It’s a bit outside my experience (limited to getting a French antenniste to aim the existing dish here at 28.2 °E and an understanding that south of the Villaine you are probably going to need a bigger dish than 60cm).
By “Sky dish” do you mean a mini-dish?
Do you want a set-up which will support Francesat and Freesat?
Hi Paul.
Yes we want to keep our existing set-up that gives us all the UK free to view channels via our imported Sky box and Minidish. We can also get the French terrestrial channels, but we get a better signal from the Britanny transmitter than from Normandie. So we would prefer to get our local news via satellite and also watch movies in VO (Not available on terrestrial.)
It seems as if Eutelsat 5W has a much weaker signal than Astra, so I suspect I need a French dish and wonder if 60cm is big enough, or will I have to install something more massive?
Can I ask how you get the French terrestrial channels. We have free sat for uk tv. Not sure how to get anything else. Thanks
I’d have thought your best bet would be a 60 cm dish and a twin LNB setup so that one LNB gets the Freesat/Sky signal and the other gets Eutelsat
Teresa - does your house have a TV aerial?
It may even take a 90cm dish.
Just an old-fashioned Yagi antenna with a cable that plugs in to the back of the TV. Like everyone used to do before satellite. 
Not quite with me there. The satellites are in different locations, so I need two dishes. And motorized is too exoensive and complicated for this old UK pensioner! 
Our local BricoCash sells 60 & 80cm dishes, so I suspect that those sizes are best suited to the local area. But it is interesting that an additional 20cm almost doubles the surface area and presumably also doubles the received signal strength.
Shouldn’t need two dishes, with 33° of separation there should be room to have a single dish and two LNB’s. Yes an 80 cm dish will give more signal - I think it’s 2.5dB more remembering that relative signal strengths are on a logarithmic scale.
It’s probably quicker to talk to an antenniste about your requirements.
Mat your 90cm comment sounds like you have experience?
We have an arm attached to the primary LNB so we have Freesat and French tv via the orange decoder box from one dish
Here is a link which shows how a multi-LNB setup works.
Thanks Paul, that is very interesting and l didn’t know it could be done. But as I already have the Sky set-up working perfectly, I would prefer to leave it alone. If it ain’t broke… Also, the multi LNB option is likely to be rather more expensive than a dish with a single LNB. I also wonder if locating the LNBs off centre has any effect on signal strength or quality. Maybe the dish would need to be larger to compensate?
Yes, the fact that you aren’t using the main focal point does reduce signal strength. Whether you need a larger dish to compensate depends on how marginal the signal if it is quite a strong signal in the first place you might be ok. Yes a multi LNB setup will be more expensive as there are more bits to buy and it’s a bit more complex to set up. But it avoids having to adorn the house with multiple dishes. That said I do get what you are saying about your existing Sky dish working and not wanting to break it - but it no longer meets your requirements.
Edit: Mike might be interested in this thread which discusses exactly what he wants to achieve - reception from Eutelsat on 5W and Astra on 28.2E - looks like it can be done but 33° is a big stretch so might need some faffing and fiddling.
I suspect he will be back to tell us that he went down the two-dish route 
We live in the Gironde and have both UK Freesat and French sat. TV with two LNBs on one dish. How did we achieve this? We went to our local TV shop told them what we needed and do you know they came out and fixed it for a very modest price. Why do people faff about when the expertise is readily available locally?
Maybe cost David ?
I got away with a 60cm dish near Limoges but need a 90cm dish in Albi. French tv is supplied by Orange in their Zen package with internet and landline etc.
Cost? The desire to understand the problem and do the job yourself? The warm glow of success when you do that and it all works?
Cost is a tricky one, of course - trying to do the job yourself could wind up dearer because of false starts and wasted purchases whereas, hopefully, getting the professionals in should do the job right first time.
I believe I have suggested talking to an antenniste twice in the thread 
I did say modest cost Peter. TV from Orange would be nice but we’ve got to wait until 2021 for the fibre to arrive.
We have Orange internet by the landline but the Orange tv is via a satellite dish, apparently fibre will arrive within a few months.
I have always installed the satellite dishes wherever we’ve been mainly to save money but this time asked a local Albi firm to supply and install the 1 metre dish (the minimum requirement was 90cm) plus I needed other gubbins to make it Orange tv via satellite work and the cost was over 500€ which I don’t find ‘modest’ at all…
Right Paul, I can live with the two dish solution. The Sky Minidish is virtually invisible on my lean-to shed, so the only problem is finding a way of camouflaging an 80cm French dish. I wonder if a coating of cow muck would do it? Like they do with new roof jobs in the Cotswolds…
As far as DIY is concerned, I have always thought that it makes sense to foul things up myself, rather than pay someone a fortune (plus TVA) to foul things up for me. And when it works out, the sense of achievement is worth as much as the money saved.
I will post some feedback - whatever the outcome. 
Finally went and bought a 27€ no-name 60cm dish and LNB from BricoCash. I also got a Chinese dish finder on eBay for 5€.
Set the approximate elevation before fitting the dish. Using a compass, I lined up a wooden lath on the ground to the azimuth for my region. Mounted the dish on the front of my lean-to shed, lined up the LNB feed arm by eye with the lath and found, using the dish finder, that I was only a couple of degrees away from the satellite.
I am getting 67% signal strength according to the meter in my Fransat box. No idea what that actually means in dB but I am getting perfect pictures. I may try some tweaking later, to see if I can get any improvement.
I have to say that Eutelsat 5W seems to be harder to find than Astra 28.2°. Maybe it is a weaker signal, but there is very little tolerance on adjustment. When tightening the clamps, I noticed that the signal would begin to drop off if I wasn’t careful to tighten the nuts on each side alternately.
In conclusion, I have to say that the satellite finder was a very good investment. It has sound as well as a visual scale and can be hung from the feed arm, leaving both hands free. It even has an illuminated scale in case you should want to use it at night! It is sensitive to all frequencies, so you don’t have to pre-select the satellite you are looking for from the menu on the receiver. And finally, by making the job easier, you are less likely to fall off the ladder (an all too common accident) and that has to be a good thing!