The next process was to have the Polyurethane Foam sprayed. I employed a company by the name of:-
P Homer Ltd, Newtown, West Pennard, Glastonbury, Somerset. Tel 01458 832955.
http://www.insulationsprayfoam.co.uk/
Andy the owner of the company had not sprayed a pond before, he spends his time insulating roofs of commercial premises and insulating boats. But on explaining what I was after, away he went with his spray gun.
As you can see from the photo above, there is no need to render the pond as the foam builds well and covers the block work without problem.
The foam is sprayed in a thin layer and within seconds, expands 30 times it's volume. My quote was for a 25mm thickness, but due to it being difficult to judge, the thickness came out at around 40mm.
This photo shows the finished foam, ready for
sanding. 
Sanding of the foam is very easy. I used a belt sander for rough removal and the then switched to a flatbed sander for final finishing.
Photo on the left shows the un-sanded foam, on the right the finished foam. Very dense.
Once all the sanding was done, I removed the ply board that I screwed to the wall to form the window frame.
The pond was now ready to be glassed. Two layers of 450 gram glass was applied, with staggered joints. Glass was also applied into the window frame, so that there would be a nice flat and firm surface for the window to be bonded to.
Once the GRP (Glass Reinforced Plastic) had been applied and it had cured, the roof was removed. The next process was to cut and set the capping stones on the top of the pond. I spent along time trying to find the capping stones I wanted and finally found a source in West Wales. The stones chosen are Welsh Blue Pennant.
Below I have started the long and difficult job of cutting the stones to suit.
Once the stones had been cut to suit, they were cemented into place.
Then the final flow coat was applied and then the big fill-up! 14 days later the pond was full. It has run this summer with temporary filtration sat on the side of the pond. Due to setting up the koi farm, completion of the pond has had to take a back seat.
Last updated 181104.