral wool insulation can be installed on wherever you install Fiberglass or any other type of insulation. This insulation type can be done on attics, crawl spaces, walls, floors or ceilings but it would be better if we use this insulation in the interior rooms in the house so that you can avoid noise disturbances. The Rockwool insulation is fire resistant and its ideal to use as a firestop between the floors of a house.
Mineral wool is firm and dense and its friction fits into the stud space, also Mineral wool have a shape. Mineral wool insulation always fits in the wall cavity without any gaps, spaces etc.

Insulation batts can be cut with a knife or handsaw to fit into the place. You can cut Mineral wool into any size depending upon your requirement. If it gets wet, water rolls off without entering and soaking the insulation fibres. The Mineral wool insulation fibres are so tightly compacted so that there will be no chance of shifting the position. Remember that Rockwool will come without any foil barrier or craft paper.

Rockwool insulation costs more than the Fibreglass, Fiberglass insulation R-15 costs around 0.39GBP per square inch whereas Rockwool insulation rated R-15 costs 0.48GBP per square foot.

How Can We Help You?

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No matter what kind of insulation or project you need doing, spray foam quotes compare makes it fast and simple to help you connect with the most suitable contractor.
We also know that price is important to you, after all, that’s why you’re comparing. But everyone has different needs, so we aim to help you find the right quote.