Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Roofing/Siding


Thread Tools Search this Thread Display Modes
Old 08-30-2010, 11:28 AM   #1
Join Date: Aug 2010
Posts: 1
Rewards Points: 10

removal / insulation

if you have one layer of shingle roofing, do you have to remove the old roof before putting on a new one? can you leave the old roof as an insulating layer? or, what are other materials to use if you want a layer of insulation of some kind under the new shingles?

mlysell is offline   Reply With Quote
Old 08-30-2010, 12:04 PM   #2
Join Date: Aug 2010
Location: metro
Posts: 1,310
Rewards Points: 852

removal / insulation

shingles are not insulation. you can put down a 1/2in board insulation over the decking first

federer is offline   Reply With Quote
Old 08-30-2010, 12:19 PM   #3
Join Date: Jul 2010
Location: Ontario Canada, Toronto to be exact.
Posts: 1,373
Rewards Points: 500

removal / insulation

That is actually a great and very straight-forward question, with an equally great and straight-forward answer. You can generally lay a new roof over the old without any problems as long as:

1) You only have one layer of asphalt shingles on the roof. Most roof frames can support two layers of asphalt shingles, rarely three this all depends on the framing, of course.

2) The shingles lay fairly flat. The new shingles will take on the shape of the old, so if the old shingles are very curled, twisted, or buckled, the new roof will eventually look the same AND the life span of the new shingles may be decreased. This may also void the manufacturer's shingle warranty.

3) There are no existing leaks from undetermined sources. Just putting a new roof over an old roof will not necessarily fix underlying problems, such as with flashing or roof vents. These leaks will most likely recur unless they are properly repaired prior to installation of the new roof.

4) You were satisfied with the performance of the old roof... e.g. no occasional leaks during rainstorms, etc. This refers back to item (3)... new roof over old roof may not guarantee elimination of leaks.

5) An examination of the roof deck or underlayment shows it to be solid. If there is any widespread warping or softness, repair will necessitate the stripping of old shingles. If the area is large enough, it makes sense to restore the entire roof to new condition.

Ideally, your or your contractor should repair, reseat, or (ideally) replace all flashing around chimneys, valleys, vents, etc. He should also cut off or replace any curling shingles so the new ones lay flat. If you have had ice dam leakage, he should also remove the bottom few feet of old shingles and install an ice and water shield right against the roof sheathing plywood.
You can then be assured that your roof will have a long and healthy life!
epson is offline   Reply With Quote
Old 08-30-2010, 04:49 PM   #4
Doing This Way Too Long
Join Date: Jun 2008
Location: North Idaho
Posts: 1,160
Rewards Points: 524

removal / insulation

Well put epson. It's always ideal to tear off the existing to be able to inspect the soundness underneath as well as having a clean slate to start with. There is nothing wrong with going over existing as long as it is still relatively smooth and flat. Federer, sorry, recovery board has no business on a shingle roof, it is used for low-slope roof applications.
OldNBroken is online now   Reply With Quote
Old 08-30-2010, 05:29 PM   #5
Join Date: Jul 2010
Location: Ontario Canada, Toronto to be exact.
Posts: 1,373
Rewards Points: 500

removal / insulation

Thank you OldNBroken...
epson is offline   Reply With Quote
Old 08-30-2010, 08:04 PM   #6
Registered User
Join Date: Mar 2009
Posts: 9,967
Rewards Points: 2,000

removal / insulation

Check locally, you may have something as this:
16. Section R907.3, #4 does not allow an overlay of asphalt shingles on re-roofing since
Broomfield is considered a “moderate” hail damage area per Figure R903.5.
Therefore all re-roof permits will require a complete removal of old roofing.
From: http://www.ci.broomfield.co.us/build...andout0308.pdf


If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote

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
Cape Cod Style House Attic/Crawl Space Insulation Help Danielg Insulation 24 05-21-2012 09:20 AM
removal of exterior sheathing to apply spray-foam insulation from the outside raymaccallum Building & Construction 4 03-24-2011 06:52 PM
How To Install Rigid Foam Insulation on Concrete earthad1 Building & Construction 9 10-26-2010 10:49 AM
Do it yourself insulation removal spowell612@knology.net Building & Construction 2 12-30-2008 07:43 AM
Installing new insulation in my basement and removing the old moldy insulation. Fixitgeorge Remodeling 3 10-17-2006 09:33 PM

Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.