# attic insulation



## Perry525 (Jan 10, 2010)

Do I understand that you have condensation on the ceiling of your bathroom?
If you do, it is because the ceiling is cold and you need to improve the insulation between the joists and below the joists.
The best way to deal with this is to fit a closed cell insulation like polystyrene/blueboard/Styrofoam between the joists. Polystyrene is waterproof and wind proof.
This will help the ceiling to keep warm, it is best to pull the ceiling down and to also fit sheets of polystyrene below the joists, three inch thick polystyrene fitted below the joists will stop your heat from escaping and will also stop ghost lines forming, where you can see the position of the joists because that part of the ceiling is colder than the rest.
The problem with most exhaust fans is that they have to pull air from somewhere to shoot it outside, this causes cold drafts and costs you a lot of money with your expensive warm air moving outside and cold air coming in. A better solution is an exhaust fan fitted with a heat exchanger, this replaces the warm air, with warm air as the incoming air is warmed by the outgoing air saving as much as 90% of your heat and of course there are no drafts.


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## Windows on Wash (Aug 30, 2011)

If you have floored storage, you don't have enough insulation.

If you have moisture, you don't have enough ventilation and/or you are not getting the moisture out of the home properly.

You should re-examine the whole attic and get it corrected asap. A false floor to allow for more insulation depth combined with added insulation and air sealing will do wonders.

Make sure the venting is proper with proper baffles, soffits/gables/ridgevents/etc, and get the humidity out of the home and don't dump it into the attic. Bath fans are a must in this case.


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## Canucker (May 5, 2011)

Is it dripping in the attic or the bathroom ceiling?


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## Barry J (Nov 21, 2008)

The dripping is on the ceiling of the bathroom when we take showers . It's right over to tub area and happens only in cold weather , despite already having an exhaust fan
I believe it is condensation from the hot air from the showers hitting the ceiling which is cool from not enough insulation in attic


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## Perry525 (Jan 10, 2010)

That is correct!


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## Windows on Wash (Aug 30, 2011)

False floor + air sealing + more insulation.


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## Barry J (Nov 21, 2008)

What do you mean by a false floor??
Do I have to pull up the floor that is already there?? Obviously probably do


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## mnp13 (Jan 16, 2007)

A false floor is a raised floor so that there is enough clearance over your joists for the proper amount of insulation.


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## Windows on Wash (Aug 30, 2011)

+1

Kind of like this....


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## Barry J (Nov 21, 2008)

I don't have that much room in my attic , I have to crawl around on my hands and knees. And I still hit my head on the roof.

But I'm gonna lay down some insulation going perpendicular to the exposed rafters on the edges. What type of batts should I use?? Unfaced , faced???


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## Barry J (Nov 21, 2008)

I want to lay down additional insulation on the edges of my attic, I will use the styrofoam vents in between the roof rafters, but what "R" value to use and unfaced or faced,
Thanks
Barry


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## mnp13 (Jan 16, 2007)

The higher R value the better. If you are adding to pre-existing insulation I believe you need unfaced because you will get condensation between the two layers. If you can pull up the attic floor, air seal everything, then put down foam and/or cellulose you'll probably be in better shape. But if your joists are only 2x4 or 2x6 you don't really have enough room for high R-value. Ideally, you should put another run of joists to raise your floor a few inches for more insulation.

Is your bathroom fan vented directly out of the attic, or just up to an attic vent?


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## Barry J (Nov 21, 2008)

Can't raise the floor anymore, I have a very shallow pitch and have to crawl on hands and knees as it is.
The bathroom fan is vented out the roof of the attic


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## Windows on Wash (Aug 30, 2011)

Barry J said:


> I want to lay down additional insulation on the edges of my attic, I will use the styrofoam vents in between the roof rafters, but what "R" value to use and unfaced or faced,
> Thanks
> Barry


Are you removing what is between the joists already of just putting down extra?

I air seal what you can first, blow cellulose.

If you put down batts, they should be unfaced if you are going over top.


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## Barry J (Nov 21, 2008)

I will be adding to what is already there on the edges, and running it perpendicular to the rafters


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## Gary in WA (Mar 11, 2009)

I'd pull the f.g. to use farther back from the low-slope. Here I would use rigid foam board (after air sealing), for 2' or more. Stack them up, staggering the joints against air pathways. http://bct.eco.umass.edu/publications/by-title/reroofing-and-residing-to-save-energy/

Problem is the required R-value in the limited space, as you well know, hitting your head often. I don't envy you.........

Gary


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## Windows on Wash (Aug 30, 2011)

+1

Air loss and low R-Value at the eaves are the two biggest issues that contribute to ice damns and snow melt.


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