Is There A Standard Door Thickness
Updated: Oct 9
Standard door thickness in Australia
I was asked if there was a standard door thickness? An interesting question as most door handle manufacturers generally supply fixing screws to suit 35mm to 45mm thick doors. Some extend to 50mm but generally they are less. Today though more doors are being made thicker, or are they?
Depending on where you buy your doors from, you will find the thickness of a door does vary. I can't find reference to a standard door thickness requirement however there are off the rack door thickness sizes, from 32mm to 50mm, but even these can vary. Doors that fall outside of the 'standard' range (or not on the rack) are considered to be non-standard, and will either require custom framing and hanging, or will need to be modified to fit the space.
Common Door Size
In Australia the most common standard door size is 2040 x 820mm, and 920mm, but there are other sizes that are popularly used, and door thickness varies.
In Australia, the sizes of exterior doors are somewhat standardized. This helps homeowners control their costs when building or renovating a property. Standard exterior frames are designed to hold doors 2040mm high and x820, x870, x920 or x1020 mm wide.
Door manufacturers in Australia do produce doors in common standard sizes. This allows the customer to choose doors in a variety of colors and materials. When the door they like will fit the door frame the choice is easier. Here are a few door sizes: 2040 x520; x620; x720; x770; x820; x870; and x920. Depending on the actual frame size, doors can be machined to size.
Standard Interior Frame Dimensions
Interior doors are smaller. The height for all interior doors must be minimum 2040mm. The standard width for interior doors is 620, 720, 770, 820, 870 or 920 mm.
If you are renovating or building know your door frame measurements. Interior doors are easier to install. You can modify the door frame according to the door size.
Panel Door Sizes
Interior panel doors have a standard size. Height is 2040 mm, x 620, x720, x770, x820, x870, or x920 mm. The thickness can vary depending on where you purchase the doors.
Panel doors are usually are made from wood and have vertical side styles and horizontal rails. Panel doors are known as a hollow core door. This reduces the material needed for building a door. Ultimately it cuts cost.
Flush Door Sizes
A flush door is 2040mm or 2340mm high and has a width of x420, x460, x520, x620, x720, x770, x820, x870, x920, or x1020 mm. The thickness can vary depending on where you purchase the doors. Flush doors are front and back surfaces that are largely flat. Made of wood sheets making them more affordable for interior doors. The surface of the door can be painted. Allowing color matching to walls.
Bifold Door Sizes
The standard height of a bifold door is generally 2040mm. The width depends on the number of panels being used. For example if 2 panels are used the width is 1800mm or 900mm each panel. For 3 panels x2700mm, for 4 panels x3600mm and so on. The thickness of the door does vary again, dependent on where you purchase them and how many.
Bifold doors are folding doors. They open by folding back in panels. Primarily used in smaller size rooms to save space. This type of doors is expensive due to its complexity in construction and installation.
Glass Door Sizes
Glass doors are available in varying sizes. Again the height will be around 2040mm. Common widths are x520, x620, x720, x770, x820 or x870mm. Larger glass door sizes are a made to order option for specialty projects.
Glass doors are popular in homes to bring the outdoors inside. Glass allows the natural light in side. Glass doors make the room feel and look bigger. Glass doors are usually with either a single sheet or with multiple glass panels. They can be framed or frameless. They can also be folding or swing type.
Fire rated door leaves are manufactured with a pyropanel fire resistant core, these doors are fully tested and certified to AS1530.4 and AS1905.1, and are available in a variety of sizes and finishes in 30 minute, 1 hour, 2 hour and 4 hour fire resistance levels.
Fire door sets are available in pairs or singles, and with panels over, including 38mm and 48mm (nom) thickness.
30 minute and 1 hour door leaves are of ‘no metal’ construction type, allowing for easing hanging and lock preparation.
However the thickness of the doors can and does vary. Ignoring 'standard' thickness because I can't find a standard other than from different door manufacturers. So lets see what you can buy off the rack. Door thickness off the rack varies from supplier and manufacturer across the board. The overall standard size of a door you will find on most door supply racks. However the thickness of those doors can and do vary. Doors from as thin as 25mm, growing to 32mm, 33mm, 35mm, 38mm, 40mm and 45mm variants.
Handle Height Matters
Regardless of the size of the door, the Australian Standard AS 1428.1 (Design for access and mobility, Part 1: General requirements for access) recommends that the height of the handle should fall within 900mm and 1100mm above the floor. This is around waist height for the average adult. Generally speaking, only much older doors or those installed for a special purpose will deviate from this recommendation.
What is the standard door thickness
You will find some door suppliers stating that the standard door thickness is 35 or 40mm while others will tell you its 33mm depending on what they have on their racks. The bottom line is door thickness does vary. Maybe back at the industrial revolution when machines took over and they could machine a door to 35mm or 40mm thickness it became the off the rack standard. But now a days when there are so many imports and suppliers, the 'standard' off the rack door thickness has varied.
Does door thickness matter
So, does it matter how thick your door is? When the door is closed how thick does it look? A closed door looks... flat. An open door is something you walk through and close behind you. When its closed it looks... flat.
When the door is closed how thick is it
The issue you will find is that manufacturers of door hardware are left in a quandry. There are numerous door thickness' and only so many fixing bolts they can supply to go through the thickness of a door.
Supply and Demand
So the manufacture in their wisdom supply either 45mm (some 50mm) tie through bolts so that they can be cut down to size. Because door thickness does vary it becomes difficult to cater for all possibilities. And for the sake of a hacksaw blade, you can cut back when necessary. Why, even Lockwood state door thickness to be anywhere from 32mm to 50mm as standard for there door levers.
Unfortunately the thickness of doors is uncontrollable. Recently we were faced with a door that was cladded to the point it reached 170mm thickness. When it was closed, it was still flat.
Most entrance handles or pull handles come with 110mm bolts when used on wooden doors. The bolt head depth is around 25mm and the thread into the receiving leg is around 25mm leaving 60mm for door thickness.
Again here we have a problem. If you door is more than 60mm thick you will probably need longer bolts. In these situations what we try to do is supply suitable ferrules and a bolt long enough for the job. Not always easy or available. We may have to create something to make it work.
The benefit of a thick door
If you owned a castle and the front gates were extra thick it would deter would be invaders. However having a thick door on your entry to your house is perhaps for show only. If the walls do not correspond with the door thickness not much is achieved. That's not to say you shouldn't have thick doors if that is what you want, I just don't see the benefit when the door is closed.
Ideally thick walls and matching doors would keep outside noise to a minimum. But there are other ways to achieve the same result by using door seals for example. The other downside to having a thick door is that you still have to open it.
Opening a thick door
Opening a thick door can be difficult if the door is not hung effectively. If hinges are the hanging point the weight of the door will require strength to close and open it. Ideally a floor pivot system would do the job nicely allowing easy open and close access. We have a solution for that too.
Do doors come in different thickness and is there a standard size? I guess the answer is some do and others don't. You will find some door manufacturers will use standard sizes in their industry. Whilst others will use different sizes in their manufacturing. A lot will depend on where you purchase your doors. Were they made in Australia or are they imported. Most imorted doors tend to vary thickness.
As long as the door is equal too, or grater than the frame size, it can be made to fit. And that is more important than having a door that is too small for the frame.
Whatever the scenario, we will try our best to accommodate your needs and requirements when you purchase door handles and entrance handles from us. We will ensure your door opens and closes behind you.