Romex embedded in spray foam insulation

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Rjryan

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Trophy Club, Texas
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Master Electrician
Has anyone seen a temperature study of Romex embedded in spray foam insulation? Has anyone experienced heat related problems with Romex embedded in spray foam insulation?
Saw the July 28, 2021 Post, but it did not have a temperature study or conclusive results. Watched a You Tube video by Canadian UL dated 1998 where the wire temperature under full load reached the maximum allowable temperature of the wire when embedded in foam insulation. Am I missing a load adjustment for Romex in foam or a restriction in the NEC?
 
The only problem I have herd of is with applying the commercial style or whole house spray foam around existing wiring that is 'made up' or existing.
The spray foam can pull connections loose in boxes and foam thru holes and boxes and fill them with foam.
I have found can lights filled to the trim, attic/crawl space j-boxes buried and conduits with foam in them.
Old knob and tube also can be an issue.
 
Not the same but related. I went to my plumbing code update a couple of months ago. They talked about spray foam if it is installed in a thick layer (they recommend installing it in multiple layers) it has generated enough heat to damage PVC and CPVC glued joints in pipes hot enough to cause leakage. The piping was pressure tested at rough in and passed. Then the house was insulated causing pipe leaks.

I Imagine the same heat can cause wire damage. They said if the insulation was installed in layers there is no issues.

I realize this is an installation issue separate from what the op is talking about
 
Eddie702 said:
They talked about spray foam if it is installed in a thick layer (they recommend installing it in multiple layers) it has generated enough heat to damage PVC and CPVC glued joints in pipes hot enough to cause leakage.
Click to expand...
What is the temperature of the foam when it is applied?
 
Our fire sprinkler co will not allow spray foam to contact the plastic pipe . needs to be covered with pipe insulation or similar
 
You’re suppose to spray it in a thin layers untile it foams up and is hard to touch then spray another layer. Did nothing to my ent in the wall.
If someone spraying one thick layer there lazy and don’t know how to apply it.
 
infinity said:
What is the temperature of the foam when it is applied?
Click to expand...
I have a UL contact that is trying to contact ULC (Canadian UL) over this 1998 report.
He suggested contacting the Romex manufacturer. I tried contacting Cerrowire, but you have to have a business email.
My UL contact said they should have a temperature study. As moderator do you have a business email that you could contact them with?
Also I found it interesting that under full load the high temperature was reached in 4 hours even though the test was run for 24 hours.
Noted also was that the newer foams were more dense than the one tested.
I have a neighbor that had spray foam installed in a 20+ year home. She has electrical problems now. The house has never been remodeled.
She has not involved me yet, but trying to rule out the spray foam, but as I look into this spray foam raises questions.
 
AC\DC said:
Insulate test the wires. It would “ melt” insulation nothing to the copper
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I was thinking, before the insulation failed, the temperature of the wire would cause the junction points fail.
Especially wire nuts. Being that the wire is rated 90c and terminals are rated at 60c. Insulation testing is certainly in the realm of testing for electrical failure.
 
Well junction points should be accessible to determine that.
My point was buried wire in the wall.
My wall were sprayed 8” thick that skinny emt I ran pulled fine and my nmb in walls is fine.
I know they mix the chemical on site. Maybe you can run then hot if you add to much of one.
On another not been looking to start a spay foam company lol
 
Your right, if they have not buried the JB's in foam.
The mixture of the chemicals on site could cause the temperature of the foam to go above 325F or cause the heat to last longer.
 
Rjryan said:
I have a UL contact that is trying to contact ULC (Canadian UL) over this 1998 report.
He suggested contacting the Romex manufacturer. I tried contacting Cerrowire, but you have to have a business email.
My UL contact said they should have a temperature study. As moderator do you have a business email that you could contact them with?
Also I found it interesting that under full load the high temperature was reached in 4 hours even though the test was run for 24 hours.
Noted also was that the newer foams were more dense than the one tested.
I have a neighbor that had spray foam installed in a 20+ year home. She has electrical problems now. The house has never been remodeled.
She has not involved me yet, but trying to rule out the spray foam, but as I look into this spray foam raises questions.
Click to expand...
My contact at UL said their wire and cable engineer said she know of no study they have done with nm cable in spray foam, but the manufacturer should have done a study. Canadian ULC has not gotten back with him yet. The best hope for a definitive answer is with a manufacturer.
 
infinity said:
What is the temperature of the foam when it is applied?
Click to expand...
I don't know but the instructor said the house in question had PVC and CPVC pipe (which is rated higher than PVC temp wise) and that the pie had previously been pressure tested to pass inspection and that after the spray foam it had loosened glued joints
 
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