Home Re-Roof in Oklahoma - Why We Tear Off Instead of Layering Over

A home re-roof can be done two ways: nail a new layer of shingles over the old roof, or tear everything off down to the decking and rebuild. CRE Roofing does full tear-offs on Oklahoma homes, because the parts that decide whether a roof lasts - the decking, flashing, underlayment and ventilation - are the parts an overlay leaves buried. Here is how the two approaches differ and what to ask any roofer bidding your re-roof.

What "layering over" means

An overlay, sometimes called a roof-over or layover, puts new shingles directly on top of the existing ones. The old roof stays in place. It skips tear-off and disposal, which is why it sometimes shows up as the lowest bid.

Building codes commonly used across the country limit when an overlay is allowed at all. A new layer generally cannot go over a roof that already has two layers, or over one that is wet or badly deteriorated. Rules can vary by city, so the permit office has the final word.

What a tear-off re-roof involves

A full replacement is a tear-off down to the decking, not a layer of new shingles over the old ones. On a CRE Roofing job, that means:

1. Tear-off and disposal - everything comes off down to the deck, and the debris leaves with us
2. Decking repair - rotten, delaminated or hail-punctured boards get replaced, and we photograph them first
3. Drip edge and flashing - new metal at the eaves and rakes, and new flashing at every wall, valley and penetration
4. Synthetic underlayment - the secondary water barrier under the shingles
5. Ventilation - intake and ridge ventilation sized to the attic
6. Cleanup and permit - a magnet sweep of the yard and driveway, and the permit pulled in your city

Our roof replacement page goes through each step in more detail.

Why the decking matters

Decking damage is common on older Oklahoma homes, and you cannot see it from the ground or from on top of the old shingles. It shows up when the old roof comes off.

With a tear-off, we photograph the decking once it is exposed, and if boards need replacing, we show you the picture before we do the work, not on the invoice afterward. With an overlay, soft or rotted boards stay under the new shingles. New nails go into the same weak wood, and the problem waits.

Flashing, boots and vents

Flashing, pipe boots and vents are where most leaks start. Pipe boots in particular are one of the most common leak sources we find.

An overlay tends to leave old flashing in place or work around it. A tear-off replaces it. The same goes for underlayment: a new layer on top does nothing for felt that has spent decades in the Oklahoma sun. If you want to know what that layer does, read our post on roof underlayment in Oklahoma.

Heat, hail and the next storm

Oklahoma attics get hot, and attic heat ages shingles from below. Rebuilding the ventilation during a tear-off is one of the best things you can do for the life of the new roof.

Hail is the other reason. In central Oklahoma, hail ends more roofs than age does. A tear-off is also the moment to consider impact-resistant shingles or metal, rebuilt on a clean, solid deck. See our metal and impact-resistant roofing page, and ask your insurance agent whether your policy offers a discount for an impact-resistant roof.

How long a tear-off takes

Most Oklahoma City metro homes are a one to two day job once materials are on site. Steeper roofs, extra layers to remove or decking that needs replacing can add a day. Taking off two old layers instead of one is part of why some bids differ.

Questions to ask any roofer bidding your re-roof

• Is this a tear-off to the decking or an overlay?
• How many layers are coming off?
• Are the pipe boots, vents, flashing and underlayment all new?
• How do you handle decking you find bad, and will I see photos first?
• Is the permit included?

A bid that comes in well under the others is usually not better buying. It is usually a shorter list of new parts.

Common questions

Is an overlay ever acceptable?

Codes allow it in limited cases, but it hides the decking and keeps old flashing in place. We tear off so the whole roof is rebuilt as one system.

Will you replace bad decking?

Yes, and we show you photos before we do it.

How long does a re-roof take?

Usually one to two days once materials are on site.

Can my re-roof go through insurance?

If the roof was damaged by hail or wind, it may. If it is simply worn out, it is a retail job. We tell you which one you have on the free inspection. See our insurance claims page.

Start with a free inspection

If your roof is due, CRE Roofing will tell you how many layers are up there, what the decking likely looks like and whether there is a claim. Book a free inspection on our contact page.