How Rodents Get Into Buildings and Equipment: Why Small Gaps Matter

Pest Exclusion
Written By Brett Morrissey

Rodent ingress does not always start with an obvious opening.

Small gaps around doors, building interfaces, service routes, ventilation openings and equipment can provide rats and mice with a pathway into areas where they can cause damage, contamination and disruption.

For commercial, industrial and electrical installations, identifying and dealing with those access points can be an important part of protecting the asset.

Small gaps can create big problems

Rodents are capable of taking advantage of surprisingly small openings. The CDC notes that mice can pass through a hole around 6 mm wide, approximately the width of a pencil. It recommends checking areas around doors, vents, pipes and electrical, water, gas and sewer services when looking for potential entry points.

In practical terms, that means an installation can appear complete while still leaving opportunities for pest ingress.

Openings can occur around:

  • doors and building interfaces

  • pipes and conduits

  • ventilation openings

  • equipment cabinets and enclosures

  • service routes through walls and floors

  • unused or poorly sealed openings

  • gaps created when services are added or modified

Queensland Government guidance specifically recommends sealing openings where pipes pass through external walls as one way of limiting pest access.

What damage can rodents cause?

Rodents are more than just an inconvenience.

Brisbane City Council identifies machinery and electrical wiring among the items rats can damage through gnawing. Queensland Government guidance similarly notes that rats and mice may damage cables and pipes.

Depending on the location and type of installation, rodent activity can contribute to:

  • damaged electrical or communications cabling

  • damage to insulation and other materials

  • contamination from urine, faeces and nesting material

  • damage to stored goods or packaging

  • increased maintenance requirements

  • disruption to equipment and facilities

For businesses and asset owners, even a relatively small entry point can therefore become a much larger maintenance issue if it allows pests access to sensitive areas.

Pest exclusion and pest control are not the same thing

Traditional pest control often focuses on dealing with rodents after they have entered an area, using measures such as traps or baiting.

Pest exclusion focuses further upstream.

The aim is to reduce the opportunity for pests to enter in the first place by identifying and protecting potential access points.

Queensland legislation has long recognised this principle. Requirements relating to rats and mice include taking reasonable steps to prevent them entering certain structures, with sealing or covering holes and gaps specifically identified as an example of those measures.

Exclusion does not necessarily replace pest-management programs, but it can form an important part of a broader preventative approach.

Not every gap should be treated the same way

This is where the application matters.

A permanent opening in a building may require a very different solution from a cable entry into an electrical enclosure.

Some installations may need:

  • a permanent physical barrier

  • a flexible barrier around an irregular opening

  • a non-curing material that can be removed and reworked later

  • a fire-rated sealing system

  • a solution that allows additional cables or services to be installed in the future

The best solution depends on the environment, the size and shape of the opening, the services passing through it and any applicable fire, electrical or construction requirements.

Simply filling every opening with the same product is not always the best approach.

Think about future access too

One issue that can be overlooked when sealing service entries is what happens the next time the installation changes.

Electrical and communications installations are often modified throughout the life of a building or asset. Additional cables may need to be installed, existing services may be replaced, or access may be required for inspection and maintenance.

Where future access is likely, a removable or reworkable exclusion solution may be more practical than a permanent seal.

Considering this at the original installation stage can make later changes easier while still helping protect the opening in the meantime.

A practical approach to pest exclusion

At Rat Out, we are building a range of practical exclusion solutions for different types of openings and installations.

These include reusable non-curing sealing compounds, flexible physical barriers and specialised sealing products for applications where factors such as future access or fire-rated systems need to be considered.

The objective is not to force one product into every application.

It is to look at the opening, understand what needs to be protected and select an exclusion method that suits the job.

Got an awkward opening?

If you have a building, equipment enclosure or service entry that is difficult to protect, send Rat Out a photo of the application.

We can have a look at the opening and help identify some practical exclusion options that may suit.

Visit ratout.com.au or get in touch with Rat Out to discuss your application.

Brett Morrissey