NJ attic insulation

[47WDXPW]

I never really paid attention to this before but I should have. My home attic has a ridge vent and as of now has only 9" of craft backed (facing down) fiberglass insulation. There are plastic air flow partitions nailed up in every bay for air circulation, would blown in cellulose be the most effective and what would be needed. The current insulation just says certainteed on the back without an R value. How would more fiberglass work ? Thanks.

 

[Firebrick43]

Cellulose is the most effective. In cost per R value, in air sealing(at least in your specific situation) and is better in a fire. Also fiberglass has a bad trait of forming convection currents when the temp difference get high

If you have the eaves blocked off and soffit chutes already installed there is nothing more to do than blow it in. Around here if you buy so many bags you get the blower rental for free for so many hours.

Last house I did was my mothers, she and my wife loaded the insulation in the machine and I blew it in. It's best to do it on a cool or cold day as I recommend a respirator(I use a full face) and a tyvek suit with the cuffs taped. As far as how much, most recommend enough to achieve r60. That will be about 10 inches on top of the fiberglass

 

[47WDXPW]

Firebrick thank you, is there anything I should beware of buying the cellulose ? Brand, anything to avoid ?

 

[Firebrick43]

Just make sure it's treated with borates. I think all of it is now. It's what keeps the bugs out and gives it its fire resistance.

O an be careful where you walk! Don't fall through the ceiling.

My mother resisted adding insulation for a couple of years but finally convinced her and blew it in a nov several years ago. It cut her heating bills and cooling nearly in half. Looking back she said the real difference is the comfort levels. Several rooms had cold spot as did one bathroom. She's ticked pink with how even and cozy things are now

 

[yeldogt]

The baffles are technically to keep the roof cold in the winter by allowing cold air to pass along the bottom roof deck.

NJ has a "Clean Energy Program". They provide free home audits -- recommendations and associated rebates and loans. It's an amazing program ... if you hit the saving goals the program provides 4k in direct rebates and 7k for 10y at 0%. How old is your equipment ?

To do the audit they do a blower door test and very involved inspection of the house .. it takes a few hours. I wanted to upgrade an older part of the house -- this was going to require insulation and other equipment work anyway. This was two years ago and I hit the 25% savings if I did the insulation upgrades and equipment change ,,, back then the program provide 5k in rebates and 10k. I ended up replacing both of my systems .. and basically got the insulation and 1st system for free. I'm saving way more than $88 dollars a month on my bill -- the cost of 10k for 10 years at 0%. The second system was 13k .. it's like living in a different house.

FYI -- most times they close off the attic. None of my places have ventilated attics.

 

[47WDXPW]

I did call and they are coming out tomorrow thanks. In the info portion of the site they do mention closing off the attic. Is it possible to get the garage insulation in as part of the percentage ?

 

[DC73]

Cellulose is the most effective. In cost per R value, in air sealing(at least in your specific situation) and is better in a fire.

I agree with Firebrick43. Cellulose is very likely the best bang for the buck in insulation, especially when you are going to blow it over existing fiberglass batts. It will help stop air flow through your fiberglass insulation and make it more effective.

If you decide to go with more fiberglass, you could either blow it in or install unfaced batts perpendicular to the existing batts.

DC

 

[chrispyny]

I won't get into fire ratings and which is better, but i have a concern.

47W said the insulation in the attic is paper backed. As far as i know, thats a problem. Vapor barriers in attics are bad.

 

[Firebrick43]

I won't get into fire ratings and which is better, but i have a concern.

47W said the insulation in the attic is paper backed. As far as i know, thats a problem. Vapor barriers in attics are bad.

The paper is against the ceiling in the proper place. There is nothing wrong with a vapor barrier in this location. As DC73 alluded to, if there is another layer of fiberglass they must not have a paper backing but be unfaced as a double vapor barrier, anywhere in the building envelope, is bad.

 

[yeldogt]

I did call and they are coming out tomorrow thanks. In the info portion of the site they do mention closing off the attic. Is it possible to get the garage insulation in as part of the percentage ?

Ask -- part of mine was in the attic of the garage. You don't have to go with the first contractor -- additional estimates from other contractors is allowed under the program. The site has a listing of all the contractors eligible -- some do a lot of them.

It's sort of a one shot deal -- the state wants you to upgrade everything. If you pay now to upgrade the insulation (outside of the program). Then in a few years you need new equipment ... the rebate and loan amount will be based on the now tighter house ... so the saving will be less.

They do a full load calculation -- and they do another blower door test at the end.

 

[yeldogt]

The paper is against the ceiling in the proper place. There is nothing wrong with a vapor barrier in this location. As DC73 alluded to, if there is another layer of fiberglass they must not have a paper backing but be unfaced as a double vapor barrier, anywhere in the building envelope, is bad.

I think he is talking about the typical VB on the batts -- it would be against the drywall.. No problems.

The typical fix is to lay unfaced batts in the opposite direction on top of the current or to use a loose fill product on top.

With many/most houses the ceiling leaks -- plumbing and electrical holes -- recessed lights -- chimney gaps. The natural pressure of heat rising pushing through into the attic .. this brings moisture. The attic is open and offers no resistance. The buildup of heat will cause ice dams.

without the leaks and a closed attic -- enough insulation ... problem solved.

 

[amalik]

I'm currently going through this **** also. Attic is sitting at 'R6' equal and need to get it up to R49 or so.

If you don't air seal the leaks first, there is no point of adding insulation - it will end up as a huge 'air filter' if you dont seal leaks VS acting as insulation.

I've done a ton of research and blown-in cellulose is much better than blown-in fiberglass and also has fire retardant built-in.

 

[47WDXPW]

So far sealing up the attic space is part of the deal, they will strip back one half of the attic at a time air seal and then do the other half so I'm guessing that removing the ridge vent is part of the plan too. The rep said providing R50 is part of the plan. Since my heater is a newer unit a tankless water heater would also be part of the plan. Thanks for mentioning the attached garage since its sealed I usually forget about it. When I said garage I meant a detached 30X48 in the back yard that needs to be insulated, we will see. Load calcs blower test (air pressure) and a few more he said a lot. One was to se if there is enough gas pressure for a tankless set up. This will be a good opportunity to see if a NG generator would be supported by my service.

 

[yeldogt]

So far sealing up the attic space is part of the deal, they will strip back one half of the attic at a time air seal and then do the other half so I'm guessing that removing the ridge vent is part of the plan too. The rep said providing R50 is part of the plan. Since my heater is a newer unit a tankless water heater would also be part of the plan. Thanks for mentioning the attached garage since its sealed I usually forget about it. When I said garage I meant a detached 30X48 in the back yard that needs to be insulated, we will see. Load calcs blower test (air pressure) and a few more he said a lot. One was to se if there is enough gas pressure for a tankless set up. This will be a good opportunity to see if a NG generator would be supported by my service.

Do you get gas from PSE&G or SJG? PSE&G ran a new 2" line and meter to the house for free .. SJG made me pay for my shore place.

 

[47WDXPW]

I have SJG, ugg.

 

[47WDXPW]

Looks like we agreed to a insulation only project house attic and garage attic with the garage having a access panel installed. Sealing the attic floor only so venting stays and the state picking up 40% of the costs. Also found out that my heater didn't have the combustion air intake piped to the outside for fresh air intake. They are guaranteeing a no more that 2* temp difference from the first floor to the second floor which is for me the main benefit of a project like this. Also they will only use blown in fiber glass no cellulose allowed for air quality reasons.

 

[FTG-05]

I JUST HAD 6-8" of blown cellulose added to my attic floor, including my garage. HUGE difference in before/after temps, especially in the attic. Much cooler there. While they were up there, they also added that R-5 pink styromfoam to my attic walls over the garage, where it gets the sun most of the day and to my knee wall above our kitchen.

House temps are now much more stable and even though temps are the same, it feels cooler and more comfortable. Only a week in right now, so no data on utility bills reductions as yet.

 

[Scott H in Wheaton]

Looks like we agreed to a insulation only project house attic and garage attic with the garage having a access panel installed. Sealing the attic floor only so venting stays and the state picking up 40% of the costs. Also found out that my heater didn't have the combustion air intake piped to the outside for fresh air intake. They are guaranteeing a no more that 2* temp difference from the first floor to the second floor which is for me the main benefit of a project like this. Also they will only use blown in fiber glass no cellulose allowed for air quality reasons.

I think you done good.

Ridge vent per your previous comment must stay in place as part of the roof venting system. It allows built up heat to escape in the summer and any winter moisture/condensation to also escape.

re: fire retardant capability of fiberglass...glass melts, but is not a fuel source. You can't build a campfire with fiberglass kindling. Cellulose is most often recycled paper such as newspaper and phone books...excellent fire starters unless they have the boron/boric acid treatment, which most do.

 

[yeldogt]

I think you done good.

Ridge vent per your previous comment must stay in place as part of the roof venting system. It allows built up heat to escape in the summer and any winter moisture/condensation to also escape.

re: fire retardant capability of fiberglass...glass melts, but is not a fuel source. You can't build a campfire with fiberglass kindling. Cellulose is most often recycled paper such as newspaper and phone books...excellent fire starters unless they have the boron/boric acid treatment, which most do.

They close them up in NJ -- the vents allow moisture to enter. Closed is best -- same with crawl.

 

[Rascal]

I am looking to do this myself next weekend. I am curious about prep; I assume I should stay away from recessed lighting and anything else that generates heat? All the videos online just show guys spraying this stuff knee deep. Doesn't seem right.

 

[Firebrick43]

The lights depend. Many new lights are ic rated (insulation contact). Many older ones are not and should be either changed out(most cans are under 15$) or build a drywall box to go over the can.

Other prep included making sure the soffits are blocked off and vent chutes are in place.

 

[47WDXPW]

They close them up in NJ -- the vents allow moisture to enter. Closed is best -- same with crawl.

yeldogt, I talked to the rep about sealing and they do not remove the venting from the house, the ridge vent stays the sealing has to do with the attic floor only to seal the house.

 

[47WDXPW]

Also my home was built with a 1" layer of foam board sheathing the house and not plywood. It has vinyl siding hanging from this. With the 1" foam board and fiberglass glass installed in 2x4 studs what kind of R value would this be ?