Is blow-in insulation cost effective in new construction, or even possible to use?

[Michael Yadfar]

I'm near done insulating my very small 9'x16' shop, which isn't new, but has never been insulated. I used a combination of foamboard and Fiberglass insulation to do the doors, floor, ceiling, and walls. All in all, the cost was about $800, and that's without drywall or any wall covering which I don't plan to do, I figure if the shed catches fire, it will be a goner whether the foamboard is exposed or not.

Anyway, my uncle said it would have been cheaper to use blow-in insulation. I've heard of it for attics and insulating uninsulated walls in historic homes, but I've never heard of it used in new construction. Even after looking it up, I can't find any example of it used for this kind of purpose, so I figure it's either not cost effective or not possible to use.

[Chris Friesen]

Blown-in fiberglass was cheaper for my garage roof than using buying batts.

However if you have a cathedral roof it probably wouldn't make sense, and for a small shop like yours the cost/hassle of the blower might make it not worthwhile.

[Lee Schierer]

Blown in works fairly well in ceiling applications, but often leaves gaps in walls and does tend to settle over time. Of course to do walls you have to have an inside and outside wall covering.

[eugene thomas]

for ceilings blown in works better if not to steap a pitch cause fills in all the voids around the framing members . but for shop your size might be easier just to use batts.

[Gary Yoder]

There is more than one kind of blown in insulation. what a lot of people are talking about is blown in dry and used in ceilings and or into walls of old homes. there also is a type that is blown in damp and is used in new construction. The R value is similar to batt but is tighter. It doesn't settle, but takes special equipment to blow in. We built our house 4 years ago and the cost was similar to fiberglass batts.

[Joe A Faulkner]

My guess is that your biggest cost was in the rigid foam board, not the batted insulation. For a job this size, I doubt you would have saved much going with blown in insulation. I've seen it blown in new construction - step 1, put up a vapor barrier. Step 2, cut holes near the top of the wall cavity in the vapor barrier, step three blow it in. If done correctly, the blown conforms better to outlets, wires, etc. than batts.

[Howard Acheson]

Many, if not most, of the new construction homes in coastal North Carolina use a combination of "blow in" insulation and fiberglas batts. According to the builders I have spoken to, "blow in" is cost effective and fills nooks and crannies more effectively.

[Jerry Bruette]

My house was built in 1988 and it's insulated with blown in cellulose. In the side walls the damp method was used and there are no gaps at the top. I have one inch thick foil faced iso foam sheathing and 2x4 walls.

The blown in cellulose makes for a very quiet house and I think it cuts down on infiltration better than any fiberglass product would.

[Al Launier]

My current home was built in 1997 & the Blown In Blanket system (BIBS) was used to completely insulate the house. I can honestly say that this is the best insulated house I've ever had (5 new). There have not been any leaks from the typical locations, outlets, wall penetrations, etc. No wind penetration at all except from a couple windows that have worked loose from settling. It's my understanding that the shredded fiberglass has a some sort of adhesive in it that allows the insulation to stick to things & doesn't sag like regular blown in insulation. This was one of the best decisions I made when having this house built. My next home, if there is one, will also have the BIBS insulation.

[Michael Yadfar]

I heard the future in home building/ insulation is SIPs, structurally insulated panels. I learned all about these and I believe they would be cheaper than blown in insulation simply because it saves a lot of installation time and cuts down on waste. As for my shed, it's obviously not new so that wouldn't be the way to go, but if I built a new shop it may be SIPs. Although foam board is very expensive, and spray in is relatively cheap, the thing I debate, which the quedtion is based off of, is what would have been cheaper.

[Jim Andrew]

Blow in cellulose or fiberglass insulation for ceilings is fairly inexpensive vs batts, but you have to add stops around the outside of the building, and put some spaces in to keep the insulation from blocking your vents. I would cut scrap waferboard or plywood and fill the spaces between rafters above your walls except for the top 3/4". Where you have a soffit vent, would put a pair of 2x2's fastened to the upper edge of the rafters and put a piece of ply or wafer under that to create a space to keep the insulation from clogging the vent space. If you do not block the overhang, the insulation can slide out into the soffit when you blow the attic space, and also wind storms can blow the insulation away from the edge of the building.

[Terry Therneau]

The pros that insulated my shop this year used blow-in for the ceiling. They first tacked up mesh, about 1/4 to 1/8 inch grid using a tack hammer, then he'd cut a little "X" in it near the middle, slide the hose in till it was near an outside wall, and then pull back slowly as the insulation filled, turn and repeat the other direction. He had a remote that turned the feed on and off at will, wore stilts. Plastic vapor barrier was added after they were done. Two guys covered a lot of ground in an hour.

Terry T.

[Jason White]

http://www.bobvila.com/sections/more-home-improvement/projects/12-manhattan-remodel-and-cape-cod-affordable/episodes/151-cladding-insulating-and-zoning-for-an-affordable-home/videos/1089023202001-the-blown-in-blanket-insulation-process#.U_n_uUvydG4


I'm near done insulating my very small 9'x16' shop, which isn't new, but has never been insulated. I used a combination of foamboard and Fiberglass insulation to do the doors, floor, ceiling, and walls. All in all, the cost was about $800, and that's without drywall or any wall covering which I don't plan to do, I figure if the shed catches fire, it will be a goner whether the foamboard is exposed or not.

Anyway, my uncle said it would have been cheaper to use blow-in insulation. I've heard of it for attics and insulating uninsulated walls in historic homes, but I've never heard of it used in new construction. Even after looking it up, I can't find any example of it used for this kind of purpose, so I figure it's either not cost effective or not possible to use.

[Mark Bolton]

We use blown in new construction quite a bit especially in ceiling and floor structures using engineered material as we often use a 19.2" spacing and bats dont work there.

As has been stated its far better at conforming to obstructions and wires especially around things like recessed ceiling cans. There is no simple detail to deal with cans with bats and blown is the way to go. The damp method for wall cavities is best but we dont have access to it in our local area. We use continuous poly vapor barrier throughout with unfaced bats in the walls and blown in most ceilings but we take a lot of pains with splitting bats around wire runs, switch and receptacle boxes, and so on. Most insulation contractors around here simply stuff the bat and barely cut around boxes or tuck behind and they nearly never split their bats around wires so we do our own.

One thing to be conscious of though is if your blowing over drywall ceilings you want to be carefull about the drywall's rated capacity. Its easy to get carried away thinking more insulation is better and if your ceiling is framed 2' on center you can easily meet the drywall capacity with and R-30 - R-38 fill.