1st underground pig roast

[Filipino-Boy]

How important is the tin/metal sheet covering over the hole?

Our first thought was a piece of metal over the hole, and then covered with a big piece of canvas over that, and then dirt over the canvas to block any steam from escaping. Having trouble finding a good piece to cover it, and now wondering if just the canvas would work? Stretched out tightly with dirt on top. TIA.

I use a 3 mil or 5 mil thick plastic sheeting I think with dirt around the edges to hold in the steam you don’t need to throw dirt in the middle but you can use a thick tarp like the old military canvas type but you will need to cover the tarp entire tarp with dirt or sand