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Attic Insulation/Rafter Vents/Frames blocking ventilation

Attic Insulation/Rafter Vents/Frames blocking ventilation


Old 02-22-09, 09:07 AM
Thread Starter
Join Date: Feb 2009
Location: Carrollton, VA
Posts: 4
Attic Insulation/Rafter Vents/Frames blocking ventilation

I am adding insulation to my home in Hampton Roads area of VA. It was built 2006. I have several attic spaces and the one above my bedroom has blown in floor insulation. I had a contractor here and he said it meets code.

I have soffit vents and a roof ridge vent.

However, my bedroom is cold in the winter and hot in the summer. So, I plan on adding R-38 to the roof ceiling in the aqttic space above my room. My rafters are 16" on center.

I have a uniquely shaped bedroom and the rafters don't all go to the peak at every location. Some of them terminate at a cross member. In essence this blocks the air flow from the soffit to the ridge. The cross member is associated with the support for other roof lines on the main part of my house.

I want to install R-38 in conjunction with the foam ventilation baffles however, how do I ensure proper ventilation in these locations?

I have considered drilling holes in the cross member where the baffle will terminate so air can flow through to the next baffle and up to the ridge vent. I have also considered installing an attic fan.

What is the proper/best and to code method of handling this?

Thanks many. I can email pictures if I haven't described my situation clearly.
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Old 02-22-09, 09:36 AM
Join Date: Oct 2008
Location: New England
Posts: 9,995
Hi Tony and welcome to the board, you can post your pictures to photobucket.com and post the link over here. Pictures help.

Also describe what you have for windows, wall insulation and floors and foundation. Any recessed lights into the attic, gaps aroung chimneys or plumbing. What is your heating/cooling system?

Old 02-22-09, 10:29 AM
Thread Starter
Join Date: Feb 2009
Location: Carrollton, VA
Posts: 4
Thanks Bud...

I will get going on the pictures..

My house is a two story, brick front, vinyl siding on the sides and back. I have a brick skirt with slide vents and a 3-4 foot crawl space.The 1st floor has wood and tile floors.

My bedroom is on the first floor. The attic space above my room is accessed from a bedroom on the second floor. This attic is completely on the second floor - no stairs to go up higher. First go into a closet then open another door to the attic.

My bedroom has probably 10-12 canned lights, a ceiling fan, and a few other light fixtures.

In the middle of the house there is another, very large, attic space - 3rd floor. This is uninsulated.

The interior walls on the attic I want to insulate have Johns Manville R-19 and the floor has about 16" of blown in loose insulation. The installer put a foam baffle plate all the way around the base to prevent the wind from blowing the insulation.

The red arrow shows the direction of the soffit. The other picture shows a ridge vent for one rafter run and the left side doesn't have one - not because the builder did it wrong. I'll add some pictures in a few minutes.

Old 02-22-09, 10:48 AM
Thread Starter
Join Date: Feb 2009
Location: Carrollton, VA
Posts: 4
HVAC - 2 zones central - Natural Gas.
Windows - 2 pane builder grade. Not the best for energy, but not the worst.
No masonry chimney - just ventless gas fireplass.
No real gaps around any fixture, the blown in insulation covers everything.
Here are some more pictures:
Here is a view of the turret roof:

Here is a view of one of the problem areas - blocked access to the ridge vent:

Here is a view of area with no soffit vent but a ridge vent:

Here is a vew of a good run - I have started the foam baffle install. I could use some advice - do I need to connect these baffles together or leave a gap between multiple baffles?

Old 02-22-09, 11:18 AM
Join Date: Feb 2009
Posts: 2
putting insulation on the underside of a roof on an unfinished attic is useless, u have ventilation coming in from the soffit and ridgevent so your just insulating between vented attic space and the outside?
It appears u have 4-6 inches of insulation in your attic, based on where you are located you should have around 10". also your boxes and things in your attic is compressing your fiberglass making it less effective i would reccomend creating somekind of cheap shelf high enough that its above the level of insulation and sturdy enough to keep your belongings off the rafters.
Old 02-22-09, 12:27 PM
Thread Starter
Join Date: Feb 2009
Location: Carrollton, VA
Posts: 4
That one picture does make it look like I have stuff on the blown in insulation. I actually have a floor board that stuff is sitting on.

Trust me, I would rather not do this. But, after almost three years of hot summers and cold winters in my bedroom - my wife and I decided we will try insulating.

Is it required to install rafter vents where there is no soffit at the bottom - but a ridge vent at the top? It can't hurt and those things are cheap.
Old 02-22-09, 08:10 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,399
The better you can seal and insulate the living spaces from the attic the better for your heating and cooling costs. The better you can ventilate the attic spaces the better for your roof deck (both inside and out) and the finished roofing material. Part of the reason to ventilate the attic is to remove any water vapor that enters the attic from the living spaces.

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