Hi @shmo,
Thank you for your question about replacing an external door.
For this size of opening, you'll want to use a 2040x820x35 external door.
For external doors, people usually prefer to use solid doors as they are much more difficult to break down. This Hume 2040 x 820 x 35mm External Door Duracote Flush Solicore SCX1 has an MDF core and is an extremely solid option.
There are lighter honeycomb core doors such as this Hume 2040 x 820 x 35mm External Door Duracote Flush X1, but they are a lot easier to break down, so for security reasons, people often prefer the solid options.
Before hanging the door, it needs to be trimmed down to fit the opening. This can be done with a circular saw and a straight edge as a guide. You can use the measurements of the old door to replicate the old one and transfer the hinge locations to the new door.
As it looks like your old door used butt hinges, you'll need to rebate the hinges into your new door, so they sit flush with the surface of the timber.
It is also worth painting the door before hanging it as you will have access to the top bottom and sides which along with the faces of the door, need 2-3 coats of paint. If the bottom of the door is left unpainted, water will get in and cause the MDF face of the door to swell and delaminate.
Once the door is hung, you'll need to install the door lock and then test the function.
Have a look at How To Hang a Door for some guidance.
You might also like to consider our Door Installation service.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
