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Insulation on Cape Cod styled house

I have a 1926 cape code style home in Portland Oregon (DOE Climate Zone 4C). It has lath and plaster walls but also some draft, uneven hvac flow and an upstairs that is fridged in the winter and hot in the summer.

Through my own investigation and a few contractors that have come out with IR guns here is what I know to be the situation.

1. We have conditioned knee walls, insulated with r11 fiberglass batting along the roof. Much of the batting is coming out of the cavities and is dirty and appears wind washed.

2. We have ~3ft of sloped cathedral ceilings, most bays are insulated using the batting, some bays are completely empty per IR gun. The rafters are 2×4 and so there isn’t a lot of space in there. There are no soffit vents and there for no vents heading to the attic. 

3. The attac has 3 inches of cellulose probably original or super old. There is decent space to move around to do some work up there. Two large gable vents for ventilation.

I would prefer to use green and health concious materials so I would prefer to not use fiberglass or spray foam (unless there is a less health risk option I am not aware of).

Any recomendations on how to insulate this space?

Thanks for any help. 

Re: Insulation on Cape Cod styled house


Green Insulation Options:


Sheep's Wool



Rigid Polystyrene



Technically speaking, home insulation is green by its very nature because it saves energy. Then why is "green" insulation greener? For some people, it's green when it contains a high percentage of recycled materials; for others, it's when it doesn't contain harmful substances that can cause health problems. Still, others consider insulation green when it's made of natural materials.


Whatever your definition of green, the best way to quantify how well insulation works is by its R-value, which measures its resistance to heat flow and ranges between less than R-1 and R-60. The more the material restricts the flow of heat, the higher its R-value. 


Generally, the higher the R-value, though, the more it costs. Homes should be insulated with enough material to achieve an R-value between R-30 and R-60. That means if the type of insulation you choose has an R-value between R-3 and R-4 per inch, you'd need to have at least 10 inches of the material to achieve an R-value of R-30.


Re: Insulation on Cape Cod styled house

I have a similar problem... its an old 1.5 story house. the upstairs bedrooms have sloped ceilings and I think zero insulation. How do I insulate?

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