Attic insulation

[Learninggal]

2-level house & basement in HVAC climate zone 4 and taking out all of the old attic pink batts insulation since it's worn out. Once old insulation is out, they will do air sealing before re-insulating. Contractor is through a state funded program and they only allow fiberglass or cellulose on floor of attic (rafters not allowed). I have my HVAC furnace & A-coil in the attic too but both aren't used much. In the winter, the basement unit warms up the whole house nicely and in the summer, we turn on this attic AC only 10-15 of the hottest days. New roof as well. Decision is up to me and they'll put in R48 value which is what state allows. Would you choose fiberglass or cellulose?

2nd question. He's also doing rim joists in basement but won't touch boiler room. The state regulation is 6ft away from any combustion equipment like my 50 gallon water heater and there are too many pipes going out so not much place for him to place foam board and seal it. Have you folks heard of this 6ft requirement before? He made it sound like not a big deal since it's only 10% of the whole basement and thinks it's good to air out the boiler room and allow some fresh air in

Thanks

 

[PCustoms]

What state?



Regarding the boiler room, if it needs combustion air that should be designed into whatever you are doing, not relying on building leaks to pull air in...

 

[NUTTSGT]

I prefer fiberglass. I hate cellulose because of my career and what it does during structure fires. . . a serious PITA.

 

[billconner]

Everything I've read is cellulose performs better and more safe than fiberglass in a fire.

I don't believe fiberglass insulation wears out. If wet, moldy, or rodent infested, that is reason to get rid of it. Feels like an opportunity for additional profit for contractor. I'd like cellulose on top of fiberglass. I went to 20 inches - over R60 - and no regrets.

 

[PCustoms]

I hate cellulose because of my career and what it does during structure fires. . . a serious PITA.

Everything I've read is cellulose performs better and more safe than fiberglass in a fire.

So which is it? I've always heard better in a fire as well....

Feels like an opportunity for additional profit for contractor.

I suspect this is part of some energy audit/rebate program, but the OP is either misinterpreting or missing some details. I have never heard of a "maximum" R-value or the regulations around the HVAC...

 

[NUTTSGT]

So which is it? I've always heard better in a fire as well....

Well there's lab tests and there's real world.

I don't care what the "experts" say on paper, real world experience . . . this stuff smolders and holds heat. If there's a penetration in a ceiling where comes through, pull the cellulose back about 4' away and I bet it's charred black where it has smoldered. It'll hold heat until it reignites.

Almost every rekindle we have had in the 25 years I have been at the FD, can be traced back to blown cellulose insulation, with the exception of somebody "re-torching" a structure.

 

[Learninggal]

I’m in NYC. How can someone seal up and insulate the rim joists area in the area and is it a good idea given these pipes could need some maintenance in the future?

 

[PCustoms]

I’m in NYC. How can someone seal up and insulate the rim joists area in the area and is it a good idea given these pipes could need some maintenance in the future?

I would spray foam the rim joists.

But, I would make sure that any rot, open electric boxes leaking pipes are resolved first. There looks to be some opportunities...

What's with the metal stud track along the ceiling?

What is your furnace/boiler? I'll say it again, I'd you're doing air sealing you should make specific plans to allow for make-up air, not just keep a section of rim joists leaky.

 

[NUTTSGT]

Is that dryer vent ? Please get rid of that ****. . . . woof ! That **** is gone when fire hits it.

 

[Learninggal]

1. What should I replace the dryer vent you see with?
2. Furnace is a Bosch 40k
3. What would I have to do to have a closed system to provide combustion air intake for the rheem Performance 50 Gal. Short 6 Year 40,000 BTU Natural Gas Tank Water Heater. I looked up the manual here and can’t find much - https://images.thdstatic.com/catalog/pdfImages/a5/a501ac67-85ea-4a23-a023-76cccfa0fe15.pdf

It has inlet openings at the bottom to pull from the environment

Thanks

 

[kngelv]

Cellulose is much better as an insulator than fiberglass. Don't know enough to debate the fire side. Rockwool is better than both.

James

 

[NUTTSGT]

4" metal duct would be my choice..

The aluminized stuff, I would say is fine for a short distance..

Dundas Jafine 4"x8' Aluminum Duct Vent Pipe Connector Kit at Menards® https://share.google/MuxXU2uvgwE96a7a2

 

[PCustoms]

1. What should I replace the dryer vent you see with?
2. Furnace is a Bosch 40k
3. What would I have to do to have a closed system to provide combustion air intake for the rheem Performance 50 Gal. Short 6 Year 40,000 BTU Natural Gas Tank Water Heater. I looked up the manual here and can’t find much - https://images.thdstatic.com/catalog/pdfImages/a5/a501ac67-85ea-4a23-a023-76cccfa0fe15.pdf

It has inlet openings at the bottom to pull from the environment

Thanks

That dryer vent is hooked to a dryer, correct?

 

[Learninggal]

Yes it is

 

[csp]

For your dryer vent use rigid 4" galvanized duct with no screws holding it together, just aluminum tape.

It's a shame that you can't use rockwool. We're doing a kitchen remodel and sucked out a portion of our attic's blown in fiberglass and I just put rockwool in it's place. Same with the walls. I notice already that it's less drafty and more quiet.

 

[Learninggal]

How old was your fiberglass

 

[Uncle murph]

How old was your fiberglass

This has been a very interesting thread.

 

[CraigStu]

Our heat pump has propane backup. The air inlet is 3" pvc. I suspect that was just easy for the installer but it has worked fine for 6 years.