What a difference a little foam makes

[CTwith3]

Getting ambitious here. Went down to my uninsulated basement (block walls) and pulled all the insulation out of the floor joists above. I had my son vacuum around the rim and sprayed the can foam where the block meets the sill and everywhere there are joints. There were plenty of holes from the basement ceiling into the walls for electric, telephone, cable, pipes, etc. and sealed those holes up well. Then I had my son run foam along both sides of all the edges of where the joists meet the sub-floor. Today I went down to the basement and it definitely feels much warmer. So far I am into about nine cans of foam. Insulation is going gack up over the next few days.
My house is a split so I have perpendicular adjoined roofs. Years ago, when I was younger, braver, and healthier, I beefed up the insulation in the attic above the roof of the upper floor where the bedrooms are, but at that time (2002) I hadn't heard of air sealing, plus the pitch on my roof is so shallow that at it's highest point I think there is only 4' of ead space. Now I know I need to get up there and rollback the fiberglass to find and fill the leaks.
The attic over my living room and kichen is only made accessible by removing the vanity in the upstairs bathroom wall. I removed it once and there is only about 3" of filthy insulation that gave me an asthma attack. I'm tninking of removing the vanity and putting my big round HEPA air filter in there for a few hours and then going in with a good face mask. Call me crazy but I was thinking I should pul lout the filthy thin insulation, fill the air gaps with foam, and roll in new fiberglass between the joints, and then lay another layer of unfaced batts across the tops of the new batts I put in between the joists. I was thinking of renting a blower and finishing off that way, but the guys at Homer's tell me to go with batts. Between the living room and kitchen I have ten IC air-tite recessed lighting cans. I tried to get a pro in to do the job for the past few years but they don't want the job, or they give me ridiculous prices- because they don't want the job.
I've been watching lots of videos on YouTube to try and get as much info as possible.
Sound good?

 

[GENECOP]

Just because the insulation is filthy doesn't mean it's not working....I don't think it's worth the effort to remove all the old in order to do the spray foam thing....look from below, how many penetrations are you really going to seal...adding some new batts on top, that's a good plan.....It's not that complicated, depending on the size of the joists, add, filling up the cavity, if the space has no floor in it, go thicker, or stay below top, then add a layer of foil faced rigid, foil facing living space...if you go this route, use unfaced batts....leave room around Highhats so you dont trip them off...good luck..

 

[CTwith3]

No floor in attic.
Wll have to move around all insulation to air seal thoroughly.
All high-hats have LED bulbs in them so they seem to give off little heat. The high-hats are IC and I added the air-tite baffles. The cans were cold before putting in the baffles. I checked the baffles the next day, and they are not cold!

 

[woodgeek]

Sounds reasonable...my 2 cents...

$20 will get you a valved mask with 2" filter cartridges that are rated for working with toxics. That and goggles should be a good start for you PPE, skip the paper masks. Depending on your asthma....consider carefully.

I would also keep the HEPA out of there...don't want to contaminate it...filters can re-release what they catch.

If you work in cold weather, I suspect the conditioned air will flood into the attic, flushing the bad stuff out the vents (?), keeping you warmer, and keeping the bad stuff out of the house. If you work in warm weather....all these good things get reversed..no bueno.

Removing the old stuff is usually a waste of time/effort, but a matter of personal taste. You can just push it around to airseal, and then just cover it over with more insulation when you are done. If it is a large area, it might be cheap to have a cellulose guy do a quick blow over vs your cost for FG.

 

[DickRussell]

Be careful with what you do on air sealing and insulating can lights. The current (March 2015) issue of Fine Homebuilding magazine, page 56 has an article titled "Air-sealing Can Lights Safely." The caption in the index says "Common air-sealing enclosures can lead to melted foam, shorted wiring, and even fire." The article talks about the different types of fixtures, common ways of addressing them, the different types of light bulbs that can be used, and the measured temperatures that can result. It also talks about wiring type (NM vs NM-B). Their bottom line conclusion is that the safest way to go is to install an LED can light conversion kit. The one they tested draws 13 watts and produced a temperature of only 123 F inside. Compare that with the 245 and 246 inside two of the can cover options and using a 75 watt standard bulb. The melting point of polystyrene was given as 167 F. Even a 22 watt LED lamp tested inside a polyiso cover generated 144 F inside, not high enough to trip the high temperature switch but over the 140 F that older NM cable is good for. NM-B cable is good to 194 F, according to the article.

 

[semipro]

skip the paper masks

I couldn't agree more.
I've dealt with so much fiberglass, dust, mouse droppings, etc. working on our house that I finally invested in one of these. http://www.rockler.com/power-air-respirator
I've never been able to find eye protection compatible with a respirator and you need both when you're breaking rock and such. The constant airflow of a powered respirator keeps my goggles/glasses from fogging.

 

[Dune]

I would consider blown in behind the the vanity. Like R-60.

 

[CTwith3]

Thanks for all the advice, I have a respirator mask goid for sanding with the the filters on each side of yhe mask, are thise good? I hear you about the HEPA filter, I bought a new filter for it for after this job is done, but I can't get the filter through the opening anyway.
I pulled out the vanity and here is what I found:
Black paper faced yellow insulation about 1" thick. On top of that was someold OC R-11 foil faced fiberglass- faced side down. On top of that is a filthy mess- tons of dirt, pieces of shingles, along with the grit/grain you find on shingles. Fiberglass is sticking up in lots of palces, plus I also saw a couple of acorns.
Last spring I had to have the facia replaced because the baords were rotted from damage caused by Hurricane sandy's winds and the gutters loosened up and beating on them. I went a few feet in with a drop light and didn't see vents for the eaves- it looks like the insulation in there is pushed all the way to the ends not leaving room for proper venting.

 

[sesmith]

Personally, I would just blow a layer of cellulose over what you have up there to beef up your insulation level. I hate working with fiberglass and wouldn't think of disturbing old fiberglass insulation, unless I really had to. The cellulose will seal air flow much better than fiberglass. Rodents don't love it like they do fiberglass, and it takes hardly any time to blow in a layer of cellulose using one of the blowers they have in the big box stores. Anyhow, that's what I did with our place when I added insulation overhead, and left the fiberglass in place. If you're really ambitious, you could peel it back and spot seal any penetrations and wall areas with foam first.

 

[laynes69]

If you're really ambitious, you could peel it back and spot seal any penetrations and wall areas with foam first.

Can't agree more! We had some half ass contractor come in back in '93 when my parents owned our home. They loosely stuffed in pieces of insulation in open cavities at the attic floor and blew a few inches of cellulose on top. It looked like a solid blanet of insulation, until I started pulling the cellulose away. In total, 32 open cavities leading from the living space below to the attic robbing energy. The equivalent of a 6' diameter hole. It made a huge difference, even with a few inches of insulation. The next year, we blew 52 bales of cellulose, and since it settled now to 8-10 inches, I'm going to blow in more. It took a while to investigate, and was an extremely dirty job, but well worth it.

 

[CTwith3]

So, peel back what's there air seal with foam on the tops of the wall joins and spots where holes for running electric through the wall may be, look for empty cavities as I back out and rearrange current insulation to cover those empty areas if they exist, crawl back in half way or so with the hose from a cellulose blower, and fill?
Ignore the fact that the second layer of insulation has a foil face and it is facing down? Don't be concerned about moisture? What about the fact that the insulation goes edge to edge and it could be blocking air flow into the attic as is designed?

 

[ihookem]

You used 9 cans of foam? The little $3 cans? Very cheap insulation huh?

 

[STIHLY DAN]

That sounds like a terrible job. Some things are worth paying for.

 

[CTwith3]

You used 9 cans of foam? The little $3 cans? Very cheap insulation huh?

Yup, for sealing 600 sq feet, I'd say it's a good deal.

 

[sesmith]

So, peel back what's there air seal with foam on the tops of the wall joins and spots where holes for running electric through the wall may be, look for empty cavities as I back out and rearrange current insulation to cover those empty areas if they exist, crawl back in half way or so with the hose from a cellulose blower, and fill?
Ignore the fact that the second layer of insulation has a foil face and it is facing down? Don't be concerned about moisture? What about the fact that the insulation goes edge to edge and it could be blocking air flow into the attic as is designed?

Assuming that your existing fiberglass was put in more or less correctly, adding to it shouldn't be an issue. The kraft facer should be down toward the warm surface. Obviously, you have to be careful not to block existing soffit vents. Using one of the cellulose blowers is a pretty easy job, though not quite as easy as sitting halfway back and letting it rip. It will take a second person to break up the insulation bales and feed the hopper as you blow...a couple of cell phones helpful to communicate back and forth. If you have reservations doing it yourself, hiring it out and just writing the check has some advantages.

 

[CTwith3]

Problem is that it turns out the previous owner had someone add insulation over the original 2" insulation that also has the kraft facing down- 2 layers of insulation both faced.

 

[woodgeek]

Problem is that it turns out the previous owner had someone add insulation over the original 2" insulation that also has the kraft facing down- 2 layers of insulation both faced.

If airsealed well below, and vented above, the ancient vapor barriers will make no difference at all.

 

[valuman]

Assuming that your existing fiberglass was put in more or less correctly, adding to it shouldn't be an issue. The kraft facer should be down toward the warm surface.

While I don't think it'll matter with complete foam air sealing, faced insulation is not designed for use in an attic or floor space; it's for walls only. The facing is a vapor barrier and the moisture should be allowed to pass through in the ceilings/floors.

 

[DBoon]

The facing is a vapor barrier and the moisture should be allowed to pass through in the ceilings/floors.

True, but if the faced insulation is just laid down in the attic, the vapor barrier is highly incomplete and compromised, so this will be a non-issue. Still, additionally fiberglass added should be unfaced.

 

[sesmith]

Also, kraft backing is a class 2 vapor retarder, not an actual vapor barrier to the point that polyethylene is, so I doubt that the extra layer is really an issue, especially since it is just laid in place (unless there's an excessive amount of moisture in the building).

 

[john193]

I recently insulated the rim joists in my basement as well. I could not believe the amount of cold air that was rushing through there. I cut r-6 foam board to size, friction fit the piece into the joist and then air sealed it by putting a 'frame' of expanding foam around it. There were a few areas where I just couldn't get to so I did what I can. Overall I noticed the basement has felt less drafty and chilly. Now the only cold i feel in there is from my heat pump water heater.

 

[BIGDADDY]

The one thing that ruins fiberglass insulation is moisture. If it gets wet it will lower its value, R value that is.

 

[dougstove]

I had some old can lights perforating my ceiling, and rather than sealing them up, I just removed them and sealed off the holes.

 

[CTwith3]

Can to lip sealed, air-tite IC with air-tite l
baffles for the LEDs, so cans not the concern- air dealing and insulation is.