# Expansion gasket for replaceable firebox lining

**URL:** <https://forums.firespeaking.com/t/expansion-gasket-for-replaceable-firebox-lining/52>\
**Category:** Masonry Heater Construction\
**Created:** [January 19, 2022, 3:12am UTC](https://forums.firespeaking.com/t/expansion-gasket-for-replaceable-firebox-lining/52 "2022-01-19T03:12:10Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![dclaire](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.firespeaking.com/dclaire/32/194_2.png) [@dclaire](https://forums.firespeaking.com/u/dclaire)\
**Post date:** [January 19, 2022, 3:12am UTC](https://forums.firespeaking.com/t/expansion-gasket-for-replaceable-firebox-lining/52/1 "2022-01-19T03:12:10Z")

</div>

There is an expansion gasket between the 2 bricks of the side walls that create the firebox on courses 7-10 “which serves as a replaceable firebox lining”. My question is why the gasket doesn’t go around the back of the firebox also, if the interior firebox bricks need replaced?

---

<div class="post-metadata">

**Author:** ![max](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.firespeaking.com/max/32/5_2.png) [@max](https://forums.firespeaking.com/u/max)\
**Post date:** [January 19, 2022, 4:45am UTC](https://forums.firespeaking.com/t/expansion-gasket-for-replaceable-firebox-lining/52/2 "2022-01-19T04:45:15Z")

</div>

Yes, we usually put 1/8” or 1/4” ceramic paper between all three walls. I’m sorry if that wasn’t better drawn.