Thanks for the comments, the principles on concrete are the same, you can either fully stick down using a product like Mapei G19, or use a slow set grass adhesive and use a mastics gun and stick the product around the perimeter.

Thanks for the comment, the trouble with compacting after laying the grass, is that you cannot identify "low spots" that have been compacted more than some areas, due to softer ground/conditions. If you compact before laying the grass, you can fill in these low spots with more sand/hardcore and repeat the process until you have a perfect surface to lay the artificial grass on.

Had this grass on sand for 2 years, and my previous grass on sand for 5 years (only changed it as we re-landscaped the garden), and I never got a smell from it. I think it can be more on the drainage beneath the sand (e.g. if you don't have at least 30mm of hardcore beneath the sand, any liquid can't drain through the sand and could smell). If you have grano, any liquid will pass through it and "settle" on the mud below. If you can afford grano and have access to it, it won't harm the installation and give you more of a chance on the smell not becoming an issue.

Basically you need to dig down to hard soil, compact it, then you want about an inch of type one then about 10-20mm of sand, again the compact and level all of this.

38mm, don't buy grass on thickness, its best to buy on density.

No, the underlay and grass allow water to pass through. So does the sand and hardcore. This job has been down nearly 2 years now and has not flooded or shown any movement. The glue used for the join is a 2part epoxy that will not be effected by heat or frost.

Luke Crooks thankyou for replying I am planning to lay some, have seen various underlay being used

Marcos J yes, it’s a filtration underlay.

@@lukecrooks8470 Silly question i know....but i thought this was Cloud 9 for carpet underlay and just had to double check..Cheers!

Cloud9 is a brand, you need to ensure you are using the Eco Cushion product from cloud 9