Insullating Large Cathedral Attic In Old Victorian Home - Insulation - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Insulation

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 08-30-2012, 09:26 AM   #1
Newbie
 
Join Date: Aug 2012
Posts: 19
Rewards Points: 10
Default

Insullating Large Cathedral Attic in Old Victorian Home


We're still unsure about how to finish off the attic in our large old home. It has 1800 sq. feet of gables/ceiling and 700 sq. feet of gable walls.

Most insullators that have seen the space want to spray CCF but I have apprehensions about this process. First, the roof is 8 years old and was cheaper shingles layed flat on the tarpaper with no plywood down first, so the CCF would come in direct contact with the roofing (we're in zone 4/5). The rafters are old lumber with only 3 1/2 max. space to fill with the foam (not enough R value probably?). It's a very tall victorian and if there was a roof leak we wouldn't know about it and it's prohibitively expensive to find a roofer to get up there to deal with the roof. Plus it sounds like when you use CCF that you then need to condition the space 24/7, which means we can't close the space off when not in use, but still have to pay for some form of AC/Heating to keep the temp/humidity in good range. (One specialist said we don't need any air venting that you seal the space, the end, and another said we had to have an air venting system and his cost for that was an extra $1,000).

Currently we have 2 gable vents and 4 roof vents and soffit vents around, but the roof vents are only on two surfaces of the roof and there are more like 6 or 8 surfaces because of gables on every side. No ridge vents.

What I'm thinking would be a safer method than CCF would be to fir out my rafters another 2", leave some air space and cut insullation board to fit inbetween the rafters, install ridge vents and finish with one more layer of board and then drywall, probably having to sacrifice the peaks and do a slightly dropped ceiling - so the soffits would supply air up to the ridge vents, toe walls all around insulated on the backside as well.

Is there anything wrong with using the board and doing it this way?
Insights welcome!
Thanks

Advertisement

Heidi Kellner is offline   Reply With Quote
Old 08-30-2012, 10:05 AM   #2
Member
 
GBrackins's Avatar
 
Join Date: Apr 2012
Location: Fairhaven, Massachusetts
Posts: 2,877
Rewards Points: 2,032
Default

Insullating Large Cathedral Attic in Old Victorian Home


a few photos would be nice

and if I understand your post correctly you are saying they laid tar paper over the rafters without any roof sheathing???????????

Advertisement

__________________
Gary

"You get what you pay for, and sometimes free costs more!"
GBrackins is offline   Reply With Quote
Old 08-30-2012, 10:10 AM   #3
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,774
Rewards Points: 664
Default

Insullating Large Cathedral Attic in Old Victorian Home


No matter what type roofing you have there's no way to install it without something to attach it to.
There's no form or roofing I've ever heard of that's just layed over tar paper without some form of sheathing.
joecaption is offline   Reply With Quote
Old 08-30-2012, 10:15 AM   #4
Newbie
 
Join Date: Aug 2012
Posts: 19
Rewards Points: 10
Default

Insullating Large Cathedral Attic in Old Victorian Home


there is no solid decking. you can see the black underlayment. the only decking is the old boards laid across the rafters which are many inches appart, so lots of roofing nails poke through the roof all over the place - make sense?
Heidi Kellner is offline   Reply With Quote
Old 08-30-2012, 10:16 AM   #5
Newbie
 
Join Date: Aug 2012
Posts: 19
Rewards Points: 10
Default

Insullating Large Cathedral Attic in Old Victorian Home


there is spaced sheathing - no solid plywood deck - very odd to me and mentioned as odd by one other roofer who has been in the attic and not mentioned as odd by another
Heidi Kellner is offline   Reply With Quote
Old 08-30-2012, 11:47 AM   #6
Member
 
GBrackins's Avatar
 
Join Date: Apr 2012
Location: Fairhaven, Massachusetts
Posts: 2,877
Rewards Points: 2,032
Default

Insullating Large Cathedral Attic in Old Victorian Home


yes, that makes sense, especially if you have an older home.

plywood was not developed until the 40's, I believe after WWII so board sheathing was common. My old place was built in the 1850's and had board sheathing about 24" in width and had gaps between the boards so it could expand when it got wet. tar paper and weather resistant barriers were not required way back when, of course in most places there were no building codes either
__________________
Gary

"You get what you pay for, and sometimes free costs more!"
GBrackins is offline   Reply With Quote
Old 08-31-2012, 11:04 AM   #7
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 7,128
Rewards Points: 3,292
Default

Insullating Large Cathedral Attic in Old Victorian Home


Your idea of rigid foam with a vent space between the deck and the foam is a solid one.

You can either continue to add rigid foam to that space and cover the rafters with it until you get the proper R-Value for that region or spray with with foam as well.

Advertisement

Windows on Wash is online now   Reply With Quote
Reply


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
Ranch Style Home Attic Ventilation ulrichfolkers Roofing/Siding 28 06-29-2012 11:10 AM
New home construction.. Small attic minimal insulation Robert95z Insulation 9 06-12-2012 01:27 AM
attic stairs for attic hvac installation scrolup HVAC 1 04-15-2012 01:53 PM
Attic home theater construction Cinema Builder Project Showcase 23 11-19-2009 11:29 PM
Victorian Home in sleepy Indiana town warrenj Interior Decorating 1 01-08-2008 09:57 AM




Top of Page | View New Posts