Cellulose vs Fiberglass Insulation - Another Perspective

[@bmo5082]

Thanks Martin. I am building a new home and was presented with both of these products as options for my attic. Fiberglass was a little more expensive, so I thought it was a superior product. Seeing this makes me think that I’m ok to stick with cellulose.

[@keithbarto5464]

There are still good reasons not to spray cellulose in attics not covered here in this video. Example: If a homeowner develops a leak or breach in the roofing/decking that isn't detected quickly after a period of rainy days or weeks and the cellulose gets repeatedly wet...it gets HEAVY. By the time they notice the sheetrock has water damage and reveals a leak has been going on unbeknownst. .. cellulose absorbs the water like a sponge and the significant added weight it brings can be enough to cause the damp sheetrock to collapse the ceiling before the owner can get the problem assessed and addressed. The fiberglass..while being less adept at attempts to re-fluff and yet more expensive... IS STILL worth the trouble. Most cases needing a company to do a "build up" (second attic spray- over) is justification bc most times it doesn't settle much below r-value to require those build ups to spray more than just a few inches and is not a *bank breaker* financially. .vs the alternative- The BIGGEST REASON to spend extra and avoid cellulose is that wet fiberglass isnt as problematic not only in terms of weight and is VERY flame resistant ...but MOST MPORTANTLY . ..Is ALSO not a conducive substrate to foster or promote the growth of dangerous "black mold" spores and mildew damage...whereas wet Cellulose IS an environment that offers reduced resistance to dangerous mold growth AND is not AS effectively flame retardant Like fiberglass, though it DOES have fire retardant additives like 'borate' etc..to assist in it not burning easily..but an attic fire big enough to be a concern doesn't need any help from cheap insulation to fuel it's destructive ability, so the flame retardant issue is not as relevant as the damage that wet Cellulose can exacerbate into costly and potentially dangerous importance. Adequate humidity control and attic ventilation is what the fire retardant issue is important to understand. The cheapest Cellulose often uses ,not the less hazardous Borate...but AMMONIUM SULFATE, and wet Cellulose with Ammonium Sulfate additives can cause the dangerous "off-gasing" of ammonia when the Attic can't "breathe" correctly. Borate doesn't "off-gas" and is what you want to have as the fire Retardant additive( if you must use cellulose at ALL ) Cellulose is mostly ground up newspaper and glue,.. obviously made of things that CAN still burn when exposed to a large enough fire source.. It's not a fire hazard.but not invincible either but tbh...it's the danger of moisture that is why it's not preferable in attics It's cheaper to spray cellulose... especially in new construction but homeowners that have to pay for a re-fluff/build up out of pocket are even more apt to allow it when they don't consider the pros and cons of WHY it's not a scenario to financially cut corners on, without understanding the potential consequences. Fiberglass is more expensive to make but is SAFER by far in the long run..An attic fire is a threat with or without either type needed to ruin lives.. Excessively wet (saturated)cellulose is not remotely lightweight, and WILL not stop mold spores and mildew. AND Ammonium Sulfate can result in "Off-gassing" That's WHY you should leave it out of attics If it can be avoided. If you must,...at least know what you're dealing with beyond the realm of cost effectiveness vs potential hazards and avoid the super cheap version. Ammonia is not a safe thing to be exposed to.

[@bmo5082]

@@keithbarto5464 good to know. Lucky for me I live in a very dry climate.

[@ericwotton2046]

I'm a service electrician in the northeast. When I'm working in an attic I sweep the insulation to the side with some cardboard, then put it back with a broom and whip/fluff it with a fiberglass fish rod that i typically already using in the attic.

[@HouseKnowHow]

I love that you do that! I wish there were more electricians that did that as well.

[@DavidLeBlanc]

When people mention cellulose is dusty, they weren't kidding.

[@tomclose6643]

can i blow fiberglass over existing cellouse that was blown over fiberglass batts from original build?

[@fortisfabrications4558]

No.

[@chadridsdale9970]

Why not?​@@fortisfabrications4558

[@TheBalognaPony]

Watching you pour small side to small side drove me insane......pour thin side to broadside and you'd have spilled 0 🤣

[@cv6717]

Would a vapour barrier on top of 50mm cellulose cause an issue close to warm side of insulation as its hydroscopic? I have 270mm fibreglass on top between loft joists.

[@terryeffinp]

I did blown fiberglass in the attic of our place. For a few reasons, the machine is super easy to operate. My best girl had no problem loading it and keeping things going while I was up in the attic. Two the dust is minimal (all things considered given the process). The coverage per bag is amazing. I do my best to be careful not to squish the insulation if I need to access the attic. The walls which we did just yesterday, a different story. Blown in cellulose. She did not help on that, nasty process. My brother helped me. Blown fiberglass not so good for existing walls.

[@ratoneJR]

How can you smash insulatoin in the attic? You will break through the drywall cieling.

[@danbillig442]

Seriously?… Uh, you step on the truss and step down or compress the insulation onto said truss or “drywall ceiling” support.

[@venegasenmerida6307]

What do you reccomend if unfortunatele some of it has been stomped on fiberglass & no budget for another round of blown in

[@HouseKnowHow]

Fluff it up as best you can.

[@venegasenmerida6307]

@@HouseKnowHow thanks I Will

[@Victor-th8tb]

Hello. What's attic insulation do you recommend for Orlando, Florida?

[@HouseKnowHow]

I'd probably stick with cellulose. But you might want to check around with some local energy auditors. Do not ask insulation companies. They tend to want to sell you what's easiest for them to work with.

[@Victor-th8tb]

@@HouseKnowHow Thank you very much.

[@BenKlassen1]

Leaning towards rockwool>fiberglass>cellulose. Cellulose can offgas ammonia. All seem to compress down significantly from initial blown in depth.

[@thomasschafer7268]

Wo soll denn das Ammoniak herkommen.

[@BenKlassen1]

@@thomasschafer7268Google is your friend: Cellulose Insulation: Ammonium sulfate and boric acid are fire retardants commonly found in cellulose insulation. Occassionally, the ammonium sulfate can off-gas and produce an odor. In damp environments, it can also form corrosive byproducts that can degrade metal that it comes in contact with.

[@jms6605]

@@BenKlassen1if you have good ventilation you should be good.

[@corykeeler2655]

I have good ventilation and the wind blowing in from soffits forces smells through the areas where walls are in the attic. The smell was unbearable. I had to go up and air gap seal all gaps with foam.

[@EvieCohen]

Interesting. Well done video!

[@HouseKnowHow]

Thanks for the kudos Evie!

[@charlespaine987]

All loose insulations settle down accumulate additional dust . Personally mineral wool batts combined with a 1’’+ spray foam is most effective long term. Mineral batts are easer to move intact tend to collect less dust and not hold water like cellulos

[@ryan74701]

No shit dude, but mineral batts and spray foam are way more expensive. I have one inch of spray foam in my shop and it’s great for air sealing, if I built a house I’d definitely spray foam the walls and attic or at least mineral wool my walls and spray foam the attic. But most people don’t have the money to do these things, my current house has fiberglass and we are about to add ten inches of cellulose right over it after air sealing.

[@jheisel1]

Thanks Martin, good one!

[@HouseKnowHow]

Thanks John, I appreciate it!

[@Grimsaitis]

If it is no secret, what is the normal hourly rate for such work?

[@HouseKnowHow]

It really depends on where the work is done as rates vary all over the country. Sometimes you will get a quote for the entire job instead of an hourly rate.

[@tha073926]

You will most likely get quoted per sq foot of your house. Can range from $4 to $6 if you are looking to remove and replace insulation. If just adding more, maybe half that price? Only way to find out is to get estimates.

[@yorkrojas1452]

Amazing!!

[@rideoregonfirst]

The ridiculous amount of dust given off by the cellulose is the deal breaker. Who would put anything that dusty in their home? That dust is full of nasty fire retardant.

[@martinnewmark2716]

I go with cellulose because it's only dusty when installed and does a better job insulating. And, most of the dust is in the attic, not in the living space.

[@theripper121]

If you are air sealing properly and not up in your attic daily stepping all over it the dust really won't ever end up in your living space in any measurable meaningful way....

[@HTHAMMACK1]

Who cares if it's a better insulator. Are you going to hang out in the attic?

[@MissAshlee]

@@HTHAMMACK1 ... the whole point is to insulate the house, not the attic.

[@terryeffinp]

Just did the exterior walls on my place with cellulose yesterday. From the inside. We have aluminum siding, good luck removing it without damaging it. I am not removing hundreds of square feet of siding to insulate. It is what it is. Punch the holes, blow it in, shove some fiberglass in behind it, clean it up, fix the plaster.

[@wty1313]

Unless you regularly shake your house around or walk the entire attic directly on the insulation, the amount of agitation and compression being done to both products is a little unrealistic.

[@Beaster456]

I really don't get the benefit of blown in fiberglass then at all. It's 2-3x the price per bag, it has a worse R value and it really does not fare well against being stepped on.

[@HouseKnowHow]

You can't just compare the prices of 1 bag of cellulose the 1 bag of fiberglass. You need to compare the final coverage area and thickness that each bag yields. That way you can calculate the cost per square foot of say R50 of each product. My opinion: As far as the benefit of fiberglass, it all goes to the installer. It's much less messy (dusty) to install fiberglass. That's why most homes have it. And fiberglass marketing is a well oiled machine. It's much better than the cellulose one. And, they market to installers more than homeowners.

[@bfullsyou]

My brother had a new home built. All blown in fiberglass in attic. The outside winds blew his new insulation away from the eaves. He soon began getting water dripping down his drywall, outside walls. Do not know what he did upon thereafter. What a headache... brand new home.

[@Smokeey409]

Tell him to install insulation baffles, sounds like what caused it was windwash from air entering the soffits.

[@gerdberg4188]

Not built right , that sucks

[@jerryashenfelter8181]

At least he was smart enough to replace the government mandated gas can spout.

[@venegasenmerida6307]

Do NOT STEP on the insulation!!! Thanks for the demo. Now Will be going up to the attic with my egg beater 🙈.

[@Nightl3lade]

man watching all that cellulose dust, im glad i decided to just go with fiberglass. i really did like the extra R value from cellulose though

[@jamesschneider6136]

very very dusty! I am shocked!

[@peacefrog0521]

Handling fiberglass with your bare hands? 🤦🏽‍♂️

[@HouseKnowHow]

Yes! The newer blown fiberglass products do not give you splinters like the old stuff. It's a nice feature, but I still prefer cellulose.

[@peacefrog0521]

@@HouseKnowHow you’ve got balls of steel to do that 😀 Yeah after watching this video I kind of regret getting blown-in fiberglass for my attic. It works but meh.

[@terryeffinp]

It isn't that bad. You get a little itchy. Not a big deal.