0333 5771139
Online Quote

Disadvantages of Most External Wall Insulation Types

disadvantages of most external wall insulation types

External wall insulation is an effective way to create comfortable living spaces and enhance the energy efficiency of your home. When choosing a solution, it’s important to understand that not all external wall insulation types are created equal.

For example, while insulation boards are popular across the UK, they don’t necessarily perform as well as more contemporary solutions. In this article, we’ll explore the disadvantages of external wall insulation types, as well as spotlight some cutting-edge alternatives.

How does traditional external wall insulation work?

Before we get started, let’s take a moment to unpack how traditional external wall insulation works. The technique typically uses insulative boards to enhance the thermal performance of a building. These boards come in a variety of materials, including fibre cement and polystyrene. A render is usually applied over the boards to protect the material and create an aesthetically pleasing finish. Rockwool, a type of mineral wool insulation, is also popular in the UK.

8 disadvantages of external wall insulation types

While solutions like external wall insulation boards and Rockwool can be effective, they come with several disadvantages, which we’ll explore in more detail below:

1. Impermeability

One of the main disadvantages of external wall insulation boards is impermeability. This can cause issues if your existing walls allow moisture to pass through. Without external insulation boards in place, moisture simply evaporate aways after passing through permeable walls.

However, impermeable external insulation boards can block this path and prevent moisture from escaping, an issue that can lead to dampness in the walls or insulation material. To overcome this issue, a vapour barrier may need to be installed, or additional ventilation may be necessary.

2. Size

Another of the disadvantages of external wall insulation is size. External insulation boards are usually bulky and can add around 50mm to the exterior of your walls. This can create problems when installed around windows, doors or roof eaves. Addressing these issues can require costly adjustments and increase the overall cost of your insulation project.

3. Cost

Costs can quickly climb when installing external wall insulation boards. Projects typically involve extensive preparation of the walls which means you’ll start to accrue costs before insulation is even installed. As mentioned above, adjustments can also inflate the costs.

4. Insulation issues

As well as compromising the kerb appeal of your home, external insulation boards can create ‘cold bridges’ if gaps are formed around windows, doors or roof eaves. These weak spots compromise the thermal envelope of your home and allow heat to escape. If not addressed, these insulation issues can make installing external boards less effective.

5.  Irritation to skin and respiratory system

Wall insulation solutions like Rockwool are made of ultra-fine fibres. While thermally efficient, they can cause skin and respiratory irritation. Rockwool can also release tiny dust particles into the air, which can aggravate respiratory conditions.

Fibre-based insulation is always covered by a render, but the brittle nature of the material means it’s prone to crumble or break during installation. This can create debris which lingers in your home. Damaged walls can also expose fibre-based insulation and exacerbate skin and respiratory issues.

6. Weight

Compared to other external insulation solutions, materials like Rockwool and fibre cement boards can be heavy. This weight can increase structural stress on your home and make installation more labour-intensive.

7. Limited insulation value

Rockwool insulation is most effective when installed in thick layers. In thinner applications, it may not perform as well as other materials. Over time, fibre-based insulation can also settle which reduces its insulating properties.

8. Environmental impact

Many traditional external wall insulation materials have energy-intensive manufacturing processes and involve the use of raw materials like basalt rock and slag. This can be a turnoff for environmentally conscious homeowners.

Cork render: an alternative to traditional solutions

How do you get around the disadvantages of external wall insulation types like fibre cement boards, polystyrene panels and Rockwool? Modern exterior wall coatings like SprayCork offer excellent insulation properties while overcoming the disadvantages of traditional materials.

Why choose a cork render for your home? Here’s a few reasons why SprayCork is gaining momentum across the UK:

Natural and sustainable

Cork is a natural resource harvested from the bark of cork oak trees. It’s also renewable as instead of being felled, trees are stripped and allowed to regrow. This makes cork an eco-friendly choice and a great option for homeowners looking for an alternative to traditional materials.

Excellent thermal insulation properties

Cork boasts unique thermal insulating properties and is an efficient way to protect your home from the elements while reducing energy bills.

Crack resistant

Unlike traditional render materials that can crack over time, cork is flexible and won't fracture. Even when applied over existing cracked renders, a cork render finish remains smooth and flawless.

Reduces heating bills

Exterior cork renders drastically improve the thermal performance of your home and can reduce energy bills by up to 15%. In the long term this can offset installation costs.

Resistant to mould and condensation

Unlike external wall boards, cork render is breathable and allows moisture to pass through your walls and evaporate. This eliminates mould and condensation issues, which can compromise the structural integrity of your home and lead to health issues.

High durability

SprayCork comes with a 25-year warranty against issues like fading and cracking. This means you can insulate your home with total peace of mind. In rare cases where repairs are needed, patching is easy and there’s no need to refinish the entire area.

Excellent sound insulation

Cork rendering doesn’t just trap heat indoors. It can absorb up to 38dB of noise and help create a peaceful indoor environment. Whether it’s traffic, leaf blowers or construction noise, cork rendering can be a great insulation solution for noise-prone areas.

Fire resistant

Cork is a breathable material which makes it resistant to fire, yet another reason to choose solutions like SprayCork.

Enjoy best-in-class insulation with SprayCork by Total Trades

From added bulk to moisture and condensation issues, the disadvantages of external wall insulation types can create serious issues. Instead of troubleshooting, upgrade to a gold-standard solution like an external cork render. Award-winning products like SprayCork not only promise excellent thermal properties but are durable, sustainable and cost-effective.

Ready to upgrade? Total Trades is an approved SprayCork applicator in Doncaster. Contact our team on 0333 577 1139 to arrange a quote or find out more about our external wall insulation services.

Share This Post
Need help with a project?
View More Posts


linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram