# Wiring an electricians dream house



## 10492 (Jan 4, 2010)

den said:


> They covered over all the soffit and ridge vents and the contractor said moisture is not a problem this way as the air will never reach any wood that is cold??


That post was kinda hard to follow, but this makes no sense.

They filled the soffit and ridge vents with foam?

The roof won't be able to cool itself, and I would think expand until it cracks.

Is this something new?


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## MDShunk (Jan 7, 2007)

I've heard of that insulation method before on ContractorTalk. What I know also is that every spec of moisture generated in the house cannot get out, so a air-to-air heat exchanger is required on the HVAC equipment to keep the place from growing mildew inside. They've basically insulated the house like a big walk-in refrigerator.


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## 10492 (Jan 4, 2010)

MDShunk said:


> I've heard of that insulation method before on ContractorTalk. What I know also is that every spec of moisture generated in the house cannot get out, so a air-to-air heat exchanger is required on the HVAC equipment to keep the place from growing mildew inside. They've basically insulated the house like a big walk-in refrigerator.


 
What would keep the moisture outside, from coming in?

Something else has to be going on in the attic, there has to be some kind of air movement or yeah, it would mold up a storm, not to mention get hot as hell.


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## den (Mar 28, 2009)

Sorry if this was hard to follow. Yes they put fiberglass ins. in the soffit so they could spray foam them solid and foamed the rafter and sheeting solid and foamed in the ridge vents solid. I don't know about an air to air exchanger. Contractor said that the attic area will be within 3 degrees of the rest of the house at all times. The homeowner sheated the roof and then put metal on top of that for roofing. There is no insulation being put on the ceilings from the attic side. I have seen alot of commercial and shop buildings with foam but this was my first house I have seen it done on


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## Speedy Petey (Jan 10, 2007)

I've done a few houses like this and they are awesome!

No hot attics and you will never hit your head on a protruding roofing nail. :thumbsup:


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## Toronto Sparky (Apr 12, 2009)

Wouldn't that make the shingles get a lot hotter and not last as long?


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## kbsparky (Sep 20, 2007)

No, they indicated it was a _metal _roof. No shingles there ...


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## 10492 (Jan 4, 2010)

Now I see, they are foaming between the roof trusses.

I don't see the point though. If the cieling is insulated properly, and the roof is vented properly, why would you need to foam between trusses and vents?


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## Speedy Petey (Jan 10, 2007)

Dnkldorf said:


> I don't see the point though. If the cieling is insulated properly, and the roof is vented properly, why would you need to foam between trusses and vents?


Maybe to prevent a 1,000,000 degree attic between the roof and insulated space.


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## 10492 (Jan 4, 2010)

Speedy Petey said:


> Maybe to prevent a 1,000,000 degree attic between the roof and insulated space.


I would think ventilated soffits with a power vent would be a ton cheaper.


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## Speedy Petey (Jan 10, 2007)

Dnkldorf said:


> I would think ventilated soffits with a power vent would be a ton cheaper.


Certainly, but we have all been in attics with plenty of ventilation that were still over 100 degrees.


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## den (Mar 28, 2009)

The house was really cool when it was hot out and they were just starting to put up sheetrock on the ceilings. The heating contractor was just looking over the job so I don't know about the air exchanger yet. I could see it being nesessary. I thought the metal roof would vent thru its ribs but maybe not. It was just nice being in there working.


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## Shockdoc (Mar 4, 2010)

den said:


> Finished rough in on a new 2 bedroom ranch over basment walk out and it was spray foamed yest for the insulation. They used closed cell and put it on 2" thick so all my wiring is still in the open with a space to the rock if I ever need to get more wire in and they sprayed the roof rafters so the attic is totally exposed with no insulation on the ceilings. It will be at the same temp as the rest of the house. They covered over all the soffit and ridge vents and the contractor said moisture is not a problem this way as the air will never reach any wood that is cold?? He cost 1.34 per square ft. per in. or 2.68 per sq ft which sounded reasonable to me. I liked the idea of no insulation to bother any future work and the attic will be climate controlled with no dust!!


I've only encountered one custom rough with sprayfoam, I encouraged the HO to have use rough it out in ent, we formed custom boxes around the hihats and had him stuff them with fiberglass insulation to keep the jboxes accesible.


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## Old man (Mar 24, 2010)

I have been in 2 houses that used this type of insulation. Its called Isolyene I think. (check the spelling all you english contractors) It has several benifets one of which is that even though it costs more because it is such a great insulator you can use a smaller SEER rating on heat and cooling and in the long run save money at least thats what a GC told me. The entire attic is completely sealed and maintains a near constant temp. Here is my thinking on the shingles if they are used.... they get hot during the day and stay hot well into the evening. As late as 1 or 2am in most attics are hotter than heck. So, even though they are hot during the day,just like all shingles, when the sungoes down they cool quickly thus saving the lifespan of the shingles.

Also, ECs know that SE and SER must use the 60 degree column when SE and SER leaves the main panel and is run to heat, heat pumps, subpanels or anything else in a dwelling if it passes thru the stucture of the house. I have heard the in the 2011 code that issue will be addressed to indicate that one must use the 60 degree column when said wires pass thru insulation. This isolyene was the culprit that made us use the 60 degree column in 2005 or 2008 and everyone, esp. insppectors are just now realizing it.


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## macmikeman (Jan 23, 2007)

In about 30 years there will be tons of lawsuits clogging up the courts and EPA will have a hayday with that product. I probably won't be around to witness this, so you pups remember my prediction for me ok?


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## TOOL_5150 (Aug 27, 2007)

Speedy Petey said:


> Maybe to prevent a 1,000,000 degree attic between the roof and insulated space.


I would pass on any work needed to be done in that attic for sure! :laughing:

~Matt


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## Texas Technician Tony (Dec 17, 2020)

Hopefully the HVAC contractor is up to date with the combustion air requirements needed for that type of dwelling. All gas furnaces require terminating the flue vent outside. I’ve seen standard equipment installed that would create such a negative pressure inside the building that would cause fresh air (furnace combustion air) to be pulled down the water heater flue pipe, chimney, vent hood over the stove. I’ve even seen the negative pressure strong enough to prevent the draft pressure switch from closing. Dwellings such as these must have “all Electric” Heat or Heat pumps OR one the high efficient “2 pipe” gas furnaces which pipes in combustion air from outside the structure, directly to burner compartment of the furnace. A huge benefit of that would be both intake and discharge piping is made with PVC.


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## Southeast Power (Jan 18, 2009)

Is this 10 plus-year-old thread resurrection a record? 
I would like to see all threads retired and closed after one or two years. It that at all possible?


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## Kevin (Feb 14, 2017)

Southeast Power said:


> Is this 10 plus-year-old thread resurrection a record?
> I would like to see all threads retired and closed after one or two years. It that at all possible?


This has been brought up before. Not everyone is for it. For now we're just going to manually lock them.


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