Intumescent Cutters
Intumescent cutters are specialist router bits designed to cut precision grooves for fire-rated door seals and intumescent strips. Used in certified fire door installations, these bits create a consistent channel to maintain legal compliance and site safety.
What Are Intumescent Router Bits Used For?
These cutters are engineered for one purpose — to route a clean, uniform slot in the edge of a fire door or frame, ready to accept intumescent or smoke seals:
- Fire Door Installations – Cut compliant slots for 10mm or 15mm fire strip inserts.
- Intumescent Strip Routing – Create recesses for heat-expanding seals in timber door edges.
- Smoke Seal Channels – Used for combination seals to prevent smoke ingress.
- Uniform Width & Depth – Ensures flush fitting with no gaps or over-cutting.
Used By:
- Fire door installers
- Joiners manufacturing rated timber doorsets
- Carpenters fitting fire-compliant doors in flats, hotels, and schools
- Site contractors handling retrofits or passive fire protection upgrades
What to Look for in an Intumescent Cutter
Precision and compliance are the priority — here's what to consider:
1. Cutter Width
Choose 10mm, 15mm or 20mm depending on strip size. Most fire seals use 10mm or 15mm depth.
2. Tip Geometry
Square or radiused tips allow for different strip profiles — check your seal manufacturer’s spec.
3. Cutter Material
TCT tips are best — long-lasting and reliable when cutting fire door cores, hardwoods or veneered edges.
Intumescent Cutter FAQs
What is an intumescent cutter?
It’s a router bit used to cut grooves in fire-rated doors or frames so that intumescent fire seals can be installed correctly.
Are these required for fire door certification?
Yes — most FD30 and FD60 installations require intumescent strips to meet fire protection regulations. These grooves must be consistent in width and depth.
Can I use these on veneered or solid core doors?
Yes — TCT versions are suitable for solid timber, veneer, MDF or core-constructed fire doors.
Do I need a jig or guide?
Yes — a router jig or fence is strongly recommended for consistent slot depth and safety during repeated cuts.
What size bit do I need?
Most installers use a 10mm or 15mm bit depending on the strip. Check the seal spec before choosing a cutter.
