Practical Guide: Door Frame Timber and Fire Rating

When it comes to fire doors, the frame is just as important as the door leaf. The type of timber you choose for a frame directly affects how long it will resist fire and heat. Below we’ve outlined the common timbers used for fire door frames, along with their typical fire performance.

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Common Timbers for Fire Door Frames

Redwood (Softwood)

Suitable for NFR (non-fire rated) and FD30 applications.

Lower density than most hardwoods → burns faster, which limits use in higher ratings.

Beech

Typically suitable up to FD30

Close-grained but not as dense as ash or oak.

Ash

Suitable up to FD60.

Dense and strong, good charring properties.

Maple

Suitable up to FD60.

High density hardwood with steady burn rate.

Sapele

Suitable up to FD60.

Stable, dense tropical hardwood.

Oak

Suitable up to FD60.

Excellent durability and density, widely used.

Walnut

Suitable up to FD60.

Dense hardwood, decorative and strong.

MDF (Medium Density Fibreboard)

Can be used up to FD60 when tested and certified.

Engineered material with predictable density, often used for veneered or painted frames.

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Density and Burn Rate

Fire resistance is heavily influenced by timber density:

Softwoods (e.g. redwood): lighter, less dense, faster burn rate → typically limited to FD30.

Medium-density hardwoods (e.g. beech): slower burn rate but still limited without additional protection.

High-density hardwoods (e.g. ash, oak, sapele, maple, walnut): char more slowly, making them suitable for FD60.

Engineered boards (e.g. MDF): predictable density, can meet FD60 when used in the correct tested system.

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Important Reminders

Fire resistance does not come from the timber alone.

For higher ratings (FD60 and above), frames may also require:

Intumescent strips in the frame.

Intumescent pads behind hinges, latches, and closers.

Specific frame-to-wall fixing methods.

Always follow the manufacturer’s certification for the door, frame, and hardware combination.

⚠️ Disclaimer: This guide provides general information. Always refer to the specific test evidence or certification for your door-set.

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What’s Next

In a future Practical Guide, we’ll cover FD90 and FD120 door frame materials, which use even denser or specialist materials.

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✅ Illustration concept for this guide

One clean visual with:

A straight-on light oak flush fire door inside a white-painted frame.

Labels pointing to the frame timber type (example: “Redwood – FD30”, “Oak – FD60”).

A density scale bar (low → high) to reinforce how density links to rating.

Small note on the graphic: “Certification always required”.