# Chase for direct-vent fireplace



## ellenjo53 (Feb 18, 2010)

We had a direct-vent fireplace installed on an interior wall in a newly constructed home.  The fireplace leaks a lot of cold air at the bottom -- we've caulked around the soapstone face and taped where the gas line comes in.  LSS, the chase is not enclosed -- it is open to the air space above this sun room area in our house, and merely has insulation (in the ceiling above) laying on top with the vent pipe passing through the insulation.  The builder is trying to rectify this situation for us, but I'm not sure that he knows what he is doing.  I've read about proper construction of a chase for direct-vent fireplace, but am wondering what the thoughts are in the Hearth Room.  Many thanks.


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## begreen (Feb 18, 2010)

Moved to the gas forum for a more targeted response. 

Was this installation inspected? I would expect a metal firestop if the vent passes through floors.


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## ellenjo53 (Feb 18, 2010)

There is a firestop around the vent pipe, but the chase is open at the top.  In other words, the firestop is installed around the pipe, but there are open gaps all around the firestop because the top of the chase is not enclosed.    I've had our local building inspector look at it and compare it to the installation manual that came with the Heat & Glo fireplace.  Heat & Glo says that the chase should be sealed and treated as a part of the interior of the house to prevent drafting.  I am also reading (on a Vermont Castings website) that there should not be any exposed insulation inside the chase that could fall onto the firebox.  In fact, this has already happened, and my builder is planning to "fish" it out of the chase.  My feeling is that the fireplace needs to be removed, the wall opened up, and the chase constructed safely and properly.  They want to attempt to fix it from the crawl space above the room by enclosing the top of the chase only -- no sheetrock on the inside.  Any thoughts out there?


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## DAKSY (Feb 23, 2010)

ellenjo53 said:
			
		

> We had a direct-vent fireplace installed on an interior wall in a newly constructed home.  The fireplace leaks a lot of cold air at the bottom -- we've caulked around the soapstone face and taped where the gas line comes in.  LSS, the chase is not enclosed -- it is open to the air space above this sun room area in our house, and merely has insulation (in the ceiling above) laying on top with the vent pipe passing through the insulation.  The builder is trying to rectify this situation for us, but I'm not sure that he knows what he is doing.  I've read about proper construction of a chase for direct-vent fireplace, but am wondering what the thoughts are in the Hearth Room.  Many thanks.



You have a cold install on an interior wall? That's pretty uncommon.
Externally installed units generally exhibit cold drafts which are 
in fact reverse convection air movement.
If you install a gas fireplace on an interior wall, the only insulation 
required is in the ceiling above the unit & below the attic space.
Plywood firedecks are required at every ceiling/floor level (8 or 9ft),
with firestops installed in each deck.
That being said, you should probably have an insulation shield where
the vent pipe passes thru the insulated area.
If you're getting cold air thru the gap between the firestop & the vent pipe,
seal it with tape-style stove gasket or aluminum tape.


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