My garage is built on the side of the house because my garden is quite small. I can't get round the side so have to go through it. The back is completely open because my cars have been too long, the front door is an up and over. I now have a small car and want to fit a pair of wooden doors to the back, which I have already bought and started to paint.
The opening is wider than the door frame, which I knew I would have to make up with some form of packing and would like advice on suitable fixings.
I need to fix the packing to the brickwork and the frame to the packing. I would really appreciate any advice please, particularly with fixings.
I'm also thinking of using some suitable adhesive between the packing and the brickwork to help secure it.
The opening is about 2.5 inches wider than the frame.
Any advice would be greatly appreciated.

How big is your packing likely to be Bob???  If less then 50mm screw your packing timber to the door frame first, then you can use plastic shim packers to true everything up if you get the broadfix brand type, they are a ribbed horseshoe shape to allow you to hang over the fixing as you screw it in.

The best method is a direct masonry fixing, varying sizes

https://images.app.goo.gl/R6W6ans2Ekf11giaA

These you basically drill your hole to the required depth and a bit more, and rattle them straight in, quickest easiest way, you can tweak them up to pull the frame square and upright as well.

I wouldn't worry about and adhesive, set the frame about 20mm back from the front of the brickwork and once the frames in square and upright and the door closes nicely a bead of silicone all the way round would be sufficient, if you have gaps bigger then a few mm a squirt of expanding foam around the frame to the brickwork will help firm everything up. Once that's gone off, usually the time it takes to enjoy a brew, it can be cut carved or squashed inside to allow you to silicone over the top.

If the frame is cill less and sits onto the concrete a piece of plastic membrane underneath the frame legs will help moisture being sucked up through the open grained bottom.

Plenty of good videos on youtube worth watching to help you out 

You've just put the measurements up, I'd anchor to the house wall with the hinge side of the frame,

2 options

Fix the packing timber to the other side of the opening and then fix your frame to that, anchor fix the packing piece to brickwork and then frame to packing

Or

Machine suitable timber packing to equal the frame to the centre and use a bigger fixings through into the brickwork,

Thanks for that Craig? The packing thickness would be 35mm. Because it's not very thick do you think it would be better fixing it to the frame first?
This then would give a frame upright thickness of 100mm each side,(it's 65mm at the moment), so what length of screw would you suggest to go through the frame and into the brickwork?
I've looked at a few on YouTube but none have used a packing piece, the width of the frame has always been the same as the opening.
I have seen those screws before, I understand they screw straight into the brickwork, after drilling a pilot hole fist, is this right?

Id screw that size to the frame first Bob, probably a 175mm fixing for that, just make sure you've got a drill bit long enough to allow you to fix it 

Yeah drill your hole straight through, the fixings want to fix straight into the brick rather then the mortar joints, ideally you want at least 4 fixings per side of the frame

Thanks you have been a big help. I'm much happier now and can proceed with confidence. Let you know how it goes.👍