I'm wanting to add a gas fireplace starter and a gas grill in a back yard kitchen. The plan is to tee off the 1" line in the attic, over to the outside wall, down, out, underground, and back up in the back yard. Total distance added will be about 90'. Currently powering central heat, stovetop, and water heater (In central Texas.) The grill will be 75,000btu. Question is about line sizing. Should I maintain the 1" until I come back out of the ground, and then tee to smaller pipe at that point? Am I going to run into pressure issues with this length of run?

I'm wanting to add a gas fireplace starter and a gas grill in a back yard kitchen. The plan is to tee off the 1" line in the attic, over to the outside wall, down, out, underground, and back up in the back yard. Total distance added will be about 90'. Currently powering central heat, stovetop, and water heater (In central Texas.) The grill will be 75,000btu. Question is about line sizing. Should I maintain the 1" until I come back out of the ground, and then tee to smaller pipe at that point? Am I going to run into pressure issues with this length of run?

Are you doing this yourself or hiring someone that's licensed and insured to do it?

Asking because if you do something wrong and the house burns down... they (the insurance company) might not honor the policy.

This is a long run and most gas systems are sized by total BTU load AND greatest distance from meter, so I'm betting that you are pushing your limits here at 90'.

Also note that underground gas piping requires a special gas pipe, so you'll want to check with your local plumbing supplier for details on this.

To tell you more I would need to size your entire gas system and that takes time beyond the scope of this forum.

Contact a local plumber or your plumbing inspector... perhaps they can help more, OK?

Mark