Cathedral Ceiling - Page 3

> > The kitchen of my house has a cathedral ceiling. The room is cold in
> > the winter and hot =A0in the summer. =A0The house was built in the late
> > 70s and I'm reasonably certain, there is little if any insulation
> > between the ceiling sheet rock and the roof. =A0 I can't get into the
> > area between the ceiling and roof to inspect. Any frost or light snow
> > on the kitchen roof =A0melts quickly whereas all the other areas of the
> > house with a flat ceiling and 13 inches of cellulose above, do not. =A0
> > I would like to insulate the ceiling from the inside and then install
> > either a suspended ceiling about 8 foot from the floor. I'm looking
> > for suggestions.

> Do you have any ceiling light fixtures in the kitchen? If so, you could
> turn off the power and remove the light fixture. This should let you see
> around the electrical box to see if there is insulation behind the
> sheetrock.
> You may also be able to measure up next to the electrical box to see how
> deep the rafters are. Standard R30 fiberglass insulation would need at
> least 2x12 joists (11-1/4" deep), though foam insulation may not need as
> much depth.
> This doesn't offer any "solution" to the problem, but at least you would
> know what is currently there.
> Anthony

> The kitchen of my house has a cathedral ceiling. The room is cold in the
> winter and hot =A0in the summer. =A0The house was built in the late 70s a=

> reasonably certain, there is little if any insulation between the ceiling
> sheet rock and the roof. =A0 I can't get into the area between the ceilin=

> roof to inspect. Any frost or light snow on the kitchen roof =A0melts qui=

> whereas all the other areas of the house with a flat ceiling and 13 inche=

> of cellulose above, do not. =A0 I would like to insulate the ceiling from=

> inside and then install either a suspended ceiling about 8 foot from the
> floor. I'm looking for suggestions.
> Thanks =A0John

> wrote:

> > The kitchen of my house has a cathedral ceiling. The room is cold in th=

> > winter and hot =A0in the summer. =A0The house was built in the late 70s=

> > reasonably certain, there is little if any insulation between the ceili=

> > sheet rock and the roof. =A0 I can't get into the area between the ceil=

> > roof to inspect. Any frost or light snow on the kitchen roof =A0melts q=

> > whereas all the other areas of the house with a flat ceiling and 13 inc=

> > of cellulose above, do not. =A0 I would like to insulate the ceiling fr=

> > inside and then install either a suspended ceiling about 8 foot from th=

> > floor. I'm looking for suggestions.
> > Thanks =A0John

> Cathedral ceilings are nice, to keep it restud over drywall on the
> studs then use foamboard, Polyisocyanutate Dow foilfaced is R 7.2 per
> inch with radiant barrier, its the highest R value insulation you can
> get. with 2x4 you will ger R 25.2, but thats not enough,2x6 will get
> you R 39.6, Finish anyway you want I use T&G pine planking

> > wrote:

> > > The kitchen of my house has a cathedral ceiling. The room is cold in =

> > > winter and hot =A0in the summer. =A0The house was built in the late 7=

> > > reasonably certain, there is little if any insulation between the cei=

> > > sheet rock and the roof. =A0 I can't get into the area between the ce=

> > > roof to inspect. Any frost or light snow on the kitchen roof =A0melts=

> > > whereas all the other areas of the house with a flat ceiling and 13 i=

> > > of cellulose above, do not. =A0 I would like to insulate the ceiling =

> > > inside and then install either a suspended ceiling about 8 foot from =

> > > floor. I'm looking for suggestions.
> > > Thanks =A0John

> > Cathedral ceilings are nice, to keep it restud over drywall on the
> > studs then use foamboard, Polyisocyanutate Dow foilfaced is R 7.2 per
> > inch with radiant barrier, its the highest R value insulation you can
> > get. with 2x4 you will ger R 25.2, but thats not enough,2x6 will get
> > you R 39.6, Finish anyway you want I use T&G pine planking

> I agree with this approach, with a slight variation and added details.
> 1 - if you have recessed lights in that ceiling, rip them out and seal
> up the holes. Recessed lights in cathedral ceilings should be illegal.
> They're a huge energy waster and worse, they are responsible for more
> moisture entry into the cavity than any amount of permeability of the
> ceiling material. If you do that, and close up any other holes in the
> ceiling, moisture will not be an issue in there.
> 2 - for optimal insulation, fill the cavities with dense packed
> cellulose. Forget what they're saying about ventilating under the roof
> deck. If you seal the holes, you don't need to worry about that. The
> only place moisture will get in the ceiling cavity during the winter
> is from indoors. You'll have less ice damming and better insulation
> all around if you just forget about it and seal up the cavity. For a
> typical 2x8 rafter, you'll get about R-25 insulation from the dense
> packed cellulose.
> 3 - Affix the foil faced polyiso board directly to the existing
> ceiling, 2" thick, taped at the seams Then, attach nailers over that,
> perpendicular to the original rafters. This will give you a high
> quality thermal break to minimize thermal bridging through the 2x4's.
> The foil faced polyiso board is also a complete vapor retarder, so
> this further ensures no moisture will get in the cavity. This will add
> R-15, bringing you up to R-40.
> 4 - If you want to go the extra mile, fill in the space between the
> 2x4's with another 1 1/2 of polyiso board, giving you another ~R10.
> Stagger the seams with the layer below, which again reduces any chance
> of moisture getting through the layers. Add sheetrock below, attached
> to the 2x4's.
> If you're afraid of filling the primary cavity because of the
> ventilation propaganda, leave it as is, but do the rest of the steps.
> But now you're going to want a total of 6+ inches of polyiso board in
> order to get sufficient insulation. This will be much more of a pain
> to install.
> Keep in mind that sheetrock is pretty cheap and easy to work with (for
> a pro), so don't be afraid to rip it out to get at the underside of
> the roof deck above. Another option besides the above one is to rip
> the ceiling out, then spray high density polyurethane directly to the
> roof deck above. Fill the cavities and seal up all the way down to the
> soffits. This will provide a complete vapor barrier and excellent
> insulation. No ventilation required or desired. when you're all done,
> this solution may be less expensive than the previous ones because
> it's just a couple steps - rip out ceiling, spray foam, replace
> ceiling.
> For more details on roofs, venting, etc., consult:http://www.buildingscie=

> You'll hear a lot of arguments about venting. Venting is needed when a
> structure is poorly built and it needs venting to remove the moisture
> carried by the warm, humid interior air leaking into the cavity. This
> warm air then cools, and when it does, the moisture condenses and rots
> out the roof. If you seal up the ceiling so that moisture can't get in
> there, the problem goes away. During the winter, when moisture is the
> big issue, the moisture must come from the inside. The outside air
> during the winter contains very little water, and will tend to
> dessicate the roof assembly rather than add to the moisture.
> During the summer, people will argue that venting is required to cool
> the roof. But the amount of cooling provided by venting in the normal
> fashion is vastly too small to actually be useful. Even a properly
> vented roof, with continuous strip vents at the soffits and large
> ridge vent provides minimal cooling, so that argument is bogus as
> well. The worst are the nominal vents that most people add - those
> 2"-3" holes drilled in the soffits and filled with "vents". The free
> area (amount of space open to allow air flow) is so tiny as to be
> totally worthless. Worse, during the winter, south facing walls heat
> up and the warm air from the walls will travel up and into the soffit
> vents. This then warms the roof, melting the snow and leads to ice
> dams. Current building practices are a series of band aids applied to
> fix other problems. If it were done right in the first place, with
> proper consideration for the physics involved, these problems would go
> away.