I'm building a greenhouse that has rock as a base. It's uneven and on half of it, I will fill with gravel before casting a slab inside the greenhouse. Do I need to plaster Leca on the inside of the wall, or can I fill with gravel directly against the Leca blocks? Does the plaster have any function besides being a smooth surface? I would prefer to shovel in the gravel without plastering... I will plaster the outside later - but the same question applies for the parts that will be below ground. I have about a 30 cm gap between the wall and the surrounding lawn. Can I fill it with gravel there without plastering?
