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Attic insulation question

1057 Views 9 Replies 6 Participants Last post by  Preston5646

I have a 2000 ft ranch style home in the San Fernando Valley area of Los Angeles. The house was built in 1965 (comp shingle roof) and I purchased it in 2001. The pieces of insulation were installed under the roof. I do not know if any of the previous owners ever replaced it. Several pieces are hanging down now. There is some plywood down on the floor and I store suitcases there, but they can be removed.

What is the most cost effective approach with the best ROI? I will need to get bids from companies that specializes in Attic Insulation. I run the A/C during the hottest months (mostly mid late July through the end of August) and the heat in the winter depending on how cold it is, but obviously, our temperature is relatively mild compared to much of the country, except for Florida. I don't intend to have the attic finished or use it, but if it's replaced, the old insulation will need to be removed.

Does anyone know of a rough ballpark estimate based on the size of my home that the various options may cost? If the bids turn out to be completely unaffordable, are there other options and if I do nothing, is this the kind of thing that could be a deal breaker when it's time to sell? I plan to retire elsewhere, perhaps as soon as 5-8 years. The neighborhood is very desirable and my house is in good condition.

Also, what kind of questions should I be asking insulation companies? I'm trying to avoid surprises midway through the project.

I truly appreciate everyone's input. :smile:

Thanks in advance,
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The underside of the roof in not the best place to insulate.

A few things that should be done.

Air sealing every crack hole and pipe that comes into the attic from the house.

High and low vents to allow air to flow thru from the soffets to the peak and out.

Air shuts near the soffet to allow air passed the insulation.

Attic access door that is weather stripped and tight.
Then you would be ready for insulation.

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Thank you for your quick response. I really appreciate your insight and recommendations.
So your insulation is under the sloped roof, not on the attic floor?

You do mean "insulation", not "radiant barrier" under your roof right now, right ?

I can't think of the logic behind that unless previous owner was planning to use that space, and condition the air.

Is there a flooring in your attic ?

Is there any ventilation in your attic ?
Yes, it's definitely insulation. If my back wasn't out, I'd grab the ladder and include photos. I imagine that the original intent was to use the attic since it's quite large. There is some flooring and that's where I store suitcases, other than that all beams. There are no fans up there, if that's what you're asking. Thanks for your response.
There are no fans up there, if that's what you're asking.
No, not exactly what I was asking. More commonly, the attic floor is insulated, and then there are passive vents in the soffits, for air to enter, and a ridge vent or other at the top of the roof, for air to exit. Then, the attic is considered unconditioned space. If you have no airflow up there, I would be concerned about possible mold. But I suppose you are in a pretty dry climate, so maybe its not an issue.

Its worth the trouble to get an reputable insulation contractor to give a recommendation and quote. But to answer your original question, I can't see how the cost of adding insulation is going to be recovered if you are selling in 5-8 years. More people will be interested if you have granite countertops than how much insulation you have.
It's very dry here, so mold isn't an issue, but you're right. The ROI is not going to happen for something that's mostly invisible. I'll get a few quotes and figure out what's best. I'm also going to get a quote to have the existing insulation tacked back up. Thanks so much!
Can you clarify something? Is the attic "sealed" or not? Are there places for outside air to freely enter and leave the attic? This is important as to where the "thermal boundry" is. Insulation could be installed on the floor OR on the bottom of the roof based on this info? IF there is air going through the attic AND the insulation is on the bottom of the roof, then the insulation is basically worthless. It would be like holding a jacket OVER your head.
I would forget about the existing insulation and seal the floor of the attic space wherever there are penetrations of any kind and then install baffles to insure that the vents are not blocked and blow in 10 inches of insulation. Baffles are cheap and the trick with the blown in insulation is that depending on how the machine is set and the relative humidity when it is blown into the attic the same number of bags can produce different heights of insulation in the attic. Best to have the quote specify how many bags of insulation are going to be used. Important to have a good seal and insulation where you enter the attic from inside the house.
Blown in fiberglass will likely be the way to go. Had this done recently, added R-30 and have noticed a difference in cold/heat retention and energy bills. I would also recommend an attic door tent as well.
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