Ceiling Insulation HELP?

[Unregistered]

I am currently remodeling the upstairs of my cape.


the ceiling was made of 12" ceiling tiles stapled to 1x3's that were nailed to the joists, i ripped off all the tiles.

i gutted all the walls and installed new fiberglass insulation in the walls.

well since, i have been trying to redo all the electrical in the ceiling, but working in the ceiling doing electrical is rediculous.

they had insulation placed up in between the rafters with i beleive cellulous laying on top of that insulation. the insulation is all deteriorating, and when you try to work around it, it breaks, falls, and is VERY messy.

I am planning on ripping all that insulation rolls/cellulose down, while wearing a mask and goggles.

my question is:

i plan on placing THICK rolls of fiberglass insulation between the joists, but where will i place all the new electrical wires? below the insualtion or above it?
please help, this is gonna be a very messy job.....i am not sure what do do first, the ceiling electrical work or the ceiling insulation work?

[Unregistered]

Instead of running full batts, cut the runs beyond the wiring 6" -12". Then peel the insulation back as far as needed to get past the wiring. In other words, your splitting the insulation so some goes over and some goes behind the wiring. Butt up to it with the remaining piece needed to complete the run. Your trying not to compress the fiberglass and this is the way to do it. Do your best to snog up your vapor barrier at the cut.

ALSO, be sure to not insulate right up to the back of the roof deck. You can trap moisture and rot the roof deck. You want to leave at least an inch or so of air space between the insulation and the bottom of the roof deck. This includes where the flat ceiling meets the slope, and the slope meets the sidewall. A good way to ensure you maintain this airspace is to staple venting baffles to the bottom of the roof deck on the slope portion, before insulating. If this needed airspace means you cannot put as much fiberglass in without compressing it and sacrificing r-value, an option is to fir the slopes out woth 2"x2"'s to gain the extra space. Foil faced insulation is another option for the slopes in that as long as you maintain, i believe a 3/8" inch airspace between ti and the back of the drywall, you gain an extra R-2.
Ex. R-11 FOIL installed properly, stappled between the rafters, will give you more like an R-13. If you face staple it of stuff to much into a cavity that wont accomodate it, you will lose that 3/8" space needed between the foil and the back of the drywall that gives you the additional R-2.

[Unregistered]

Instead of running full batts, cut the runs beyond the wiring 6" -12". Then peel the insulation back as far as needed to get past the wiring. In other words, your splitting the insulation so some goes over and some goes behind the wiring. Butt up to it with the remaining piece needed to complete the run. Your trying not to compress the fiberglass and this is the way to do it. Do your best to snog up your vapor barrier at the cut.

ALSO, be sure to not insulate right up to the back of the roof deck. You can trap moisture and rot the roof deck. You want to leave at least an inch or so of air space between the insulation and the bottom of the roof deck. This includes where the flat ceiling meets the slope, and the slope meets the sidewall. A good way to ensure you maintain this airspace is to staple venting baffles to the bottom of the roof deck on the slope portion, before insulating. If this needed airspace means you cannot put as much fiberglass in without compressing it and sacrificing r-value, an option is to fir the slopes out woth 2"x2"'s to gain the extra space. Foil faced insulation is another option for the slopes in that as long as you maintain, i believe a 3/8" inch airspace between ti and the back of the drywall, you gain an extra R-2.
Ex. R-11 FOIL installed properly, stappled between the rafters, will give you more like an R-13. If you face staple it of stuff to much into a cavity that wont accomodate it, you will lose that 3/8" space needed between the foil and the back of the drywall that gives you the additional R-2.

i am not exactly sure of what you mean by:

Instead of running full batts, cut the runs beyond the wiring 6" -12". Then peel the insulation back as far as needed to get past the wiring. In other words, your splitting the insulation so some goes over and some goes behind the wiring. Butt up to it with the remaining piece needed to complete the run.

i am planning on putting 12" of insulation up there.

[Unregistered]

Meaning instead of running the full length of the slope with 1 piece, cut it length-wise near the point where the wiring goes through the joists. If your using R-30, i assume it comes in 4 ft. batts. This makes it easier. If your wires pass through the joists at say 2 ft. from the bottom of the slope, just peel the insulation back to the point you need, depending on the depth the wiring runs. Say the batt is approx. 10" and the wiring runs approx. mid way through the rafter. Peel it back depth wise approx. 1/2 way to get 1/2 behind and 1/2 in front of the wire. You don't need to peel the whole piece, just enough to get around the wire. This way you remove no insulation and loose no R- value. Your temporartily peeling it to get behind and in front of the wires. Peeling it 1/2 way means 1 of the halves will have the vapor barrier and the other won't. Do't need to peel the whole 4 ft., just enough to get behind the wires. ****Be sure to have an airspace behind the insulation and under the roof deck! (Or your roof deck can rot out from trapped moisture.) Fir the slopes out w/ 2"x2" 's if you need the extra space to allow for this air flow to in a cape is probaly a gable vent. I'm going to work. Please be sure you understand before you start. You can run into alot of trouble with these. I've seen large sections of these tongue and groove roof decks rotted out from improper installations. I'll check in later...

[Unregistered]

Meaning instead of running the full length of the slope with 1 piece, cut it length-wise near the point where the wiring goes through the joists. If your using R-30, i assume it comes in 4 ft. batts. This makes it easier. If your wires pass through the joists at say 2 ft. from the bottom of the slope, just peel the insulation back to the point you need, depending on the depth the wiring runs. Say the batt is approx. 10" and the wiring runs approx. mid way through the rafter. Peel it back depth wise approx. 1/2 way to get 1/2 behind and 1/2 in front of the wire. You don't need to peel the whole piece, just enough to get around the wire. This way you remove no insulation and loose no R- value. Your temporartily peeling it to get behind and in front of the wires. Peeling it 1/2 way means 1 of the halves will have the vapor barrier and the other won't. Do't need to peel the whole 4 ft., just enough to get behind the wires. ****Be sure to have an airspace behind the insulation and under the roof deck! (Or your roof deck can rot out from trapped moisture.) Fir the slopes out w/ 2"x2" 's if you need the extra space to allow for this air flow to in a cape is probaly a gable vent. I'm going to work. Please be sure you understand before you start. You can run into alot of trouble with these. I've seen large sections of these tongue and groove roof decks rotted out from improper installations. I'll check in later...

ok, i think i undertsnad. i believe i will use r-38 rolls of insulation, 12" thick i believe.

i take it i do all my electrical wiring first, then insulate after.
shoudnt most wiring be done in the middle of the joists?
what you are saying cut the batts the long way and have some below the wiring and some laying on top so after i get all the ceilign full of insulation, if i stand below and look up, i should not be able to see any of the wiring except the wiring hanging down for lights, correct?

couldnt i install baffles up on the dormer ceiling slope so the insulation does not hit the roof top?

thanks.

[Unregistered]

i think i am having 2nd thoughts of taking it all down, i made a holle today and looked up above and it is all filled with cellulose above the ceiling, so i think i am gonna leave it how it is, maybe fill in some places where insulation fell away, and install a new ceiling.

[Wgoodrich]

Fastest easiest way to accomplish what you were thinking is to strip off the ceiling and old insulation opening the ceiling to open joists.

Do you wiring and heating and plumbing. Then install the styrofoam shutes between the rafters about 1 foot long in between each rafter where the wall meats that rafter to ensure open air flow from soffitt into attic for air circulation protecting your roof decking from moisture. Then nail a plastic bisquine sheeting to the bottom of the ceiling joists. Then drywall. Then rent a cellulous fiber or fiberglass insulation blower and blow in insulation following manufacturer installation instructions on the package to meet the required R value of your area in the attic. You are done.

If you leave the old insulation etc. you leave all mistakes and deteriated material limiting the value of your whole house remodel. Do the above it is easy normal construction methods and you can sell the house claiming up that the home was brought up to new standards at time of whole house remodling showing great savings in engergy costs.

Good Luck

Wg