# Blown in insulation....after drywall



## J-Peffer (Mar 3, 2007)

I bought a home to work on when I have spare time.....2 years ago....not much spare time.

I am finishing up the last of the framing and running the phone lines/cable lines this week.

Insulation and drywall is the next step.

I really wanted to blow wet cell on the walls, but I can't really do that myself as I don't have the equipment. I wanted to make the house pretty tight, keep a respectable heat bill and have installed a nice efficient furnace to help control that cost to make it more marketable.

I already foamed behind all the outlets and hit the problem area's with foam.

But I don't want to drop 5k to have a company come in and spray the walls. I bought the house to keep me and my guys busy, so have to make money to compensate.

I was thinking of just blowing in the walls, after I get the drywall first coat up.

I was just going to blow from the inside, and finish over the holes rather than the outside.

Someone had told me, it's actually better to do a hole at the top, and a hole at the bottom. then Blow in from the BOTTOM until it come out at the top.....

Any tips?

I've foamed a lot, base plates, around all windows, outlets, caulked between sill plates, foamed around holes for wires and plumbing.


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## JonM (Nov 1, 2007)

At the top and halfway down the wall you should have openings...:thumbup:


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## neolitic (Apr 20, 2006)

Are you talking about 
blowing loose fill?
That's kind of 50's.
Vapor barrier is problematic,
not to mention settling.
Did I misunderstand?


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## Joasis (Mar 28, 2006)

If you have access to an insulation blower, you could, with a little ingenuity, rig a nozzle to spray the cellulose for the wet blown walls. If you buy cellulose with any corn starch used in it, it will be self setting, meaning no glue needs to be added. 

You might take a look at Krendl's web site to see what the nozzle looks like, and for $20 bucks, make one. 60 psi of water pressure or so, and you are in business. 

I would not loose fill the walls.....however, on older home, we have drilled the top plate and shot it in with a 1 inch sweep fitting.


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## tcleve4911 (Mar 26, 2006)

Our local lumber yard sells the 2 part foam sprayer as a kit. It sells for about $400.00 and can do a certain amount of square feet / inch of thickness. It's a setup that's for a one time application. You might have to buy 5 or 6 tanks but you're still ahead of the game with this DIY setup.....
Blown-in?.......that's just so 70's...............:no:


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## Joasis (Mar 28, 2006)

Sprayed cellulose has probably 95% of the insulation market here, and I would suspect, about everywhere. You want expense, put a pencil to the spray foam kits and see about $1.30 a board foot applied. My son charges .55 for 4 inch walls and .65 for 6 inch walls, cellulose. Attics command .75 for an R30 or 8 inches of loose fill.


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## WarnerConstInc. (Jan 30, 2008)

Has anyone heard about the blown in blanket system. My neighbor does that, they staple up a fabric of sorts and then blow in chopped fiberglass (white). It gets in all the nooks and cranny's and is super sound deadening. I think it is very reasonable. If I remember right you get R-15 or 16 in 2x4 walls.


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## Joasis (Mar 28, 2006)

I still believe cellulose outperforms fiberglass hands down, no matter how it is applied. Cellulose can also be netted and blown (what you described above) but glue set is tighter.


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## GreginAlaska (Mar 22, 2008)

I wonder if this could help you?

http://soythane.com/


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## J-Peffer (Mar 3, 2007)

I know doing it, is really 1970's.

But if I buy this house, sub everything out to contractors......it's a pointless purchase.

Just going to do a hole at 4' and a hole at the top.

If I pay a insulation contractor to foam the area's I want, and use blowing in before the drywall, I'll be racking up 6k. I mite as well get a drywall company in then too. 

It's not a million dollar home, I like to do things write, but some projects have budgets also. I would never get the ROI by hiring companies for this house. It could be Trump Tower and it won't sell for over 80k in the area it is in.

Just trying to do the best can I can, with out loosing money.


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## JonM (Nov 1, 2007)

With cellulose, you only need 2-1" holes....:thumbup:


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## WarnerConstInc. (Jan 30, 2008)

The blown in blanket thing is fairly inexpensive.


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## neolitic (Apr 20, 2006)

I forget now, why not just
batt it and move on?????


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## MBS (Mar 20, 2008)

*A way to do it right*

I used to do a lot of blown-in cellulose in older existing homes. The method of drilling a couple of 1 inch holes and blowing it in, is that it is a very poor method that simply does not produce results one would be proud to put their name on.

Usually, a one foot diameter plug will be formed around the hole and the installer thinks its full. Then months later the plug finally falls to the bottom of the cavity. There is no way to get the desired density with that method. Even in the rare instance where the cavity may accidentally get filled, the density will be so light that it will eventually settle and maybe the lower half the cavity will actually be insulated.

I developed a method that actually works and fills the enclosed cavities to the proper density, and no settling can occur. Here's how it works:
Get an 8 foot piece of 1" plastic gas line. Use gas line because otherwise the static discharges every 4 minutes will fry your central nervous system. Attach the plastic gas line securely to the hoses' shutoff nozzle. 

From the outside of the building, remove the siding, at the rim joist area to about a foot above the floor, if its already on there. Then cut a 1-1/2 inch wide slot about 6 inches long into the sheathing just above the wall plate into the center of a cavity. I used a saws-all for this. Very fast. 

Now slide the plastic tube all the way up into the cavity until it hits the top plate. The tube will be curved, so let it curve back out towards the outer wall and it should glide right up there.

You'll know your at the the top plate because you can gauge it by the length of the tube. If it doesn't go all the way up, you know you hit something, and where in the wall it is. 

Pull the tube out about 4 inches and open the valve and let the insulation fill the cavity. It will fall and fill from the bottom up and you will be able to tell how its going by the amount of insulation that is going into the cavity. You can tell by the sound of the machine when the cavity is full, because the insulation will stop flowing. Also, the very top of the cavity will now be packed to proper non settling density, but the lower portions are not.

This is crucial; leaving the valve fully open, draw the tube out about 9 inches. The machine will then pack that section to proper density, repeat until the entire cavity is packed and the tube is completely out. This would be a good time to close the valve too. 

You can run right down the wall with this method and be assured that you are doing a proper fill job. I would attach aluminum flashing over holes and reinstall the siding. Two guys can insulate an entire house in a couple of hours this way.


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## J-Peffer (Mar 3, 2007)

neolitic said:


> I forget now, why not just
> batt it and move on?????


Some of it is, but batts are costly compared to blown in. Also most of the exterior framing on this old home, is not accurate. Not many 14.5" openings between exterior studs.


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## J-Peffer (Mar 3, 2007)

MBS said:


> I used to do a lot of blown-in cellulose in older existing homes. The method of drilling a couple of 1 inch holes and blowing it in, is that it is a very poor method that simply does not produce results one would be proud to put their name on.
> 
> Usually, a one foot diameter plug will be formed around the hole and the installer thinks its full. Then months later the plug finally falls to the bottom of the cavity. There is no way to get the desired density with that method. Even in the rare instance where the cavity may accidentally get filled, the density will be so light that it will eventually settle and maybe the lower half the cavity will actually be insulated.
> 
> ...



Interesting, I like the idea.

What if you just started at the top....and blew in from the top with the tube starting at the bottom? it would blow in more dense and you would work your way up, and out the top hole.

I had thought if you could get a wall attachment with a bend in it, that would work too. I thought of having a muffler shop bend one. Drill the hole, and stick it in.

Imagine the peice looking like "gonzo's" nose, lol.

It would blow in more compact it seems.


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## neolitic (Apr 20, 2006)

J-Peffer said:


> Some of it is, but batts are costly compared to blown in. Also most of the exterior framing on this old home, is not accurate. Not many 14.5" openings between exterior studs.


By the time you get done 
cutting, patching, futzing around
with the the blow-in.....
R-13 unfaced cuts easy, 4 mil
visqueen.....
I still don't see an advantage,
and dry blow-in will settle.

Go[d luck with it.


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## MBS (Mar 20, 2008)

neolitic said:


> By the time you get done
> cutting, patching, futzing around
> with the the blow-in.....
> R-13 unfaced cuts easy, 4 mil
> ...


Dry blow-in cannot settle if installed at a density greater than it's settled density. In other words when done correctly. Its not hard to do. That settled density is specified on the bag. Actual installed density can be calculated and verified at the time it is being installed with a little math. 
My method works very well at exceeding the settled density every time.


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## MBS (Mar 20, 2008)

J-Peffer said:


> Interesting, I like the idea.
> 
> What if you just started at the top....and blew in from the top with the tube starting at the bottom? it would blow in more dense and you would work your way up, and out the top hole.
> 
> ...



Just blowing it into the wall without the tube method will not pack the insulation to exceed the settled density. Therefore it will not be a good job. The whole reason a tube is inserted into the cavity and removed a little at a time is to pack the insulation tightly and evenly. If you don't do that, its not worth doing at all. 

Cellulose only packs at or beyond the settled density within about a foot of the blow-in point. The only way I know of to achieve that, is to move the blow-in point through the entire cavity. Anything less will produce less. 

Doing it from the top is a real pain due to the overhangs. Its impractical. You have to work off a ladder or scaffolding, and you can't get under windows. A single angled tube will not attain the same results. The insulation will settle.

Cellulose only packs at or beyond the settled density within about a foot of the blow-in point. The only way I know of to archive that, is to move the blow-in point through the entire cavity. Anything less will produce less. 

  
I've done this on over a hundred homes years ago and refined the method for quality, speed and efficiency.


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## neolitic (Apr 20, 2006)

MBS said:


> Dry blow-in cannot settle if installed at a density greater than it's settled density. In other words when done correctly. Its not hard to do. That settled density is specified on the bag. Actual installed density can be calculated and verified at the time it is being installed with a little math.
> My method works very well at exceeding the settled density every time.


Don't doubt your method.
Can't see that it's worth the trouble
when the walls are already open. :blink:
Seems to waste time and labor $
to save on material ¢.
I must be confused....:laughing:


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## neolitic (Apr 20, 2006)

WarnerConstInc. said:


> Neo- I thought that too but, after having the blow-in blanket done a few times now the drywall always lays down smooth over the studs. There were a few spots that were 3/8" proud or the studs and no problems what so ever with the drywall. My neighbor (plumbing/HVAC/insulation) told me that it will not settle and that it is dense packed. Just relaying what I have seen, done and been told.
> 
> _He uses chopped fiberglass in thier system._


That might make a difference.

Just seems like a mighty fine line
between too fluffy and over filled
with the paper stuff.

No dog in this fight, really.


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## wheeler (Feb 8, 2009)

*cellulose if you can swing it*

cellulose will give you good coverage / r for the application and mice won't burrow / nest in it. expensive relative to vermiculite or perlit.


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## dlcj (Oct 1, 2007)

Im with MBS on this one. A friend of mine does work for the gov. insulating low income homes. He started dense packing walls couple years ago and uses about the same method mbs described. I was there on the first one and have helped out a few times sense. He pulls a piece of siding just above the bottom plate. Drills a 4" hole between every stud and uses a 1" id clear hose coupled to the 3" hose from the blower. Push it all the way to the top, pull back a couple inches and start the blow. When the blower stalls or you see the cell stop flowing in the clear hose pull down about 6" and do it again. Repeat till you pull the hose out the bottom. It makes little mess if you stop the blower at just the right time. He has a electric switch in hand to do this. when done use a piece of window flashing or metal to cover hole and reinstall siding. He has a vid on you tube titled wall blow i think.

On the other hand i agree with someone who said why do all that when the walls are open now. Foaming it would be the best but most expensive and wet set cell would be the next best imo. But from what you say about the low value of homes in the area and trying to save as much as possible, id just batt it and forget it.


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