"铺以瓦" can be translated as "covered with tiles" or "paved with tiles" in English, depending on the specific context and the intended meaning.
If you're describing a roof or a surface that has been covered with tiles for protection or decoration, "covered with tiles" would be a suitable translation.
If you're emphasizing the act of laying down tiles to form a surface, "paved with tiles" might be more appropriate, though this phrase is more commonly used for paths, walkways, or floors.
In most cases, especially when referring to a roof, "covered with tiles" would be the more natural and commonly used expression.