Making Holes In My Walls

[T_Connor]

It's the only way I can figure to insulate my old house: to blow in cellulose insulation. But, before I go ahead and rent the hopper and buy those bags of old newspaper I have a question or three(five):

1) Anybody ever done this? Would you do it again at a different house?

2) Fire? Does blowing old recycled newspaper insulation into your walls turn them into instant match light 3000?

3) What do you do especially for outlets and fixture boxes? I've counted up and there are a total of 8 chases that include outlets, sconces, and switches that I would fill with this blown insulation. Should I do something special to keep the insulation free and clear of these guys (is it possible)? Is there a general rule-of-thumb for how close these receptacles can be to blown insulation?

Thanks for your time and helpful consideration. It's been said before, but it can't be said enough: you all are amazingly helpful. This forum reminds me of how my pop would go down to the Bank on Monday mornings and hang out with his old friends and ask questions like this...

Tim

[PastorPaul]

Tim,

I'm no expert on insulation, but it is my understanding that the cellulose is treated to be fire-resistant.

One thing to keep in mind when blowing in any insulation is to make sure you don't have fire blocking or other obstructions. Drill your hole at the top or bottom of the wall, then run a wire (a wire snake works well for this) into the cavity to make sure you can get all the way from the top to the bottom of the wall. If your wire won't go all the way, you have some type of obstruction.

Sometimes a good stud finder will locate fire blocking. Other times I have seen people drill their holes in both the top and bottom. The blow in from the top, and if the insulation is coming out the bottom they know they have a clear path. Plug the bottom hole and continue.

Another trick is to remove the baseboard and drill your holes behind it.That way your holes are hidden afterwards, without having to use spackling compound, joint tape, or whatever. Some people use only the baseboard to close the lower holes, but remember that anytime you have to remove the baseboard, you run the risk of having some of the insulation come out. Better to plug and cover over with the baseboard.

Pastor Paul
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[T_Connor]

Pastor Paul,

Thanks for the hints.

No fire blocking to worry about. Explored the wall cavities a lot recently with a rewiring project. Should be no problem to blow in the insulation.

Good to know about the fire-resistance treatment. I'll read over the product at the store this week, just to make sure.

On the baseboard front: done that already in one room. Not really an option in the others, as the walls suffer a bit much taking out the baseboard (they're 80 yr old plaster). I wonder about the ability of this insulation to blow all the way up a 9' wall though. My inclination would be to go at it from closer to the ceiling to ensure good fill...but it would be great to not have holes in two sets of walls!

I do still wonder about those receptacles...

Thanks,
Tim

[Lou_williams]

I have not done this so take this as a place to start to check it out.

I remember an This Old House where they had clapboard siding on the outside and removed a couple of board and dirlled from the outside. The major factor was the plaster walls and not wanting to risk the plaster damage. I hope that someone will give you some experience input.

[PastorPaul]

Now why didn't I think to suggest that? I've seen holes drilled in the siding before, but the plugs don't hide very well.

Pastor Paul
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[T_Connor]

I think I will cut holes in plaster. Taking off the siding is an idea, if I had any. I've got stucco. The veneer coat is hard and very, very brittle compared to the plaster. Plus, it is put on over old southern yellow pine plank siding. It took nearly half a day to cut out a hole for a front porch sconce. Therefore, hitting a few holes in the interior plaster is the way to go.

Perhaps the title was a bit misleading...I didn't mean to imply that my main problem was the future holes in my walls. That is not really the big issue for me. I've got swiss cheese holes as it is from the recent electrical rewiring work that I did. The issue that I really can't get my mind around is what to do in those chases where the is an outlet, switch, or jb...namely, do I attempt to build a box around the box to keep out the insulation? Is it necessary to keep insulation (cellulose) a minimum distance from a receptacle?

Thanks for your help, nonetheless!

Cheers,
Tim

[TDHofstetter]

I don't believe the receptacles or switches would pose any particular problems with blown-in insulation as long as it doesn't conduct electricity and doesn't get blown onto bare wire. Receptacles and switches shouldn't get hot - ever.

Lights, if they're recessed, will be an issue - but sconces should not. Again, you don't want to trap heat generated by a light within the wall - but sconces don't generate much heat within the wall.

-- Tim --


There is food enough for every bird.
It is seldom, however, thrown directly into the nest.

[Tom D]

You should check last time I inquired about this , they said fiberglass was availible to be blown in.

[bobleverton5]

Greetings,

I have blown in cellulose insulation numrous times. Typically we remove a siding board and blow from the exterior which cuts down on the mess significantly, but considering your stucco - I would say that the interior would be the route to go.

Cellulose down make a good insulation and it is fire retardant. It is safe to blow in sidewalls and will not pose a risk with electrical outlets and switches. In attic situations, you do want to be careful with can lights - or any fixture that puts off a lot of heat.

Blowing in insualtion is not a fool proof means of insulating exterior walls. We typically will inform the customer that around 80% of the wall will be insulated in spite of the most careful effort. Older houses tend to have areas of bizarre framing - not to mention blocks nailed occasionally between the studs. After filling a few cavities, you will know when a stud seems to fill up to fast. Plaster that has squeezed through the lath can block insulation from falling through, as can nails driven through the wall etc.

It is dusty and messy - so have some ventillation and wear a good dust mask.

Bob

[T_Connor]

Thanks everyone for the advice...

I'll sleep on this one.

Tim