Securing/bonding celotex foam board to inside of pond???

[Essex_Andy]

So I will be using celotex board to ensure I have square sides and flat base/shelf etc when the boxweld liner is ordered. The insulation is a bonus, the previous wall was so out of square and poor mortar Im surprised it didnt leak or break apart years ago! So using pu boards with the new block and brick wall to sqaure the pond walls and base etc.

But, always a but, what is the best expanding foam to secure the board to block and clay?

I've seen black waterfall pond friendly foam that is rapid growing foam and also seen low pressure/low expansion foam.
Has anyone used either with good or bad results?

Also any places where there's a wide selection of coping stones? I want about 1/2 to 1" overhang to hide the liner top..making the coping stone around 30cm/1ft wide.

Thanks in advance,

Andy.

 

[Meyer Jordan]

I would look for something else to use as an adhesive. The expanding foam products are manufactured for the purpose of 'sealing' and may have very limited and undependable results when used as an adhesive.And because it is expanding it may very well push your celotex walls out-of-plumb.

 

[Essex_Andy]

Fully understand. The snag is where the board meets the block work and concrete the join will be flush but below the level of the footings/foundations the boards will against clay, which is anything but smooth.

 

[Angel]

liquid nails? if not gonna be in contact with the water

 

[sissy]

When they put the insulation board on the outside of my basement they used some kind of black stuff that looked like tar but had to be sprayed on .It was really sticky also .They used it also for the waterproofing membrane on the basement out side .Can't remember the name and wish I could .

 

[Essex_Andy]

Sounds like a liquid damp proof material???

 

[sissy]

Not sure but they put this stuff over it that had bubbles in it that directs water away from the foundation and then spray it again to put the insulation board on .I know it was really sticky because I had to just touch ,told not to but well I did .Had it on my fingers for 3 days of washing the stuff off my fingers .Even tried the goo gone and still there .I know it was also featured on a show here called This Old House .