Feeling dupped and trying to recover

[jps3d]

Hey guys,

I have a raised ranch and I live in NJ. The home was built around 1960 and we have spent the last ten years making improvements on the home. We recently made the decision to spray foam our attic as per the advice of a local contractor. Before the work was started, the attic was a traditional attic, had old fiberglass insulation and that was it. He pitched the idea of the area being a "conditioned space." We have a number of concerns, since the work has been completed, the house seems much colder than it ever was. All of the old fiberglass insulation was removed due to it's age and condition. When the spray foam was installed, the ventilation fan was covered over so the entire space was unventilated. My question is this, how can I warm up the house with the situation that I'm currently in? I'm thinking of opening the previous ventilation windows on either side of the space and installing bat insulation back down on the floor. What kind should I use? I want to use the "safest" kind because my daughter has significant health issues so I have to be very careful. Thanks so much for the advice and insight in advance.

Chilly in NJ

 

[user 4883]

Just want to make sure I'm following correctly.
All insulation was removed and replaced with spray foam. The attic gable vents were sealed up and now it is colder in the home than before?

 

[jps3d]

Yeah, the spray foam was applied to the interior of the roof and all ventilation has been sealed up. As far as I'm understanding this, I have essentially screwed myself by expanding the interior space which is now being heated and cooled. Prior to the spray foam, the attic was a separate space that which experience typical drastic temp shifts in the summer and fall.

 

[user 4883]

Yeah, the spray foam was applied to the interior of the roof and all ventilation has been sealed up. As far as I'm understanding this, I have essentially screwed myself by expanding the interior space which is now being heated and cooled. Prior to the spray foam, the attic was a separate space that which experience typical drastic temp shifts in the summer and fall.

So now no insulation between the ceiling joists in the attic?
If so, yea; your going to want to reinstall some insulation R38 - R60.
I'd recommend something easy to handle/install (nothing blown-in).
Cellulose batts or fiberglass are pretty much your options.
Open up your soffit vents and ridge or gable vents.

 

[jps3d]

Right, there's no insulation there now. I was thinking of using Rockwool, looks really safe and effective. I don't have soffit vents but I do have gable vents, just have to unbury them from the spray foam.

 

[user 4883]

Right, there's no insulation there now. I was thinking of using Rockwool, looks really safe and effective. I don't have soffit vents but I do have gable vents, just have to unbury them from the spray foam.

I don't really see what was gained by spray foaming the underside of the roof sheathing. Should have spray foamed the ceiling joists. If the intent was to use this as living space, then the space needs to be ducted for heating and cooling.

 

[jps3d]

You're 100% correct. It was my mistake to take the advice of someone (the contractor) that was looking to increase his profit rather than doing what was asked and made the most sense. This is not the only issue that I have had with him. Live and learn I guess. Now, I'm just looking to remedy or at least improve the situation that I find myself in.

 

[oldognewtrick]

I've been to many houses over the years that have been spray foamed, it's always done on the underneath side of the roof deck. They should have installed ducting into the attic to condition the space. There's a good chance your HVAC unit is undersized to account for the additional demand if ducting was installed.

 

[jps3d]

The idea of conditioning the attic space was never my intent and it's still not. It will be purely used for storage.

 

[oldognewtrick]

https://www.energyvanguard.com/blog/3-reasons-to-remove-attic-floor-insulation-in-a-spray-foam-attic

 

[ctviggen]

One problem I have with this type of insulation (insulating the roof deck), is this exact problem. Sure, the attic is now "conditioned" space, which IS a possible benefit if you have heating and cooling there. However, now you have a huge space to heat/cool. How does that work?

The other main problem I see is that most contractors just want to foam between the rafters. But wood is only an R value of 1 per inch, about. Say you have 10 inch rafters. You have an R value of 10 there. If these are space 16 inches on center and are 1.5 inches wide, that's almost 10% of the insulation with an R value of 10. Let's say you get an R value of 40 (and remember -- a lot of the R values quoted are initial and don't count degradation over time) for the spray foam (and this value depends on thickness, manufacturer, and type of foam used), then you really have an R value of about 37. This is even worse if they only put in a few inches of (closed cell) spray foam and leave a lot of the rafters uncovered, as this provides a lot of surface area to "radiate" cold or heat.