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cheese9988 03-05-2010 11:40 PM

Blown insulation questions

I am not exactly sure what forum this would fall under...I guess it is remodeling.

Anyway. I plan on using this years tax refund to insulate the house, and then take advantage of the tax credits.

For some info...I have a large older house in Rochester NY, in the city. The house was built somewhere between 1910 and 1920 and is in pretty good shape. The house has the old asbestos siding, so I can pop the siding off and blow the insulation in from the outside. My wife and I plan on staying here for awhile, and the heat bills are high. I have been reading information off and on for a year now and there are some general questions that I can't find.

1. I need to know the stud spacing of a house this old. Obviously I need to know where to make my holes.

2. I know it makes a mess, but how much? The houses are close together, and I am sure they won't want the stuff blowing in their yard.

3. My plan is to do the bottom floor first, then do the second floor. Just in case there is some kind of spacer between the two floors. The attic has been converted to a loft and is insulated already. I have read some info about having to feed the hose through the wall to make sure it gets filled up. I can't just blow it in from the hole? Are the hoses long enough to do this from the second story?

4. Does the celluse (spelling) settle? I have read alot of conflicting information. Some say it does, some say it doesn't or it takes a considerable amount of time. I don't know if they are talking about an older product or not. Obviously if it has settled, the insulation was put in at least a decade ago.

Scuba_Dave 03-06-2010 08:43 AM

I haven't done this but a few points I have read:

Cost of hiring someone was not that much more VS DIY when someone checked into prices

Stud spacing is usually 16"...but that can last house from 1905 was 16" OC

The machines from big box stores (I have heard) are not as powerful as the mchines that the Pro's use

It may settle, more powerful blower wil pack it in better which will help prevent settling

Daniel Holzman 03-06-2010 09:09 AM

Ditto Scuba. I considered installing cellulose myself in my house, but rejected the idea of DIY for three reasons:

1. Time factor. Takes a lot longer to do walls than you might think. On a two story house like mine, you have to set up ladders, drill holes etc., which introduces a danger element I did not want to deal with.

2. Cost. When I checked out all the costs, it was no more expensive to hire a contractor than DIY, plus they actually know what they are doing, versus I would be learning on the job.

3. Machine availability. In order to pack cellulose tight enough to resist settling, you need a blower that is considerably higher pressure than the typical big box store rental unit. Those units are designed to installing cellulose into an attic, not a wall. The contractor I hired had a large, powerful 240 volt contractor grade blower that was not available from any rental store I checked with. Not saying you can't rent it, but do not attempt to do walls with a low power blower, you will not get satisfactory results.

Conclusion: Blown cellulose in walls does not make DIY sense. This is a job best left to an experienced contractor.

cheese9988 03-06-2010 11:06 AM

Well....that really didn't answer all of my questions. But thanks for the advise. I have looked into cost, and it will be cheaper for me to do it on my own. I have other improvements that I have to consider this year too.

Scuba_Dave 03-06-2010 12:00 PM

Stud spacing should be 16" but that will vary depending upon windows, doors, modifications to original building, and the original builder
I have seen some older homes 20" on center

In addition my house has diagonal braces at the corners
So in some cases you will need to drill multiple holes in each stud bay to fill all cavities

Yes it will blow around & make some of a mess
How much depends upon you & your install method

Yes, with the low power unit there will (eventually) be quite a bit of settling
In addition with the lower powered rental unit it will not pack as tightly & insulating value will be less
If you can find a high power unit that is your best bet

No you can't just blow it in the hole...that area will fill up & the rest won't
So there is a method to this that takes some skill
They showed on HGTV a Pro filling a cavity with a plexiglass front
He raised the hose as he filled

You will need to verify with the people you are renting the equipment from on hose length & if you will have enough to reach where you want

Gary in WA 03-06-2010 01:32 PM

Be safe, Gary

cheese9988 03-06-2010 06:41 PM

Great, that answers my questions! :thumbsup:

The PDF is nice too. I have the old asbestos shingles, I am thinking their removal will be the most difficult part. They crack so easy, good thing I have some extras and color matched paint. The PDF gave some good advise.

tpolk 03-06-2010 06:57 PM

old framing layout with full size lumber used to be 19"oc. getting ready to soffit a house with this layout. scuba is right expect diagonal bracing in each corner minimum depending on length of wall. those are asbestos shingles most likely for siding. take care with the dusting of them. I would also tape off wall penetrations on the inside, outlets, switches, sconces etc

cheese9988 03-07-2010 10:26 AM


Originally Posted by tpolk (Post 410770)
old framing layout with full size lumber used to be 19"oc. getting ready to soffit a house with this layout. scuba is right expect diagonal bracing in each corner minimum depending on length of wall. those are asbestos shingles most likely for siding. take care with the dusting of them. I would also tape off wall penetrations on the inside, outlets, switches, sconces etc

I may have to look into the stud spacing. I want to be 100% sure before I start drilling holes. There are a couple outlets where the air just blows right past them, I'll get some masking tape. I gotta imagine with stuff like this, even if the insulation did settle a little, it is still going to be a heck of a lot better than what it was. The outlets and cracks under the molding shoot out air all winter...some clear caulk does help.

Gary in WA 03-07-2010 11:19 AM

Seal the outlets on the inside holes with canned foam, IF not knob and tube wiring. (Do not bury K&T with insulation for heat build-up). pp. 72- that modern development- balloon framing, pp. 78, 81, 83, 89- all standard around here:
Also of interest in your case:

Be sure to get a balanced attic venting system with your older balloon framed.

Be safe, Gary

cheese9988 03-07-2010 12:31 PM

In the case of electrical, I got lucky. All the knob and tube has been replaced. Most of the house has pipe attached to each electrical box, I think they call it raceway now. So it has actually made it easy to replace the wiring. Right now, the wiring is a mix of BX, cloth romex and modern romex wiring. I have been slowly replacing the cloth wiring, the cloth seems to be brittle, so I replace it whenever I touch it. The house has breakers too.

The attic has been converted to a loft, is fully insulated and ventilated. Everything is drywall and Spackled, the ceiling is vented at the roof. The windows are so-so, I will fix them at some point.

cheese9988 03-07-2010 03:16 PM

Been crunching numbers and reading all afternoon. The house has little insulation. The 3rd floor family room, the side hallway and the bathroom are the only insulated rooms. The kitchen will be gutted at some point, so no sense there.

I measured and I estimate that there is 1100 sqft of hollow wall to insulate. Home depot sells the blown in insulation at $ 10.76 a bag that covers 40 sqft. That comes out to roughly $300 to insulate the house, we get 30 % on our taxes next year, that comes out to $90. If we buy 20 bags of insulation, we can rent the hopper for free.

I have read energy savings estimated from 5 % in Raleigh to 50 % in Boston from various internet sources. So if I shoot for at least a 25% savings it will take one year to pay itself off. And save a butt load of money in the long run, not to mention the wear and tear on the furnace.

The cheapest I have found so far to have someone install is $ 0.99 a sqft, thats over three times the cost. I think I'll do it myself as usual.

cheese9988 09-10-2010 03:15 PM

I posted this stuff awhile ago. So I'd like to share how everything went.

It took us 3 1/2 days, with three people. For our house, probably around 20 bags of insulation all together. For the project, misc supplies, hole cutting bits, insulation, food, etc we probably spent closer to $400.

The third person taped over every light switch and outlet in the house, got food and supplies.

We had one person removing the siding shingles, another drilling holes. We drilled two holes for each section, one for the hopper, one to let the air out. You WILL need a strong two handed drill, if you hit a stud, it WILL kick back and bruise your wrists. One line of holes on the 1st and one on the 2nd floor. Holes under every window or over hang. The third person was needed after shingles were all removed to feed the hopper, drilling holes takes longer. The hole drilling was by far the most difficult and time consuming part, it was a hot summer on top of that. We have no shade on the south side of the house.

The hopper is easy to operate, it requires one on the ladder, one next to the hopper continuously feeding. It helps if both have eye contact. We found it best if you really broke up the insulation as small as possible. It fed much nicer that way. After a few holes, you get a feel for the machine, you can tell when the hole gets full just by the force of the air. The hose gets heavy, especially up two stories. We did the first floor then the 2nd, to make sure everything would be packed as best as possible.

It definitely filled up the nooks and crannies. Even though everything we could find was taped, the insulation still found and plugged up holes we never even knew were there. Even in weird spots, like the basement, I can see some of it came out. There was a hole we forgot to drill on the first floor, and did the 2nd floor above it. After drilling the hole we forgot, it was apparent that the area was already filled, so it does a good job. Also, the insulation makes a huge mess of the yard, so have brooms and trash-bags ready to clean the stuff up.

And pushing the hose into the wall, and pulling it out slowly, this was impossible for us. The hose had too large a diameter and simply would not fit in the wall cavity. Others who we talked to, had the same problem, but had satisfactory results anyway. With the stuff coming out holes in the house, I am confident that it did a good job filling. With the holes already drilled, We could even add more insulation in ten years if we wanted, most of the work is done.

All in all, there were well over 100 holes to drill. It was a tremendous amount of work, but we estimate it saved us $800 to $1000 in labor costs. I think that was worth it. If I did it all over again, I would get two more people to help with the hole drilling.

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