How to Effectively Seal a Letterbox Draught
Brush Strip Seals
Brush strips are one of the most common methods used to reduce draughts. Typically installed inside the letterbox, they use bristles to create a physical barrier to airflow. However, due to mail passing through daily, the bristles can deform or break down, reducing their effectiveness. They may also look untidy over time.
- ✅ Affordable and widely available
- ✅ Easy to install with adhesive backing
- ❌ Can trap debris or mail
- ❌ Bristles wear down or collapse over time
- ❌ Often still leaks cold air
Spring-Loaded Internal Flaps
Spring-loaded flaps are designed to automatically close after use. Found in many standard letterboxes, they offer minimal visual obstruction but generally lack any sealing capability. They are prone to rattling and loosening with regular use, especially during strong winds or daily mail delivery.
- ✅ Self-closing action adds convenience
- ✅ Simple retrofit product
- ❌ No insulation — just a thin flap
- ❌ Can be noisy during wind or mail deliveries
- ❌ Flaps wear out over time
Foam or Rubber Seal Pads
These soft seals are quick and cost-effective, often sold in DIY packs for sealing gaps around letterboxes. While easy to apply, they suffer from issues with longevity, adhesion, and flexibility, especially in variable weather. They may peel or compress within months of installation.
- ✅ Cheap and widely available
- ✅ Quick DIY fix
- ❌ Doesn't last in outdoor conditions
- ❌ Limited sealing performance
- ❌ Often needs replacing every season
The Magflap Magnetic Draught Excluder
The Magflap offers a refined alternative that removes reliance on brushes, springs, or compressible foam. Its magnetic seal ensures consistent closure after every use, while the solid metal design adds aesthetic value. With no internal flap needed, it reduces moving parts and visual clutter.
- ✅ Magnetic seal fully closes off draughts
- ✅ No moving springs or brushes to fail
- ✅ Durable finish, long lifespan
- ✅ Looks clean and modern
- ❌ Higher initial cost than basic options