Insulation, Radiant and Vapor Barriers - Add Air Intake vents to roof of 1920 house??: See PIX
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dvarga
05-24-09, 10:12 AM
I have a 1920's clapboard house. My question is how to get outside air into the knee wall space which will be the intake air for the attic fan.
The third floor has a peaked roof. It is a finished space with knee walls and air channels that link the the knee wall spaces and the very peak of the roof (a triangular area at the very top that I can crawl around in. This top most area has a strong fan and output vent. Right now the only 'intake' air would be when I open the hatch from the third floor to this top area. I want to make it so that the fan can pull not only the air through the hatch, but also circulate fresh air and cool the entire roof.
Here are the ways I that I figure I could do it. Add intake vents:
Louvers installed in the clapboard of the knee wall areas (messing with the integrity of the clapboard, and visually not looking good)
Roof vents that allow air into the kneewall area (messing with the integrity of the roof!)
Drilling 1.5" holes through this wood at the junction of the roof and the floor of the third floor
Maybe there is another way?
It appears that this third option there might be a cross member on the inside and another one on the outside to drill through? If I drilled through both, I would have to put in screen to keep out birds, bats and bees. Is this crazy to do this one?
I check around this area, very few houses like mine have any intake for the attic. There are no soffit areas to access like what new houses have.
See pictures: Untitled Document (http://www.netdevi.com/hse/intake.htm)
The third floor has a peaked roof. It is a finished space with knee walls and air channels that link the the knee wall spaces and the very peak of the roof (a triangular area at the very top that I can crawl around in. This top most area has a strong fan and output vent. Right now the only 'intake' air would be when I open the hatch from the third floor to this top area. I want to make it so that the fan can pull not only the air through the hatch, but also circulate fresh air and cool the entire roof.
Here are the ways I that I figure I could do it. Add intake vents:
Louvers installed in the clapboard of the knee wall areas (messing with the integrity of the clapboard, and visually not looking good)
Roof vents that allow air into the kneewall area (messing with the integrity of the roof!)
Drilling 1.5" holes through this wood at the junction of the roof and the floor of the third floor
Maybe there is another way?
It appears that this third option there might be a cross member on the inside and another one on the outside to drill through? If I drilled through both, I would have to put in screen to keep out birds, bats and bees. Is this crazy to do this one?
I check around this area, very few houses like mine have any intake for the attic. There are no soffit areas to access like what new houses have.
See pictures: Untitled Document (http://www.netdevi.com/hse/intake.htm)
diyplank
05-25-09, 09:16 PM
I kinda went through the same thing w/ my attached 1 car garage. I wanted to install insulation in the ceiling between the rafters so I could use it in the winter. We both have the same kinda houses. Siding is the same on mine as well. Built in the 40's. No finished attic for me though. Atleast not yet.
So to get this straight you have a roof fan/vent and you wanna install other vents to allow more air to circulate?
Well option 3 probably one of the best. Now structurally, I am not sure. I don't see why it would hurt though!! You will need an architect/contractor for this part. The 2x4's look like they are just nailed in between the rafters and to separate the outside from the inside. I have seen these little vents at lowes. Not sure if these are the same ones though. They are just 2" round louvered tin/aluminum vents correct??
The possible 4th option would be to have someone come in and install a ridge vent. Not sure if this is possible either since you have half the attic finished. Can you get to the peak w/o messing w/ the finished space?
Possible 5th would be have someone/or yourself box in your roof over hang to you can install soffit vents!!
Kinda expensive for the last 2 options that I suggested.
Hope I helped a little since no else posted. Hopefully more people chime in.
Keep us posted.
So to get this straight you have a roof fan/vent and you wanna install other vents to allow more air to circulate?
Well option 3 probably one of the best. Now structurally, I am not sure. I don't see why it would hurt though!! You will need an architect/contractor for this part. The 2x4's look like they are just nailed in between the rafters and to separate the outside from the inside. I have seen these little vents at lowes. Not sure if these are the same ones though. They are just 2" round louvered tin/aluminum vents correct??
The possible 4th option would be to have someone come in and install a ridge vent. Not sure if this is possible either since you have half the attic finished. Can you get to the peak w/o messing w/ the finished space?
Possible 5th would be have someone/or yourself box in your roof over hang to you can install soffit vents!!
Kinda expensive for the last 2 options that I suggested.
Hope I helped a little since no else posted. Hopefully more people chime in.
Keep us posted.
GBR in WA
05-25-09, 09:50 PM
The blocks at soffit are square (inside ones) and plumb (outside ones). It appears the are next to one another, back to back. Drilling and screening the outsides would be very difficult (3-2"holes in each). I would go with these at the start of the attic near the exterior wall:
Cor-A-Vent : IN-Vent (http://www.cor-a-vent.com/in-vent.cfm) and install a good ridge vent. The clear vent area is variable on different brands.
A good read for the volume required:
Attic Ventilation (http://www.cornerstoneinspectionsdfw.com/Attic_Ventilation.html)
Be safe, G
Cor-A-Vent : IN-Vent (http://www.cor-a-vent.com/in-vent.cfm) and install a good ridge vent. The clear vent area is variable on different brands.
A good read for the volume required:
Attic Ventilation (http://www.cornerstoneinspectionsdfw.com/Attic_Ventilation.html)
Be safe, G
dvarga
05-26-09, 05:54 PM
DIYPLANK,
So to get this straight you have a roof fan/vent and you wanna install other vents to allow more air to circulate?
>> Yes, have the output vent with fan. Need the air inputs in the bottom of the roof area.
Well option 3 probably one of the best. Now structurally, I am not sure. I don't see why it would hurt though!! You will need an architect/contractor for this part. The 2x4's look like they are just nailed in between the rafters and to separate the outside from the inside. I have seen these little vents at lowes. Not sure if these are the same ones though. They are just 2" round louvered tin/aluminum vents correct??
>>I was thinking to keep the cross 2x4 there, just drill through it, a couple of holes, each 1.5 or 2", drill to the outside. Then fashion a screen to stop bugs and such from slipping in. I can easily create something and apply it from the inside, for the outside.
The possible 4th option would be to have someone come in and install a ridge vent. Not sure if this is possible either since you have half the attic finished. Can you get to the peak w/o messing w/ the finished space?
>>I can get to 1/2 of the peak without messing with the finished space.
Thx.. for your thoughts.
Dave
So to get this straight you have a roof fan/vent and you wanna install other vents to allow more air to circulate?
>> Yes, have the output vent with fan. Need the air inputs in the bottom of the roof area.
Well option 3 probably one of the best. Now structurally, I am not sure. I don't see why it would hurt though!! You will need an architect/contractor for this part. The 2x4's look like they are just nailed in between the rafters and to separate the outside from the inside. I have seen these little vents at lowes. Not sure if these are the same ones though. They are just 2" round louvered tin/aluminum vents correct??
>>I was thinking to keep the cross 2x4 there, just drill through it, a couple of holes, each 1.5 or 2", drill to the outside. Then fashion a screen to stop bugs and such from slipping in. I can easily create something and apply it from the inside, for the outside.
The possible 4th option would be to have someone come in and install a ridge vent. Not sure if this is possible either since you have half the attic finished. Can you get to the peak w/o messing w/ the finished space?
>>I can get to 1/2 of the peak without messing with the finished space.
Thx.. for your thoughts.
Dave