Wet insulation question.
 

We have a leak in the roof, and the repair will be quick and easy.

But, the insulation under that leak is going to be wet, and it was a bear to get up there. The idea of bagging it and removing it and replacing it is a fairly grim one, seeing as we are both 20 years older!!!!!!

Um,... do we HAVE to remove it? Will we be ruining things if we leave it in? Does insulation even dry out once it has gotten wet?

Could you direct a fan over the wet insulation?

It will make a difference to the kind of insulation you have. I have no doubt whatever you have will EVENTUALLY dry out, but will it still have much insulating value? Cellulose will probably form a nice soggy thin layer of mush that will have little R value even after dry. Let it dry and then add again would be the route I'd probably choose if that were the kind.

Depending on just how wet it is and what it rests against might make for a better decision. Soggy to the point of collapsing a sheetrock ceiling or have mold form on the back of it? Probably no mold as the insulation, if cellulose, may have inhibitors.

How wet, and what type? If it's soaked and staining the ceiling, it needs to be removed. If it's damp and blown fiberglass, it may dry out with no issue. Tell us more? I would be real hesitant to leave any wet cellulose in an attic. It will mat down and get mold real fast.

It was fiberglass batting, and I think it was 4" thick. And, yes, the ceiling was wet.

4" of fiberglass is far too little for current standards, it is probably R13 and you need at least R 30 to R 38. Hate to say it, but it need to be removed, the sheetrock needs to dry and it need to be properly insulated. You will have mold otherwise and you are spend a lot of money heating a place that is sorely lacking in insulation anyway. Think of the bright side, now it will be done correctly, and you will see a big drop in heat bills. If you go that far, before you install new insulation, head on up top with a few cans of spray foam and seal everything that you possible can. Top plates of walls, holes for wiring, build foam beehives over electrical boxes ( not recessed lights, they may not be rated for that) and plumbing pipes where they come up through the ceiling. Less than $20 in spray foam can make a HUGE difference in heating costs and comfort.

Yep, they gotta come out.
Wet fiberglass that dries out is useless. Especially that old.
The water compresses the air gaps in the fiberglass. Without the air gaps, no R value.
Roxul is the only batting type insulation that can get soaking wet and not be ruined. (Mineral wool)
Sorry! Sucks to be you. :(

mold on the sheetrock. replace that too

Why, did the squirt bottle of bleach disappear? There are lots of effective ways of dealing with minor amounts of mold. If the rock is solid and showing little to no evidence of serious mold, treat it and let it dry.

for one the bleach is not that effective at mold removal or i should say, the method of applying it with a squirt bottle....and is not approved of in some places. some areas you must bring in a professional to do his thing which involves drilling holes in numerous places surrounding the area and then he inserts a jet to pump in a mold solution. this solution will also peel and damage the paint in that area. then you must scrape off peeling paint and skim coat the area....repaint.

another thing, we dont know how much damage was done. it was not mentioned. as i recommended before, on another thread, its better to over kill than to underkill. esp. when it comes to water damage and potentiol mold growth.

just the way i do things. thats all.

im sure you know this already but some dont know, that mold feeds off paper. paper that makes up sheetrock. thats why they now make a mold resistant sheetrock. and its best not to use wall paper in heavy moisture areas. ie. bathrooms and even in certain parts of the world where its extremely high humidity.

If the insulation is removed for a visual inspection, the mold, or lack of it, should be quite visible. Personally, I have had excellent results with bleach, but there are many fairly inexpensive product that do the job. As for calling a remediation co. Great idea if you want to turn a $50 job into a $5,000 one. No need to go killing flies with a shotgun here, and few of us have the budget for it anyway.

i do have a question...in installing recessed lights...do you know a proper way of insulating around them? ive always cleared the insulation away from them b/c of heat issues. but is there a way to safely insulate them?

depends on how long the water damage has been there. as to whether the mold is showing up, and your right, the removal will be costly. $5 bills is a slight exaggeration, but figure on a couple hundered at least. and it depends on the job, whos around, and what they say if they know about the damage. some people are fanatical. its best to figure on worse case scenario. so thats why i say pull the rock in that area. its easier and cheaper than going the other route.

Yes, there are two types of recessed fixtures. one is listed IC Rated which stands for insulation contact rated. The other may, or may not, say to leave a specified gap between the housing and the insulation. This info. is often on a label inside the fixture, or stamped on the housing. All modern recessed lights have thermal overloads in the housing. It is a small plastic device with wires attached, and it is located in the housing above the reflector. It will shut off the light when it gets too hot. It will also cycle and turn back on as it cools. That said, if you are in doubt as to it being acceptable to insulate tight to a fixture, don't take a chance. I used to use a lot more of them in my new homes, but I have cut down. They are notorious for leaking air and being difficult to insulate around. In tighter new houses they are sometimes responsible for causing a ring of mold on the sheetrock around the reflector. This is caused by the heat loss, and the fact that it can be much cooler surroundiing the light and it causes condensation.

TY for the info. ive seen this ring of mold before. now i know why. makes sense.

Hi,
I'm sure this is not an approved approach, but its what I do.

Replace all the bulbs in the recessed fittings with CFL or LED lights. This reduces the power and heat produced by 75%.
Seal all the air leaks in the can with aluminum tape.
Then I insulate right over them.
You have to make your own judgment about whether this is safe.


If you want a more code approved approach, you can replace the cans with ones approved for direct contact with insulation -- there are lots of these and they are not that expensive. Once you have done this, you can insulate right over them.

Gary

gary, this alum. tape you speak of, is it the same stuff hvac installers use on their duct work?

The stuff I used is Nashua 324A, and I believe that it is sold for HVAC ducts -- I got it at Home Depot.

I did check this morning on one of the can lights to see how the tape was doing, and it looks fine -- this is after 3 or 4 years.

Gary

cool. thanks for the info.

Sorry, but I have to advise that this isn't a great idea. One of the big issues that allowed for the "upgrading" of fixtures in the last few decades was the specifying of 90C. temperature rated wire. Old wire was either unrated or 60C. It may seem like a silly bit of nerdy academics, but (and there always is a but), it is quite legitimate and important. The issues is that the temperature of the fixture and the attached junction box is MUCH higher than in the old days of recessed lights that leaked air, and had no insulation anywhere near them. Wire that isn't capable of handling the heat simply fails. the copper will be just fine, the insulation however gets brittle and falls off. I was shocked to find a ten year old bathroom fan/light recently where the wires attached to the lampholder had no insulation for the first inch, or so. It had heat degraded, and crumbled off. The issue is that I, (yep, I'm the idiot in this story) had used 100 watt lamps in a fixture that clearly said "60 watt max". The other issue is that if, and it's only a slight chance, you have a fire with a fixture that you modified and insulated, you may be in deep poop. Insurance companies look for reasons to not pay. If the fire investigator hands them a fixture that was obviously modified, and the source of the fire, it's game over. Current regs. call for adding a remote junction box and transitioning over to new style romex when adding fixtures to an existing circuit in an older home. I have had inspectors tell me that it's one thing they strictly enforce, as it is a fire safety issue.

When I checked the can light yesterday with the CFL still on, I could easily put my hand in direct contact with anything in the fixture, including the light, the light ballast at its base, and any part of the can fixture. So, I think the temperatures are probably low enough to not bother any kind of wire -- but, people have to make up their own mind on this.

I think that cutting the heat produced by the bulb by a factor of 4 by using a CFL bulb is the key.

Gary