Author Topic: No Return ducts from the floors & flex pipe for gas?  (Read 2945 times)

Offline zimme

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No Return ducts from the floors & flex pipe for gas?
« on: July 28, 2015, 08:22:27 AM »
Hello; I am doing a reno to replace the heating, AC system and knob and tube wiring. The house is gutted out for the work.

With respect to heating, my contractor is not installing any return ducts as I used to know, from the main and second floors to the furnace. He is relying on the space between the studs/joists and drywall as return ducts. He also does not tape the joins for the heating ducts. For the main floor gas stove, he is using flex tubing branched out from the furnace instead of the black pipe.

Upon enquiry, he said that is no longer required by code and not necessary. I personally prefer the old way with ducts, taping and use of the black pipe (this seems safer for  in my view). Unfortunately, I had no way of knowing this and did not specify it in my contract.

Any help will be greatly appreciated. Is it right that in Toronto Ontario Canada, return ducts, taping of the joins and black pipe connections are no longer required?

Kind regards to all. Thank you.


Offline Admin

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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #1 on: July 28, 2015, 09:47:32 AM »
Using thermopan on joists or blocking inside walls and using the drywall is the standard when installing return air in new homes.

Your house was built before the recent code changes so the new taping requirements would not apply.  We have to tape the first 6' of return air ducts and ALL the supply vents throughout the house on any house with a permit issued after December 31, 2014.

They should transition to rigid metal gas pipe to pass through the kitchen floor for the gas line.  Most CSST cannot pass through tile without being sleeved inside a plastic conduit.  With rigid gas pipe we just need to tape it where it passes through tile.  A gas flex connector would be used to connect the gas line to the stove.

Offline Porcupinepuffer

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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #2 on: July 28, 2015, 04:18:57 PM »
CSST, or copper is getting to be the norm, and is quite safe. You can't even walk in to any new homes in Quebec without parts of it being CSST... And almost all furnace re/re's are transitioned to flexible copper to eliminate the need for measuring and/or threading multiple fittings.
You mentioned he was running flexible tubing branched out from the furnace? I'm assuming up high at an elbow above the furnace where the line is larger?
Regardless, it has to end behind the stove and then a valve is to be installed with a 6' CSST connector to do the final connection to the stove. This is to allow the stove to be moved in/out for periodic cleaning/maintenance... Rigid pipe would be impossible.

Offline zimme

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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #3 on: July 28, 2015, 09:53:05 PM »
In my particular case, there is no thermopan. It is just bare joists (basement) as is with a sheet of metal nailed at the two ends across the 16” on center. It is waiting for the dry wall to seal the space and it opens to the main floor.

He made a second floor return, it is just an opening between the studs waiting for the dry wall to go up.

None of the supply ducts are taped.

For the CSST going to the kitchen, there is no conduit to sleeve in. And he drilled 2” holes on the 2x10  joists which were in my mind unnecessarily large for the yellow CSST he used.

The CSST branched out from an 1” (od) black pipe. There are valves on both ends. On the stove side, it ended with an appro 6” black pipe with anchors to fasten on the wall to accommodate the stove connector.

Will the building inspector usually upon inspection, rectify any short comings? My reno is about to finishing the rough ins and I am thinking of calling the building inspector any time soon.

Is there a HVAC code book for Ontario? Will you please direct me to the related sections?

Due to the age of my house then, as I understand, there should be actual ducting instead of thermopan.

Thank you all kindly.


Offline Attavior

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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #4 on: July 30, 2015, 06:33:05 AM »
behind the stove and then a valve is to be installed with a 6' CSST connector to do the final connection to the stove. This is to allow the stove to be moved in/out for periodic cleaning/maintenance... Rigid pipe would be impossible.

CSST actually can not be used as the final connection to the stove, it has to be the approved gas connector.

(B149.1-10)
6.2.21
Corrugated stainless steel tubing (CSST) shall not be used as a gas connector.

Offline Porcupinepuffer

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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #5 on: July 30, 2015, 07:30:46 AM »
Yeah. I meant gas connector since every connector I've ever seen looked to be made of steel, and I believe the maximum length you can buy them in is 6'. I have seen more than one job where guys did coil the yellow CSST rolls behind the stoves and used it as the connector, but this is completely wrong as all these types of CSST are made flexible to be installed and then left alone, and not bent and twisted repeatedly over time. Whereas the approved connector is made for that purpose.

Offline zimme

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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #6 on: August 13, 2015, 03:08:00 PM »
Building inspector came in. She pointed out the deficiencies. Now, my son could deal with the contractor on a solid ground.

Contractor was hard balling and not cooperating to correct what we thought was not right by common sense from the very beginning.


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Re: No Return ducts from the floors & flex pipe for gas?
« Reply #7 on: August 13, 2015, 04:31:53 PM »
A city inspector or private home inspector?  What kind of defficiencies did they find?