Silpat too big, safe to use in oven still?
I use my silpats in very hot ovens, I think they are made to withstand extreme temps so I would probably guess yes, it's safe.
Another thing you can do is trim your silpat with scissors. They cut quite nicely, with no risk of unraveling. I've cut a full sheet size silpat in half to fit my half sheet pans and they still work fine and are in good shape.
It might not be.Contact your ovens brand for really accurate info.
I know it would be detrimental to use that way in my ovens,all have circulating shelf/bottom designs and a complete fit would interfere.
Some manufactures/brands have warranty voids,noted in the manual due to finish damage on the oven floor.