How to Insulate Your Shed or Garden Room for Winter

Published: September 8, 2025

A shed or garden room doesn’t have to sit unused in the colder months. With the right insulation, you can keep it warm, dry, and functional—whether it’s a home office, gym, or simply tool storage. Here’s how to do it using materials from Wood Green Timber.

What You’ll Need (From WGT)

• PIR Insulation Boards (or RWA45 / Loft Roll)

• OSB or Plywood Sheets

• Treated Timber Battens

• Damp-Proof Membrane or Vapour Barrier

• Sealant & Fixings

Tools You’ll Need

• Saw or Knife (to cut insulation)

• Staple Gun

• Drill & Screws

• Sealant Gun

• Tape Measure

Step 1: Clear and Inspect

Empty your shed or garden room and check for leaks. Seal gaps before starting.

Step 2: Install Damp-Proof Layer

Fit a vapour barrier or damp-proof membrane inside the walls to prevent moisture issues.

Step 3: Add Insulation

Cut PIR boards to fit snugly between battens. Alternatively, use Rockwool or loft roll for a cost-effective option.

Step 4: Line with OSB or Ply

Fix OSB or ply boards over the insulation for strength and a neat finish.

Step 5: Roof & Floor

Insulating the roof and floor makes the biggest difference—don’t skip this step.

Step 6: Seal Gaps

Use sealant or expanding foam around windows, doors, and edges to stop draughts.

Top Tip from WGT

If you’re planning to plasterboard and decorate, save money by using ply on the hidden walls and premium finishes only where it matters.

Featured Products at WGT

• 50mm PIR Insulation Boards

• 18mm OSB3 Structural Board

• 12mm Hardwood Plywood

• 38x63mm CLS Battens

• Damp-Proof Membranes

With just a weekend’s work, you can turn your shed or garden room into a warm, functional space for the winter. Visit us at Wood Green Timber or order online for quick local delivery.

? For more inspiration, see our Top 5 Timber Projects to Prepare Your Home for Autumn.