Not sure what the code is on that, but I think it has to be secured every 4 foot when ran along the bottom of a joist or rafter, and it needs to be stapled with in 8 inches of the box. I always just ran it across the floor of the attic and stapled it every so often, less wire used that way to. They make flexible stuff like your talking, but if you want it 3 inches, not sure it comes that way. And the flexible stuff i have seen has all been for low voltage wiring, phones, cable. I would use 3 inch pvc pipe. Put some kind of seal over the end to prevent air leaking from the basement out in to the attic, or little critters finding their way down. My parents have a 1926 ballooned framed house, and all the fiberglass blown in insulation has settled down, so there is no insulation on the second story. The guy that is coming to do my spray foam, also does cellulose, I will find out from him if it settles like fiberglass. I need insulation between my brick and plaster wall as well, but I only have about 1 to 1 and 1/2 inch air gap there. When I insulate that, I will do it from the inside, then just put up 1/4 drywall over the wall and have it finished and textured like the drywall work that I am getting done here soon. I will probably use a low expanding closed cell spray foam for that, but that will have to be a DIY project. Michael
_____ From: [email protected] [mailto:[email protected]] On Behalf Of Dan Rossi Sent: Monday, September 14, 2009 10:05 AM To: [email protected] Subject: Re: [BlindHandyMan] spray insilation question. I am planning on having cellulose blown in sometime in the near future. They said they can use a 3/4 inch nozzle since they will have to drill through the mortar joints they want to use as small a nozzle as possible. Not only do they have to drill through the mortar joints, but then they have to drill through the wood cladding beyond the airgap behind the brick to get to the voids between the studs. I may hold off on having the attic done until I do some rewiring first. I'd rather not have to dig through 12 inches of cellulose to get to all the fixtures. Here is a vague plan, and a couple of questions. My house is balloon construction, so the joist bays run from the attic straight down to the basement. I've already pulled one set of wires from the second floor through to the basement. Anyway, I was thinking of trying to find some 3 inch flexible tubing, similar to the 4 inch flexible pipe I used for drainage around the basement door well. I would run this flexible tubing down from the attic to the basement in one or two places before having the insulation blown in, that way I would have a wire chase in place for future wiring projects. Does this kind of flexible tubing exist? Is there a reason why I wouldn't want to do this? Secondly, what is the code for running wiring through attics with blown in insulation? It seems like it would be a total pain in the ass to just bury the wiring under the insulation. Can you staple the wiring to the sloping rafters and then drop straight down from the rafter to the fixture in the ceiling below? It would make it quite obvious where the fixtures are, and you could easily see the wiring, but there would be these vertical wires scattered around your attic. Is that cosher? -- Blue skies. Dan Rossi Carnegie Mellon University. E-Mail: d...@andrew. <mailto:dr25%40andrew.cmu.edu> cmu.edu Tel: (412) 268-9081 [Non-text portions of this message have been removed]
