# Insulating a fire stop



## green acres (Nov 15, 2010)

I am installing a gas stove in my kitchen, [a Napoleon] and have boxed in the fire stop for the through wall install. I have a 9" by 10" boxed out opening, my pipe is 7 inch.  Instructions  say to install the metal wall flanges [inside and outside]  after pipe is installed. So  my question is can I put insulation around the pipe between the fire stop and pipe?  It is the style that the center pipe is exhaust and outer pipe is cold air intake. Just seems to me I will be getting alot of cold transfer if I don't insulate. Thanks Dave


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## fireplace tech (Nov 16, 2010)

no you should not put any insulation around the flue it is considered conbustable, but you should a hi temprature silicone around the flur where it goes through the wall sheild or firestop .that is code in some areas ,but it will also stop any draft coming through.


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## DAKSY (Nov 16, 2010)

You CANNOT insulate that area. You can wrap flat tape gasket around the venting where is passes thru the firestop to reduce the drafts...It's less messy than the RTV silicone & works just as well...


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## Wood Heat Stoves (Nov 17, 2010)

fireplace tech said:
			
		

> no you should not put any insulation around the flue it is considered conbustable, but you should a hi temprature silicone around the flur where it goes through the wall sheild or firestop .that is code in some areas ,but it will also stop any draft coming through.



even non combustibe materials cannot go here(ceramic wool for example)


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## green acres (Nov 19, 2010)

Thanks for the replies,  I guess I am going to attempt to make an insulating gasket for the  pipe flange on the inside wall.  Dave


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