How can I insulate my warehouse/workshop building?

Common questions we encounter with larger warehouses are questions around insulating and controlling the temperature. This can be for a number of reasons:

  • Productivity: If there are going to be many people working inside a building it can make good sense for productivity and staff retention to insulate and heat. Anecdotally, we have heard about certain employers being known as a great place to work because the workshop was warm in winter.

  • Manufacturing: In some processes, there is a requirement for a building to stay at a relatively consistent temperature such as honey extraction.

Ways to insulate a building

Over the years we have seen several ways to insulate a building - and each has its pros and cons depending on your budget and requirements.

Key Methods

  • Insulate the building cavity with pink batts and line with plywood, MDF, or GIB.
  • Roof blanket laid under the roof as an underlay.
  • PIR/EPS panel - often known as a freezer panel or cool store panel.
  • Insulation laid between 2 layers of roof cladding (roof logic).

Insulating with pink batts

This method is much the same way that a house is insulated. The exterior of the building is clad and inside the insulation is put between the cladding and an internal lining - such as plywood or GIB.

insulating with pink batts

This is usually used in offices and smaller workshop/assembly areas with a low stud height.

The pros and cons of insulating with pink batts

Pros

  • Provided the building has wall wrap and a cavity, it can be retrofitted at a later date.
  • It is a good solution where the inside needs to be lined anyway rather than left as bare framing. For example, in offices inside a main structure or a lined workshop area.
  • You can get quite a high R-value depending on the size of the wall framing.

Cons

  • It can require a lot of labour hours to install all the insulation and lining materials - particularly in a high area like a warehouse where builders would have to work at the height of scaffolding or elevated work platforms.
  • Depending on the wall framing type (steel or timber) thermal breaks may also be required which is extra labour and cost.
  • If you don't require the inside of the building to be lined, it can be quite a lot of extra material and labour cost.

Underlay Blanket laid between the cladding and framing (purlins/girts)

This method is where the building paper is replaced with a thicker ‘blanket’ type material to give some additional R-value, see here.

thermo reflective insulation

The pros and cons of an underlay blanket laid between the cladding and framing

Pros

  • A building does not always need to be lined, so there is a cost-saving compared to methods that require lining.
  • It’s fast to install (as it replaces the building paper) so there are labour savings onsite.
  • It’s a 3-in-1 insulation, vapour barrier, and radiant barrier.

Cons

  • The R-value is typically quite low so it is not always suitable for inhabited areas or offices.
  • As it is not lined, the underlay is susceptible to damage over time - either through deterioration or scrapes and cuts from day-to-day operations. This will reduce the effectiveness over time.
  • The product is about $20-30 per m² which is 4 to 6 times the cost of building paper, so the price is a jump up from standard wraps.

PIR/EPS panel - often known as Freezer panel or cool store panel

This is a well-known product used for cool stores hence it is often called ‘freezer panel’. However, it can be used to also keep buildings warm! These are structurally insulated panels and are traditionally made up of 2 sheets of colour steel with EPS (polystyrene) or PIR bonded between.

The colour steel can be flat on both sides or have a side ribbed or corrugated, see here. The cost is often less than lining and using batts, especially when larger R-values are required.

PIR/EPS panelCool store panel insulation

The pros and cons of a PIR/EPS panel

Pros

  • The exterior cladding, insulation, and internal lining are all in one.
  • The panel is quite strong so often the building requires fewer roof purlins and wall girts which can provide savings.
  • It has excellent thermal properties and R-values with a variety of panel thickness options.
  • The internal surface is flat and made of colour steel which is easy to keep clean and ideal for areas that require easy cleaning, e.g. food processing areas.

Cons

  • If you use panels with a EPS (polystyrene core), it is very bad in a fire and consequently very difficult to insure. However, most manufactures now use PIR or a different core than polystyrene which is fire rated.
  • Some suppliers can only supply sheets up to 12m long which may require joining onsite. This can create more onsite work and an increased risk of leaks.
  • In the past, there have been plenty of stories in the industry of problems with the panels leaking over time - particularly when flat panels were used and there were joins in the roof. There are now a lot more products on the market that mitigate these yesteryear issues but it is wise to ask your designer and/or builder if they are considering these factors.
  • As the panel is metal on both sides it can make the building very noisy as the whole interior is metal and very good and transmitting sound.
  • Large panels can take a while to install and require lifting equipment to be onsite for the duration of the install.

Insulation laid between 2 layers of roofing (Roof Logic system)

This system builds up roof insulation by first laying a ‘liner deck’ of roofing down on the purlins, and then installing an insulation layer on top of this, with a final roof layer on top - this article explains the process. This is really another way of getting an insulation value similar to PIR panels.

The pros and cons of insulation laid between 2 layers of roofing

Pros

  • Acoustic board layers can be added to absorb noise.
  • It’s easy to achieve high levels of insulation.
  • The roof substrate can be quickly installed by hand on the roof. This means the building can be weather tight quickly and allow works to continue inside while the insulation layers are added and the roof installed. This can help reduce the overall project timeline and allow different trades to overlap their works.
  • It’s easy to get weathertight and has less risk of leaks than some freezer panel systems.

Cons

  • It can be more labour overall than installing PIR, but if it is a very large roof the extra lifting equipment required for PIR panels can negate this extra labour.
  • It is a premium option so typically comes at a higher price point.
  • At this stage it doesn't appear that there is a system suitable for walls as well - so if you require walls to be insulated they would need to use one of the other methods mentioned above.

So there you have it, the four main ways to insulate a warehouse, workshop, or shed. As explained, it does come down to your requirements and priorities. If you would like to discuss this further, please feel free to reach out to one of our friendly expert team members.

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