Ventilating Attic With Two Roofs - Building & Construction - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction


Thread Tools Display Modes
Old 01-09-2011, 02:32 PM   #1
Join Date: Jan 2011
Posts: 2
Rewards Points: 10

Ventilating attic with two roofs

I purchased a 1920s-era house in 2009 that has some interesting issues I am trying to resolve on a bit of a shoe-string budget. The issue that I am soliciting input regarding is ventilation for the attic. When a significant remodel and addition was executed in 1970, a new hipped-gable roof was built over the existing nearly flat-pitched roof. Unfortunately, the builders neglected to add any intake ventilation for the resulting attic space created above the old roof. I believe there is sufficient venting into the lower attic (below the original roof), but the air doesnít flow sufficiently into the upper attic area. The existing vents are under eave type, and I believe they allow air to flow horizontally directly into the lower attic. The lower attic is too small to maneuver into, so it is difficult to verify.

After living through first summer I observed that the attic space temperature is quite high compared to the interior of the house. Additionally, Iíve noticed some moisture issues during winter months with condensation appearing on windows in the interior space below the afore-mentioned attics.

I am contemplating several options to resolve ventilation issues. I believe Iíve ordered these from least to most difficult:

1. 1. Cut holes in the lower roof at locations corresponding to the existing vents to allow air to flow from the outside to both the lower and upper attic.
2. 2. Install new soffit vents to allow air flow into upper attic. Leave existing eave vents intact to feed the lower attic
3. 4. Remove the existing eave vents (as they are ugly) and install new soffit vents to flow air into upper attic. Insulate upper attic for greater energy efficiency, relegating the lower attic part of the building envelope.
3. 3. Remove the existing eave vents (as they are ugly) and install new soffit vents to flow air into upper attic. Cut holes in lower roof to allow air flow into lower attic.

Iím pretty unfamiliar with this area of home construction and my research hasnít uncovered any similar scenarios. Iím greatly appreciative of any advice you can provide about my four options, or any that I havenít identified.



senorbungle is offline   Reply With Quote
Old 01-09-2011, 03:23 PM   #2
Chicago, IL
Michael Thomas's Avatar
Join Date: Jan 2008
Location: Chicago, IL
Posts: 1,037
Rewards Points: 500

First thing: make sure that all appliance vents, plumbing vents and chimneys are actually venting to the exterior and not into the space between the roofs - I have seen several instances where they were not (!)


Home Inspections, Infrared (Thermal Imaging) Leak Identification and Inspection Services, Roof, Attic, Building, Basement and Foundation Moisture Intrusion and Water Leak Inspections, Troubled Building Consultations - Serving Chicago and Suburbs
Michael Thomas is offline   Reply With Quote
Old 01-09-2011, 04:17 PM   #3
Join Date: Jan 2011
Posts: 2
Rewards Points: 10

Thanks for the suggestion, and certainly that's another thing I need to be concerned about. So far the only one I've found that does not vent to the outside is the range hood. To me this roof-over-roof construction seems a bit strange but I do think did a generally good job.
senorbungle is offline   Reply With Quote

air flow , attic ventilation , soffit vent

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Raccoons in the attic electricpete Pest Control 17 05-12-2011 04:02 AM
Recently Topped Up Attic with Blown Insulation...Now I have Frost/Condensation earthad1 Building & Construction 81 02-18-2011 12:42 PM
Attic fan options P550 Roofing/Siding 1 08-22-2010 12:47 PM
Attic fan options. P550 Electrical 6 08-22-2010 12:30 PM
Attic Fan AND Whole House Fan PapaGnome HVAC 6 02-15-2009 02:28 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1