Right final shot at this,
Paving laid, (pre-sealed which should make no difference) then grouted.
He didn't leave enough time for the medium used to lay the paving to dry, (Limestone wicking up moisture) then grouted so again not enough time for the grouting to cure before starting to seal the paving, plus with the over kill of applying coat upon coat of sealer the whole area is saturated and not drying. Also the temperatures to low to seal anyway, with it being a conservatory to cold maybe ?Also maybe not taking off any excess sealer (pooling) so all leading to a fail?
Even if this is not the right answer, tell us the bloody answer 
Roger..
I found your answer, so, first of all...the REAL answer is the Tiler is not quiet the professional that "The Almighty" claims he is.
The Job was clearly rushed and the lack of knowledge didn't help.
HOWEVER, Chris's question is/was....How do you correctly apply sealer?
The temperature of the working area needs taking into consideration.
Adhesive dried (most modern adhesives are 'trafficable' after only 2 hours) fully cured 24 hours and then groutable.
Grouts, again, similar to adhesives in that they are cement based, I would suggest a further 24 hours before applying the sealer.
Now, this is where it gets interesting. Applying coat after coat of sealer, saturating the area and not allowing each coat to dry (Rogers words).
On a course in London which I did, they suggested flooding (saturating) the area and letting the sealer go into the stone, then wiping off the excess. I think the question is;
How are sealers properly applied?
I suggest water based sealers can be used as above and the excess removed with a sponge.
Now, oil/spirit based sealers will not behave in the same way using a sponge...so, what would you use Roger, (or anyone else who is still following this thread!!) to apply a spirit/Oil based seal?
You may remember I posted on here about using a sponge, Tony's reply was..."SPOT ON."
It later became apparent that (according to The Almighty) that was a joke! With jokes like that, it looks like Michael Mcintyres' career is safe!!
I think there are still some questions that need answering to avoid any costly mistakes.
Just for the record, has anyone ever done a Terracotta Job?
Cleaned the floor...let it dry.
Oil the floor using a sponge and Boiled Linseed Oil??? This is where the fun can begin. SOME sponges spontaneously combust...so, my advice is..get that sponge as far away from the job as possible, or you risk burning your customers house down
