Pests Under Garden Room: Rats, Mice, Foxes and How to Stop Them

Rats are the highest-priority pest species in garden room sub-bases. They burrow extensively, gnaw structural components, and in established colonies can access the building interior through service penetrations. The fire risk from cable gnawing in a garden room with power infrastructure is significant. Rats also produce large volumes of urine that contaminate the sub-base with a persistent odour.

Mice are the hardest species to exclude. Their small body size allows access through gaps that standard perimeter skirting will not address. Mice target floor insulation specifically, pulling material down into the sub-base to build nests. The thermal performance impact of mouse insulation damage in a garden office used year-round is a practical operational problem.

Grey squirrels use garden room sub-bases for food caching and nesting. Their gnawing force is considerably greater than rats or mice, and the organic material they cache in the sub-base accelerates timber decay. Foxes, where they access garden room sub-bases, use them as breeding dens and create severe odour and contamination issues that require the floor structure to be partially opened for remediation.

Individual pest species require different management approaches — rat bait stations are different from mouse traps, which are different from fox deterrents. But the structural access point that all of these species exploit is the same: the open sub-base of the garden room, accessible from ground level at the perimeter and wherever the pile pattern creates gaps.

A single physical barrier — a welded wire mesh at ground level across the full footprint — addresses all species simultaneously. By closing the structural access point, it eliminates the entry route for all species without requiring species-specific management responses for each individual problem that emerges.

The sub-base barrier must be installed before the garden room floor frame is assembled. At that stage, the full footprint is accessible and the barrier can be deployed, lapped, and secured with complete coverage. Once the building is in place, access to the full footprint is no longer possible. Retrofit coverage is always partial.

The cost of installing a sub-base barrier at construction is a fraction of the cost of remediating even one rodent infestation in an installed garden room. Insulation replacement, pest control visits, floor structure remediation, and cable repair can collectively run to thousands of pounds — compared to the cost of a roll of correctly specified barrier mesh installed in 30 minutes.