Attic insulation

[bcope]

I have a 2 1/2 story house. There is no isulation in the walls or attic. The attic is finished. How can I put insulation in the ceiling and still allow for ventelaiton at the roof. I would like to blow cellulose in the walls and celing. but I don't know if I can blow it in the celing. What is my best option for the finished attic?

[bcope]

No one has any advice?

[pushkins]

Youcan certainly blow in insulation to the walls without too many problems.
From the description you have given in regards to your ceiling it is a whole new problem.
What you need to avoid in the ceiling is contact of the insulation to the drywall and the ply/sheathing of the roof. Blowing in cellulose into the ceiling will most definately not be the best option.
Does you roof have ridge venting of cap vents?

[bcope]

yes, there are is a vent along the ridge and the cap.

[pushkins]

Unfortunately I don't have any great news for you in regards to the ceiling.
Having a ridge vent makes the purpose of insulation much easier to achieve and install correctly.
The only way I can see that you can correctly add insulation to your ceiling is to remove the drywall ceiling sheets, add an insulation seperator (keeps the insulation from touching the underside of the roof) install the batt insulation and then rehang the drywall.
What you must avoid is insulation being jammed between the ceiling and the roof if that happens you will stop most of the airflow and aid in premature shingle problems.

[Ironman1079]

aid in premature shingle problems.

what type of shingle problems would this be?

thanks.

jr

[pushkins]

The most noteable one is premature curling. The heat gets trapped hard against the ply (mainly because of no air flow).

[Ironman1079]

i have noticed some peoples roof get black stain looking marks running up the house in certain areas, what causes this?

[pushkins]

I'm not sure I understand your question ?

[Wgoodrich]

Look where the black stain runs are. I suspect you will find a gutter down spout there. Many times the sap of trees and leaves leave a stain when running down a concentrated area of a roof.

Wg

[Ironman1079]

Look where the black stain runs are. I suspect you will find a gutter down spout there. Many times the sap of trees and leaves leave a stain when running down a concentrated area of a roof.

Wg

sorry chief, no gutter downspouts at these areas and no trees above these roof areas, actually there is nothing above this neighbors roof except blue sky of course.

[Guest]

i have noticed some peoples roof get black stain looking marks running up the house in certain areas, what causes this?
Usually the black streaks are on the north side and it is mold. It can be cleaned off (power washed or bleached 20% with 80%H2O). The newer fiberglass based shingles are more prone to mold that the old ashalt type.

[Under_Miner]

i have noticed some peoples roof get black stain looking marks running up the house in certain areas, what causes this?
These stains or streaks can also be the result of a steep roof and the pebbles are releasing from the tar on the shingles revealing the black lower layer of the shingles. This typically occurs in steeper roofs which can shorten the life span of the shingles. Check the gutters and down-spout discharge areas, you should find some colored grit near or in these areas, that is what is coming off the shingles. Wait just after a rainfall and these "black stains" are more noticeable, that is a sign that the grains are coming off the shingles as a result of the rain.