A mid rail is the horizontal reinforcement bar set across a security door, improving rigidity, supporting lock hardware and helping the door meet recognised performance standards. We recommend positioning it to suit your handle height, lock type and accessibility needs, and checking it against AS 5039.1 and AS 5039.2 before manufacturing begins.
TL;DR:
- At least one home entrance needs an 820 millimeter clear opening, so position the rail, handle, and lock without narrowing the usable passage.
- Measure handle and lock centers, thresholds, and steps on site before manufacturing; otherwise, the rail may interfere with a three point locking system or latch.
- Confirm the door meets AS 5039.1 and installation follows AS 5039.2; request compliance documents, installer credentials, and written product and installation warranty terms.
- For coastal or damp entrances, stainless steel resists corrosion; heavy three point locks may warrant a wider or thicker rail to limit flex.
Table of Contents
- What a mid rail does for strength and style
- Where mid rails sit and how to measure for one
- Choosing materials and infill for your mid rail
- Installation, compliance and who should fit it
- Keeping your mid rail and hardware in good condition
- Choosing the right mid rail: a quotation checklist
- Our approach to mid rail design and installation
- Get a measurement and quote for your security door
- FAQ
- Sources
What a mid rail does for strength and style
A mid rail is not just a design line across the door. It stiffens the frame, stops the mesh or infill from flexing under pressure, and gives the lock and handle a solid fixing point rather than a thin section of mesh. On a well-built door, the rail ties directly into the stiles so the whole leaf resists twisting when someone leans on the handle or tries to force it.
The security value of a mid rail comes from how it is engineered and fitted, not from its presence alone. Forced-entry resistance is a certification matter, tested and rated under AS 5039.1, so a rail only contributes to genuine security performance when the whole door assembly is compliant.
- Rail width and profile change the visual weight of the door, from a slim contemporary line to a bolder traditional look.
- Finish options (powder coat, anodised, brushed stainless) let the rail match or contrast with the frame.
- Correct installation under the matching standard is what turns a structural feature into a certified performance one.
Where mid rails sit and how to measure for one
Placement starts with the clear opening width of your doorway, the usable gap once the door is fully open. For at least one entrance to a home, livable housing guidance sets a minimum clear opening width of 820 millimetres, along with requirements for thresholds and an unobstructed external landing. A security door fitted over that entrance needs its mid rail, lock and handle positioned so the opening stays usable.
Mid rail placement should suit the handle height, existing door hardware and frame. Before a quotation or site visit, a few simple steps make the process faster:
- Measure the clear opening width of the doorway with the door fully open.
- Note the height of your existing handle and lock centres from the finished floor level.
- Check for a threshold, ramp or raised sill, since these can shift where the bottom rail or sweep needs to sit.
- Record any step-down or step-up at the entrance, as ramp and landing guidance sets minimum ramp widths and landing sizes that affect how the frame is fixed.
A rail positioned without checking these details can end up clashing with a three-point lock, a letterbox slot or an existing deadlatch, so it is worth confirming placement before manufacturing starts.
Choosing materials and infill for your mid rail
Aluminium, steel and stainless steel each bring something different to a mid rail. Aluminium is lightweight, resists corrosion well and suits a wide range of powder coat colours. Steel is another option for larger doors. Stainless steel is another option for coastal or high-moisture environments. Compare maintenance needs and costs when choosing a material.
The infill around the rail matters just as much as the rail itself:
- Woven mesh can balance visibility, airflow and insect control for everyday security doors.
- Clear-view mesh keeps sightlines open for a near-unobstructed view, useful on doors where you want minimal visual interruption.
- Perforated sheet suits a more private or industrial look, trading some visibility for a solid appearance.
- Decorative grilles add a traditional or heritage aesthetic, often paired with a wider mid rail for proportion.
Finish choice usually comes down to environment and upkeep: powder coat gives a broad colour range and a tough everyday finish, while anodising suits homes wanting a more natural metallic look with strong corrosion resistance.
Pro Tip: If your door carries a heavy three-point lock or sees regular use from kids or pets, ask for a wider or thicker mid rail profile, since it may help spread the load across the fixings and reduce flex.
Installation, compliance and who should fit it
Two standards govern a compliant security door. AS 5039.1 sets the performance requirements, covering how hinged, sliding, folding, removable and fixed security screens resist forced entry. AS 5039.2 sets out how those same door types must be installed, and a door that passes performance testing still needs to be fitted correctly to retain that rating.
This is why installer credentials matter. A door built to AS 5039.1 can lose its compliance if it is fitted by someone without the relevant licence or security agent registration, which can affect insurance claims and safety outcomes down the track. When reviewing a quote, check for:
- Written confirmation the door and screen meet AS 5039.1 performance requirements.
- A clear explanation of the installation process referencing AS 5039.2.
- Certification labels or documentation supplied with the finished door.
- A stated warranty period covering both the product and the installation.
Non-standard frames, raised sills or ramped entries often call for a specialist on-site assessment rather than a generic fit, since these details change how the frame and mid rail are anchored.
Keeping your mid rail and hardware in good condition
A mid rail needs little attention, but a few routine checks keep it performing as intended. Look over fixings for looseness, check for surface corrosion or paint wear, and test that mesh tension and hinges feel firm rather than loose or stiff.
Between professional services, you can safely:
- Wipe down the rail and frame to clear dust, salt air residue or grime.
- Check screws and fixings are snug, without over-tightening.
- Lubricate hinges lightly if they start to squeak.
Call a professional if you notice sagging, a lock that is hard to align, or visible corrosion on fixings, and ask the installer to show evidence the repair or adjustment keeps the door within its original compliance rating. We offer service and repair for exactly these situations.
Choosing the right mid rail: a quotation checklist
Before you commit to a design, it helps to work through a short checklist with your supplier:
- Confirm the door’s intended use: maximum security, ventilation, or a balance of both.
- Decide on material and finish based on your climate and maintenance preference.
- Check the mid rail height suits your existing lock and handle centres.
- Ask for evidence of AS 5039.1 compliance and installation under AS 5039.2.
- Verify the installer’s licence and security agent credentials.
- Clarify the warranty terms in writing.
At quotation stage, ask directly: what performance standard does this door meet, who installs it, and what warranty covers the mid rail and locking hardware. A custom on-site measurement, rather than a generic size chart, is what prevents the fitting issues that come from assuming a standard clear opening or handle height.
| Checklist item | Why it matters |
|---|---|
| Intended use | Determines rail strength and infill choice |
| Material and finish | Affects corrosion resistance and appearance |
| Lock and handle compatibility | Avoids clashes with three-point locking systems |
| Standards compliance | Confirms AS 5039.1 performance rating |
| Installer credentials | Protects compliance and warranty validity |
Our approach to mid rail design and installation
We build every security door around a custom, on-site measurement, so mid rail height, lock position and handle centres suit the actual doorway rather than a standard template. Compliance with AS 5039.1 and AS 5039.2 sits behind every door we manufacture, backed by a fast turnaround and a workmanship warranty.
— MYBMC
Get a measurement and quote for your security door
If you are weighing up where a mid rail should sit or which material suits your entrance, a free on-site consultation gives you answers specific to your doorway rather than a general estimate. We measure, discuss lock and handle placement, and quote against AS 5039 compliance before any manufacturing starts.
Our range covers the materials and finishes discussed above, so you can match a mid rail design to your home:
- Aluminium security doors for a lightweight, corrosion-resistant option with broad colour choices.
- Stainless steel security doors for coastal or high-moisture entrances.
- Steel doors, flyscreens, window grilles and more for heavier-duty or alternative configurations.
Book a free consultation and quote through our security doors page, and we will work through placement, materials and compliance together before you commit to a design.
FAQ
What is the standard height of a door frame?
Door frame heights vary by manufacturer and property, so there is no single figure that applies everywhere. What does carry a fixed requirement is the clear opening width for at least one entrance, which livable housing guidance sets at a minimum of 820 millimetres.
What is an iron security door?
An iron security door is a door built with a wrought iron or steel frame, often featuring decorative scrollwork alongside its mid rail and security mesh. Steel options in this style combine a traditional look with the structural rigidity steel provides, and should still meet AS 5039.1 performance requirements regardless of the decorative finish.
How much does a standard Crimsafe screen door cost?
Pricing for screen doors depends on the brand, size, material and installation complexity, and is not something we can state as a fixed figure without a specific quote. We provide pricing after a free on-site consultation and measurement, since mid rail placement, material and hardware all affect the final cost.
What is the size of a standard screen door?
Screen door sizes vary by home and manufacturer, but the clear opening width needs to meet the 820 millimetre minimum set in livable housing design guidance for at least one entrance. Custom measurement remains the reliable way to confirm the right size for your doorway, since older homes often have non-standard openings.
Why does mid rail placement matter for locking systems?
Mid rail placement needs to align with your handle and lock centres so a three-point locking system engages cleanly without the rail obstructing the mechanism. Getting this wrong can mean a lock that is difficult to align or a rail that interferes with the latch, which is why on-site measurement before manufacturing matters.