How to Stop Rodents Getting Under Your Garden Room

Garden rooms raised on screw piles, adjustable feet, or bearer systems create an open sub-base void. This void is typically 150-400mm high and extends across the full footprint of the building.

Without a physical barrier, this space is fully accessible to rats, mice, and other wildlife from all directions — including from below via burrowing. Perimeter skirting alone does not solve the problem. This issue affects garden rooms, raised decking, and garden sheds alike — see our full guide to preventing rodent access beneath raised structures for the complete picture.

The most effective way to stop rodents under a garden room is to install a sub-base barrier that covers the full footprint of the structure at ground level.

BaseShield™ SubBase Defence is designed specifically for this purpose. Each roll covers 25m² (1m × 25m), rolls out flat across the prepared ground, and overlaps to create a continuous barrier.

Install the barrier before the garden room is placed, or during the foundation stage of the build. This is the easiest and most reliable time to do it.

Once the sub-base barrier is in place, secure the edges to the base frame or foundation structure using appropriate fixings. Ensure there are no gaps larger than 7mm around screw piles, service entries, or drainage points.

If skirting or cladding is being fitted around the base, the sub-base barrier should extend to or beyond the outer edge of the skirting line.

While the barrier itself requires no maintenance, good practice around the garden room helps reinforce the protection. Avoid storing food waste, bird seed, or pet food near the structure. Keep vegetation trimmed back from the base. Ensure any drainage or service penetrations through the barrier are properly sealed.

Installing a sub-base barrier during the build is dramatically easier, cheaper, and more effective than retrofitting one later. Once the garden room is in place, accessing the sub-base typically requires removing skirting, lifting sections, or working in confined spaces.

For detailed installation instructions, see our installation guide.