How to fix hollow uPVC board to soffit

[shd1970]

Can anyone offer some advice and a solution to this challenge please

I'm capping over my fascias with 9mm Eurocell capping, and also using hollow soffit boards
You will see from the attached photos that the front of my house is also tiled



The fascia board comes down 65mm from the soffit (blue arrow)
I plan to sit the hollow board on the capping fascia board "lip", but i'm struggling to understand how i can secure on the tiled side ?

I was therefore thinking about securing a 65mm batten of timber to the soffit on the tile side (green box) and then attach a piece of plastic trim to slide the hollow board into so the hollow board sits level front to back

But, the soffits are cement boards and likely has some asbestos content so prefer not to drill or touch them

So am i missing something here ?
Is there a better solution for fixing the hollow boards up underneath please ?

Many thanks in advance

 

[23vc]

Glue it? Can’t really see any other option other than fixing through the existing soffit

 

[shd1970]

Glue it? Can’t really see any other option other than fixing through the existing soffit

I guess i could glue it, but had hoped that there was a better fixing solution due to the flaking paintwork and i would prefer to not have to start tidying them up to make sure the glue "stuck"

I guess the only other way would be to fix 6 or so 65mm x 25mm x 330mm battens screwed onto the back of the fascia board, but it would be a struggle to get them tight due to the tiles

 

[23vc]

How would you support the other end of the batten?
I’ve used J trim for this screwed to a batten which is fixed to the gable noggins. I guess you could possibly try to glue a j trim on to the existing soffit if you reckon that’s got more chance of sticking to a small area

 

[shd1970]

How would you support the other end of the batten?

That’s the only flaw so was thinking an “as tight as I can cut it/fit it to the tiles” batten, with 2 decent length screws through the fascia

Not ideal but not sure what else without drilling the soffit