Decking over a concrete patio

[jrussuk]

Hi
I want to deck over a concrete patio and wondered could I lay the deck frame directly onto the concrete or should it be raised?
If it needs to be raised what's the minimum height can I raise it.
The concrete patio has good drainage and water doesn't puddle on it when it rains.
Many thanks

 

[r896neo]

you can sit it right on it. Ideally sit it up a fraction on something soild but that won't wick water like plastic shims.