Rafter Size

Reply

  #1  
Old 12-01-01, 09:09 AM
Visiting Guest
Posts: n/a
Rafter Size

hi all, hoping to get advice in which direction to head first. Live in a 15 yr old cape style house we purchased 4 yrs ago. Original asphalt shingle 12/12 roof, 2x6 RAFTERS 24"o.c., . Upstairs is gabled wall with storage spaces included in heated area/envelope, venting is gable to continuous soffit vents. We are located in the mtns of northern Vermont - severe snowfall, precipiation, temp. etc. Roof is shot and have ordered a metal standing seam for spring (they cant install any sooner and I can fend off any water damage by continuing to rake off snow). House needs lots of work (rotted siding, uninsulated basement (poured conc. walls and floor) very damp/humid conditions inside with air infiltration from living area to decking. Although individual shingle condition is intact , from the condensing moisture in winter, decking ruptured and destroyed roofing integrity - also severe ice damming, leaks, etc. So my task list is long. I want to fix this house correctly and throw my money into the right battle. A metal roof assuredly is an asset in this region but not if the roofing structure is going to continue to rot underneath it. To me it seems that the rafters should have been 2x12 or another framing method so an unusual amount of space could have been made to dedicate itself to insulation from this cold weather region. So with all that background my question is this: Does anyone think that this problem will be resolved if I correct all the other details : marginal attic venting, high humidity/ rot , air leakage, closing out behind the kneewall? Or will I always have problems with 2x6 rafters and need to replace them for additional insulating space? 2x12 reafters? There is very little room between the top sill of the first floor wall and the decking for these kind of regional sub-zero temps. With the baffles in the 2x6 rafters, there is only about 4inches left at best between the sheet rock. Is this standard rafter framing design for cold climates or did the builder cheap out in lumber? Awfully sorry about the length of this post. Any help would be greatly appreciated. Thanks. -dave
 
Sponsored Links
  #2  
Old 12-01-01, 10:14 AM
Member
Join Date: Nov 2001
Location: USA
Posts: 1,873
Vermont Energy Investment Corp. (VEIC) ask for Ken Tonihaka, Senior Energy Analysis, Building Performance Specialist. If you want someone to look at it, he's your guy. I believe you can access that company through the Vermont's Utility website.

If you're going to change the rafters to 2x12's, you might as well tear off the second floor and make it a colonial. About the damp basement, ask Ken about neutral pressure zones in structures and its impact on damp basements.

Ice damming, Ken was involved in at least two case studies I know of, that is widely accepted by building performance specialists and Utilities nation wide. Both studies were in Vermont.

As far as air infiltration, Ken teaches proper application for blower door throughout the U.S., I can't think of anyone that has more knowledge on air infiltration.
 
Reply

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


Thread Tools
Search this Thread
Display Modes