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rololow 04-07-2014 10:49 PM

Cellulose Insulation Questions
Hi, I'm new to the forum and home owning. I live in the Seattle area and want to add insulation into my house. I'm a DIY. And prefer to try to save money where I can and pay the contractors for the hard stuff. My attic currently has a form of cellulose in it that is very uneven through out. The estimate I received said that my insulation is anywhere from an R-11 to R-19 and I would like to bring it up to a R-39.

I've done a lot of research about installing blown in cellulose. Per the articles and instructions, they said to install baffles to help with the air flow. I already did this. Pretty much everything I've read says that I should be able to see light come up through the baffles. The one's I purchased were about 48 inches long. I can't see any light through them. I even had someone hold a flashlight up to the vent outside the house to see and still nothing. I installed the baffles against the eves of the rafters against the wood where the three holed vents are. Did I not properly install them??

Secondly, is there a "limit" to the amount of cellulose insulation someone can blow in? From the calculations I've done for the square footage of my house, I will need to add 30-35 more bags of cellulose to bring my R value up to 39. This seems like a lot. I just want to make sure that I don't add too much insulation and cause my attic to have an airflow/ventilation problem.

Any help is greatly appreciated!

Thank you!

nealtw 04-07-2014 11:13 PM

Welcome to the site.
The baffle should be installed against the roof sheeting to extend just past the extrior wall and the rest of the gap filled with batt insulation which will stop the loose insulation from falling into the soffet area.
I installed the baffles against the eves of the rafters against the wood where the three holed vents are. Did I not properly install them??
I can immagine a few places where you could have wood with three holed vents, can you explain that better?

rololow 04-07-2014 11:30 PM

Lol, I'm sure that would help!

If I remember correctly I have 15 different rafter sections that have bird blocks. I bought plastic black baffles and stapled them to the roof sheeting. Similar to what this gentleman does in this video.

I had to remove the old cardboard baffles, to install the new plastic ones. There was already blown in insulation under the old cardboard baffles. I was able to completely see the bird blocks while installing the baffles, and after install there is no visual of them.

nealtw 04-08-2014 12:06 AM

1 Attachment(s)
In you video it is not clear that the soffet area outside the wall is clear of insulation and his soffet is plugged no air movement is possible.
OK I understand birdblocks, nothing easier here. You should find a way to clear the area of insulation do a partial cut on the baffle so you can bend it down to include a space over the three holes. Then staple into place and back that up with a peice of batt insulation which will stop the loose insulation from plugging everything up.
BTW. Don't forget to raise the sides of the attic access before adding more insulation.

beachguy005 04-08-2014 07:50 AM

Look here for recommended R values. Your zone is up to R60 for an uninsulated and adding up to R38 in an attic with some existing insulation.

I'll also mention you should check with your utility company for any rebate money or other programs.

The other issue you should consider is attic access after you add 18 inches of cellulose. It looks nice and even with great coverage but if you have to go up there to do some work, add a circuit or find some's a nightmare.

I had it done and I wished I had used fiberglas batt insulation.

rololow 04-08-2014 10:37 AM

@Nealtw: Thank you for the picture that was exactly what I was wondering about! Looks like I will be redoing the baffles.

@beachguy005 great link! Thanks!

nealtw 04-08-2014 11:07 AM

BTW, congrats on the first house. For the day you may want to sell the house, you should start a book of pictures, receipts and explanations of repairs that you do.

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