Alcove "ceiling" question

[jbrown9709]

Hi Fellers (and ladies). I have in my grubby little hands a PE Alderlea T5, to replace a propane builder grade fireplace in a framed (fully interior) chase. (see photo, please excuse mess... kids..) Chase is 6' x 2' up to vaulted ceiling. We were originally going to demo the chase and install a brick veneer backer and hearth, but the ceiling drywall repair would be... challenging. Having observed some photos, the idea of an alcove install that would maintain much of the framed chase begins to appeal. But... I'd prefer not to be open for the full 84" from hearth surface to top of alcove as required in install manual. My question is can that be lowered (either entirely, or just on the face (leaving a cavity behind) if done completely with non-combustible materials (steel studs, cement board, brick veneer) The manual for my T5 does allow for reduced clearance per NFPA 211. Attached is photo of current install and page from t5 manual. Thanks in advance!

 

[begreen]

The gain from 14" to 12" with wall shields isn't worth the hassle IMO. Honoring the 14" side alcove clearance requirement brings it to a 53" opening requirement. Make it 60" for a little wiggle room and room for opening the trivet top wings. The ceiling height is more of a grey area. Whatever the design is, make sure it passes muster with the local inspecting authority. There is a caveat in the manual:
NOTE: local/national codes or regulations may override some guidelines in this manual

If the lid is entirely non-combustible (structurally and covering, then lowering it should not be an issue. You will want to avoid making a heat trap. How high an opening are you considering? We did have one fellow years back that created a full metal stud enclosure with a tile or stone skin that had the alcove ceiling at 84" but the opening at like 48". He put a blower on the stove and a large register grille at the top of the cavity to vent trapped heat into the room.

 

[bholler]

I really think this is a question for PE. I could see that lowering the ceiling even if non-combustible itself could direct more heat onto the combustible walls. But I am not sure so I think a call to them would be wise.

 

[jbrown9709]

Thanks for the input. I'd considered the cavity with vent idea, but in the end, I think we'll bite the bullet on the ceiling repair and go with a more conventional install. Cheers!

 

[begreen]

I really think this is a question for PE. I could see that lowering the ceiling even if non-combustible itself could direct more heat onto the combustible walls. But I am not sure so I think a call to them would be wise.

Indeed, the walls would also need to be non-combustible. The aforementioned alcove had metal stud walls clad with cement board and I think skinned with a ledger stone veneer. There were no combustibles involved. I'll see if I can dig up that thread, but it was several years ago.

 

[kennyp2339]

It all has to come out anyway, along with the existing chimney, personally I'd rather see a long straight double wall black pipe to a ceiling support box then a padded out box with fake rock glued to it making it look a millennial cave.