# Sick house syndrome due to spray foam



## Tweed11 (Mar 6, 2012)

I'm a excavator by trade but help my dad build one to three customs a year. We are starting my sister and brother in laws house In about a month and He wants to spay foam everything 3" of closed cell in walls,4" on concrete basement walls, 4" on rim joist, and at least 2" on the top of drywall in attic for moisture barrier. Then put 20" or so of blown in cellulose or fiberglass overthe foam. All this with Anderson 400 windows and thermatru doors and we glue all bottom plates down and Vulcom joints. We live in northern Illinois and my heating and air guy is concerned about this approach because of sick house syndrome and noway for excess moisture to escape. Just want other professional advice or opinions. I don't know if this is in the right forum topic either so sorry.


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## Inner10 (Mar 12, 2009)

Plenty of houses built like that here, but we have to seal everything in 6 mil poly anyways.


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## EricBrancard (Jun 8, 2012)

Ask your HVAC guy why he doesn't recommend an HRV to provide mechanical ventilation.


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## CENTERLINE MV (Jan 9, 2011)

http://zehnderamerica.com


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## jtmorrow (Jan 30, 2014)

Your brother-in-law has the right idea... seal and insulate the house well to fight the ever increasing heating costs, but install a heat recovery ventilator (HRV, as mentioned by Eric) to control the intake of fresh air and rob some heat from outgoing air.


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## Golden view (Feb 16, 2012)

Third on the HRV. It's the modern, better way. Make it as close to balloon-tight as possible, then ventilate.


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## B.D.R. (May 22, 2007)

Try to suck air out of a pop bottle.
That is how your exhaust fans will work with out HRV.
Nothing like sucking exhaust fumes back down your chimney.


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## atvalaska (Jan 14, 2014)

set up/adjust the HRV right ...helllll its a condition of sale in these parts


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## atvalaska (Jan 14, 2014)

"golden view" can see!..... that's what u need to do ....fresh 80's have a roll ...but not in that set up!


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## jaydee (Mar 20, 2014)

the new IRC code change coming up.

I thought I saw something about

mechanical ventilation be a requirement.

continuous r-5 on exterior

r-40 over top plates


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## smalpierre (Jan 19, 2011)

EricBrancard said:


> Ask your HVAC guy why he doesn't recommend an HRV to provide mechanical ventilation.


My stepdad is a mechanical engineer and works on commercial buildings. I remember him saying something about make-up air systems in commercial buildings. Is this what HRV is?


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## NJGC (Apr 5, 2014)

FWIW, given this is my first post.....I built my house very much the same way you describe except I chose to spray foam the underside of the roof rather than the ceiling so the attic is semi - conditioned space. My heating and cooling costs are very low and we have no problems with "sick home". As others have said just make sure you have some sort of mechanical ventilation in place and you should be good to go. Good Luck with the build.


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## flashheatingand (May 3, 2008)

How much is natural gas out east? I thought we all pay about $1.00 per therm. If so, I don't understand why folks aren't "demanding: that their municipalities bring in gas lines.

Oil is too expensive to be the norm anymore (opinion). Personally, I don't like super tight homes. Things get too stuffy. Yeah, I know, that's what hrvs are for. But, thats just another piece of equipment that may or may not get abandoned in a few years.


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## EricBrancard (Jun 8, 2012)

flashheatingand said:


> How much is natural gas out east? I thought we all pay about $1.00 per therm. If so, I don't understand why folks aren't "demanding: that their municipalities bring in gas lines.
> 
> Oil is too expensive to be the norm anymore (opinion). Personally, I don't like super tight homes. Things get too stuffy. Yeah, I know, that's what hrvs are for. But, thats just another piece of equipment that may or may not get abandoned in a few years.


NG lines are never going to reach some of us. Just the way it is. 

As for HRVs, I'd much rather have fresh air brought in through ducting and preheated than rely on air making its way through cracks and crevasses carrying numerous contaminants in on the journey.


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## NJGC (Apr 5, 2014)

Unfortunately Natural gas isn't available in my area. I use propane and it's expensive so I chose to build tight and I'm happy with my decision.


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## flashheatingand (May 3, 2008)

I understand that. But, why aren't folks demanding to have ng? I know, "money, now what's the question ?"

But seriously, we don't have a problem with expending dollars for cell towers, or establishing lines for cable tv. It also seems as though there is always work being performed on our roads. But, shelling out money for a less expensive way to heat homes isn't attainable? It just seems as though with the whole energy conservation thing, we are putting the cart before the horse.

Somehow "you guys" should be figuring out how to bring gas lines in.


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## flashheatingand (May 3, 2008)

EricBrancard said:


> NG lines are never going to reach some of us. Just the way it is.
> 
> As for HRVs, I'd much rather have fresh air brought in through ducting and preheated than rely on air making its way through cracks and crevasses carrying numerous contaminants in on the journey.


I can understand how bringing in gas lines wont happen for some remote areas. But, I don't understand why it won't happen for the heavily populated areas. For the most part, it's the best method of heating.


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## flashheatingand (May 3, 2008)

NJGC said:


> Unfortunately Natural gas isn't available in my area. I use propane and it's expensive so I chose to build tight and I'm happy with my decision.


If your happy, great. Especially since propane is so expensive. I just think bringing in a less expensive source of heating is more beneficial than making sure ones home is super tight.


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## Golden view (Feb 16, 2012)

In Faibanks, Alaska, it's almost all Oil heat (they actually truck NG in but it's a lot more than $1 a therm). Coupled with 14,000 HDD, it gets expensive to heat.

We've been talking about a gas line for years now, but the cost is absurdly high. There is a huge amount of gas 400 miles north at the North Slope oil fields, enough to heat and power Fairbanks and sell extra, but the billions to build the pipeline and the cost to run gas to even half of the 80,000 residents might just be so high the payback period will be never.


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## EricBrancard (Jun 8, 2012)

flashheatingand said:


> I can understand how bringing in gas lines wont happen for some remote areas. But, I don't understand why it won't happen for the heavily populated areas. For the most part, it's the best method of heating.


Where I am I don't think it's ever going to happen. I know of some people in more populated areas who are only a few blocks away from NG and are trying to get it piped over with little success. I would love to be on an NG line.


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