10" High Attic, Flat Roof - Best Way To Insulate - Insulation - DIY Chatroom Home Improvement Forum

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


Thread Tools Search this Thread
Display Modes
Old 02-29-2012, 08:58 PM   #1
Join Date: Dec 2009
Location: Hagerstown, MD
Posts: 364
Rewards Points: 250

10" high attic, flat roof - best way to insulate

My bathroom is always about 10-15 degrees colder than the rest of the house. I FINALLY decided to cut a hole in the ceiling to see what I got. 2x10 rafters/joists from wall to wall, then the roof sheathing is on top (no slope in the roof, just flat on the bathroom). I was considering just stuffing in unfaced r-30 and calling it a day, but wasn't sure if I need to allow for any ventilation or not for this type of attic/roof (I'd rather fill it up entirely if I could, as I live in northern maryland).

Tonglebeak is offline   Reply With Quote
Sponsored Links
Old 02-29-2012, 10:20 PM   #2
Disabled wood vet
titanoman's Avatar
Join Date: Nov 2011
Location: California
Posts: 1,661
Rewards Points: 1,004

I would think you should put in some ventilation baffles, and vented soffits at either end of the rafter bays, if possible.
You could fir the rafters a couple inches for max insulation also, if possible.

Last edited by titanoman; 02-29-2012 at 10:23 PM.
titanoman is offline   Reply With Quote
Sponsored Links
Old 03-01-2012, 12:08 AM   #3
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,941
Rewards Points: 1,188

you absolutely need ventilation, unless you are going to get the lid spray foamed and have the whole place conditioned. for that, i'd do some reading on buildingscience.com for details, as that may be a bit trickier over a bathroom. if you don't foam it, air seal when you button the place up. how are you going to access the area? remove ceiling, or roof? if you stuff in batts, don't use fiberglass. rock wool is a better material.
jklingel is offline   Reply With Quote
Sponsored Links
Old 03-01-2012, 06:29 AM   #4
Join Date: Jun 2011
Location: Atlantic Canada
Posts: 379
Rewards Points: 252

Is this an add on bathroom (in other words, does the roof butt up against a high wall)? If so it will be difficult to ventilate properly without getting a hold of a roofer who specializes in flat roofing (if they want to slap some goop on the roof, they DO NOT specialize in flat roofing). A bit more detail would be required.

I would be hesitant to use spray foam, as it is not a question of if the roof will leak, but when, and when it does spray foam could hide the problem from you long enough to cause serious damage. Being a bathroom (aka high moisture) ventilation and a proper vapour barrier are a must.
shazapple is offline   Reply With Quote
Old 03-01-2012, 10:17 PM   #5
Registered User
Join Date: Mar 2009
Posts: 11,730
Rewards Points: 526

Read on: http://www.buildingscience.com/docum...+in+flat+attic


Find your Zone: http://publicecodes.citation.com/ico...001_par001.htm

If any ads are present below my answer or words underlined/colored, I do not condone/support/use the product or services listed/linked to, they are there without my consent.
17,000 dryer fires a year, when did you last clean the inside of the dryer near motor or the exhaust ducting?
Gary in WA is offline   Reply With Quote
Old 03-02-2012, 06:29 AM   #6
Exterior Construction
Windows on Wash's Avatar
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 26,041
Rewards Points: 878
Blog Entries: 41

Pictures will help here...
Windows on Wash is offline   Reply With Quote
Sponsored Links

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Flat Roof Repair Costs Pittsville Roofing/Siding 10 09-03-2012 11:50 PM
will a flat roof always leak............. cappuccino Roofing/Siding 6 04-19-2011 04:16 PM
Insulate attic and between roof and closets scool Building & Construction 1 11-28-2010 02:36 AM
EPDM - flat roof to sloped roof transition emtaboy Roofing/Siding 12 07-14-2010 12:12 AM
Modified bitumen vs 60 mil EPDM membrane Flat Roof doingygirl Roofing/Siding 11 01-07-2008 08:41 AM

Top of Page | View New Posts