Does anyone have any tips on extending a chimney? The fire box is gas logs and the existing chimney is brick. I would like to put a b vent pipe inside and grout it in but not sure how to give the grout time to set and not fill the entire cavity. Would rock wool or high temp foam be acceptable? Any other suggestions

The roof line has changed and the chimney is not tall enough to extend above the new ridge line.

The chimney does not necessarily have to extend beyond the ridge. The code is that it only has to be 24" higher than the nearest roof 10' away.

You'll save money/time & Code worries by contacting Gary Lemke AAA Overhead Door & Fireplace who will school you in what GAS codes require and install pronto for fair price what you want. This is not DIY, which may already be costing you more than what Gary will.

I will give Gary a call but im in Dallas.