Coverted Attic space above garage to Bedroom and ventilation problems

We are in the process of converting an attic space above garage and part of the loft above garage into a bedroom in Columbus, Ohio. It will be a cape cod style bedroom with 4 foot knee walls with storage behind it. The ceiling above is the roof. It is a side car load garage. The front of the room is the front of the house and that area is shaped like a triangle with the peak of the roof in the middle. There was one gable vent in there which is being replaced with a window. There are two soffit vents, one on each side of the bottom of triangle which would be on each side of front of house that faces the street (one is in the only overhang over the garage). The problem is that the sofit vents might get air to the first 2 to 3 bays that go up to the roof on each side of room and that is it. There is no ridge vent. There is no other air coming in.

We were going to insulate with R30 in ceilings and floors. I don't want to have to put in a ridge vent for three bays at most, maybe 3 feet. There is no where else to put soffit vents. What options to I have? The room is 10.8 to 4 foot knee walls and as you step out 1 foot, the pitch of ceiling goes up one foot. It is almost shaped like an upside down T. The front of house where the triangle shape roof is represents the bottom of T which is 10.8 wide 11.6 and if you follow up to top of T, to the left, I have small area 5.6 by 6 ft square where the roof comes down at a slant and the other side of T is a small closet.

My questions are:
1. Do I have to put in a ridge vent for only maybe three feet of ceiling rafters that are expose to the soffit vents?
2. Is there anything else I can do?
3. Do I have to have an airspace between insulation in roof sheeting if it's just dead air in most areas, no air coming in and none going out?
4. Do I have to have ventilation in there if the existing soffit vents are not providing much air?

Thanks for your help.

 

There will be more posts. I will get it started. Not seeing what you see, we may have a difficult time envisioning the exact problem, although you described it pretty well. Could you post a picture on a site like photobucket and give us the url?
This will help us answer #1
#3. R30 expands to 9 1/2", which is a 2x10, so I doubt you have that as rafters. You should allow air circulation between the insulation and the sheathing of the roof. This is accomplished by using the corrugated foam panels made by Owens Corning and others for this purpose. Of course this will cut down on the amount of insulation you can install. How wide are your ceiling rafter/joists?
#4. Yes you need more ventilation to make the area habitable. Once the pix are posted, we may be in a better position to give you a workaround.
Good luck, and we await your response.

 

Hi Larry,
I will try to post picture today or in the morning. The rafters were 2x6 and 2x8 and we made them into 2X10 through out the room. You say to use something called photobucket? What is that?

 

Photobucket.com is a picture posting medium. Post your pictures for free and give us the url in a post.

 

Hello,
I attached the url's to 4 pictures of the bedroom above garage. The shots that you see the gable vent covered in plast
where the window
is going to be are from the door going into bedroom. The shots where you see white banisters are from in the room looking outside to the existing loft. The knee walls are on each side of bedroom and the top of T is by the loft. The sofit vents are located on each side of gable vent behind the knee walls. The bottom of traingle.


There may be 3 bays that are exposed to light and air, so if you looked up at the rafters that we made 2X10 and followed those down behind knee wall to bottom where floor is going to be, that is where the soffit vent is located. That is the only area where there is air coming in. There are no ridge vents.

http://i30.photobucket.com/albums/c343/kaj3079/bedroomovergarage/extrabedrrom001.jpg

http://i30.photobucket.com/albums/c343/kaj3079/bedroomovergarage/extrabedrrom006.jpg

http://i30.photobucket.com/albums/c343/kaj3079/bedroomovergarage/extrabedrrom003.jpg

http://i30.photobucket.com/albums/c343/kaj3079/bedroomovergarage/extrabedrrom004.jpg

 

So far, it looks as if you have this thing whipped with the exception of the actual air movement. I understand the pictures of the inside of the attic, that you enlarged the rafters to 2x10. The thing I don't understand is why there are only 2 or 3 soffits that are exposed to the atomosphere. Maybe an exterior picture of the house showing the detail of where the soffits land will help. Once we get air to the bottom of the rafter run, all you will need to do is install air baffles all the way from the bottom to the top of the collar tie and install R25 over that, vapor barrier then wall/ceiling covering. The air will have to move from the bottom to the top and exit via a ridge vent, so there is more work to do on top.

 

Larry,
Here are some pictures of outside the house. The room is above side car garage. It is above the wreath. The gable vent that you see is where the window is going to be. The window on the side of garage is in my existing loft which is off bedroom. The two soffit vents that are part of that space are, #1 look at picture #4 where there is a small over hang over garage with the gutter. It is right there. The other one is located at the bottom of the triangle on the other side by the front porch where the gutter comes down. There are other vents that are over my front porch that should go up to the attic and on the other side of porch is another shaped triangle with another gable vent. There is a small space that runs from one side of house to the other over the front porch to the knee wall space in the room where are doing over. So there is a connecting walkway if you will that might be 12 inch by 12inch. Remember, the vents only vent air to maybe 2-3 rafters bays on each side of room, so I can't put a ridge vent acroos the whole roof of room if there is no air coming up from the other rafters, right? The storage area behind knee walls are going to be insulated and dry walled.




http://i30.photobucket.com/albums/c343/kaj3079/roomisinfrontofgouseabovewreath.jpg

http://i30.photobucket.com/albums/c343/kaj3079/outsidehousepictures005.jpg

http://i30.photobucket.com/albums/c343/kaj3079/outsidehousepictures002.jpg

http://i30.photobucket.com/albums/c343/kaj3079/lookatthispictoseeoverhangwithgutte.jpg

http://i30.photobucket.com/albums/c343/kaj3079/gableventwillbereaplcedwithwindow.jpg

 

A picture is really worth a thousand words. Now, the picture is clear as to your dilemma. You are only getting soffit ventilation from the front of the existing room. I know you said this in your posts, but my squirrelly mind couldn't comprehend it.
I hate to say it, but that's all you are going to get, since the roof lines oppose each other, and the other roof line has no soffiting. I would still do the baffle, insulation, ridge vent thing, because any air movement beats no air movement. As I said in an earlier post, I believe you are doing the right thing with what you have sofar. Good luck with the rest, and post back if we can help further.

 

Thanks Larry! So you think just having maybe 4 feet of ridge vent at the front of roof where the vents are Ok if only those 2-3 rafter cavities have air in them right? Would I still use a baffle or 1 inch air space in the insulation everywhere else even though there is no air movement in those rafters? Sorry for all the questions.