Remod grow room

[Jointer65]

When installing Mylar does it need to cover ceiling and walls or just walls

[JohnEmad]

As the lights usually shine down I would only be concerned with walls if it were me..
I think tents are covered everywhere due to ease of manufacturing and using the same material.

[uncledoug]

I would also cover the floor.

[Tersky]

It depends. Is your ceiling painted with white waterproof paint? Then you are ok. If not, then you may want to put mylar to not only to reflect light but to protect sheet rock from moisture.