It's a gas start fireplace, not more than five years old. The gasline is ran, but there is no ingnitor, and it's capped.

How big is hole?

Use fast drying hydro cement. It is denser then normal concrete and drys to touch in about 10 minutes. Some dry faster.

Chuck

It's a 3/4 inch gas line, and the hole is 1 1/2 inches. Don't know if that changes your answer or not.

Answer still the same. Use hydraulic cement to seal around pipe. Push as much as u can into hole.

Chuck

Thanks. Much appreciated!

Good luck

Chuck