Pond liner

[DerSchoeneBahnhof]

Quick question, is pond underlayment on compacted 3/4 crushed gravel ok?

And also if the sides are concrete blocks, can the underlayment be just on the bottom or need underlayment on the sides as well?

Thanks!
CG

 

[combatwombat]

Absolutely cover the sides. And knock any boogers off your block wall/chamfer sharp edges before placing underlayment.

 

[GBBUDD]

Underlayment is not all the same When you hear underlayment, non woven Polyethylene geo textile they are not all the same they are rated by the oz and also there tear strength. i have used 8 oz with good luck in protecting the liner from rocks roots and say concrete block. You can go with a higher number if your soils are hardly that when you start getting into 12 oz or more that is some crazy tough stuff and it's even a nightmare to cut. i prefer to used sheers.

As to block as mentioned you'll want to scrape off any protrusions but you also will need to at the corners ease over the edges with a scarifier or a masons wheel on a grinder. if you have built a rounded wall to parge the steps and at the bottom whether you use a good underlayment or not neither product like to make 90 degree corners so i also will round the bottom corners with a bead of mortar

 

[Mmathis]

As to block as mentioned you'll want to scrape off any protrusions but you also will need to at the corners ease over the edges with a scarifier or a masons wheel on a grinder. if you have built a rounded wall to parge the steps and at the bottom whether you use a good underlayment or not neither product like to make 90 degree corners so i also will round the bottom corners with a bead of mortar

I bought an angle grinder. Worked great to get rid of sharp edges and protrusions!

 

[DerSchoeneBahnhof]

Great, all good advice. Round bottom corners, scrape off sharp edges / protrusions.

Thanks!
CG