QA

Quick Answer: How To Re Roof Over Existing Shingles

Can you roof over existing shingles?

You might be able to lay new shingles over existing shingles and avoid the cost of tear-off. Some roofers install a layer of waterproof shingle underlayment (WSU) over the existing shingles at the eave end, as would be done for a roof laid on bare sheathing. This provides added protection against ice dams.

Can you reroof over an existing roof?

Roofing over an existing roof is also called reroofing or an overlay. It is the process where roofers install a new roof over your existing one, i.e. add a new layer of shingles, which means that there is no tearing off of the old roof.

Is it OK to put a second layer of shingles on a roof?

Adding a second layer of shingles will make your roof hotter because heat gets trapped between the shingle layers. Increased temperatures can lead to premature aging of the shingles. Layering new shingles on top of old ones, which might be curved or damaged, can result in some visible imperfections on your roof.

Is it better to remove old shingles?

While a repair job can often be more convenient and somewhat more cost-efficient, placing new shingles over old ones is never a good idea. Whether repairing one section of roof, or a replacing a whole one, it’s always best to pull up the old shingles before putting down the new ones.

How do you add a second layer of shingles?

Make Repairs Before Reroofing Remove shingles from any area where you notice deterioration or damage to the roof decking. Replace the damaged roof deck with 3/4-inch OSB board. Add a layer of shingles over the newly repaired area before you install your second layer of shingles.

Can you put a second layer of shingles over architectural shingles?

The standard practice was that you could install a new layer of singles directly over the old layer during a re-roof. The quick answer is yes you can re-roof architectural shingles over existing architectural shingles (however you must check with the shingle manufacturer as well).

Can you put 3 layers of shingles on a roof?

No, you can’t put three layers of asphalt shingles on a roof. In most states, you’re only allowed to have two layers of asphalt shingles on a roof for fire safety reasons. However, a reputable roofing contractor will recommend a full replacement if you already have two or more layers.

Can you install metal roofing over shingles?

You’ll be able to save up to 25% in labor costs by not tearing off your old asphalt roof, installing new underlayment, or the fees to dump the old roofing materials. So, yes, you can install a metal roof over your old asphalt roof.

How long does a reroof last?

Longer lifespan – A new, properly installed shingle roof can last 20 to 30 years, meaning it could potentially outlast an overlay by a decade or more. Increased property value – A brand new roof can add more than $10,000 to your home’s resale value and also acts as a strong selling point.

How many times can you shingle over a roof?

Depending on the type of roof material used, the number of layers added to a roof range from two to three times. House roofs should never exceed three layers of shingles. Adding additional layers without excavation can save homeowners up to $1,000 in labor. Therefore, layering has advantages.

Should you tear off old roof?

In most cases, more than two layers of roofing shingles does require a tear-off. Laying new shingles over old shingles is easily prone to leaks and reduces the life of the new shingles. This alone ought to be reason enough to do a tear-off; it’s just a bad value not to.

What extra load will the roof have to hold up while shingles are being replaced?

After reviewing local building codes, the dead load for normal shingled or wooden roofs is a minimum of 20 pounds per square foot, while it’s closer to 27 pounds per square foot for a more sturdy material like a clay tile or metal roof.

Can you put 3 tab shingles over architectural shingles?

In most cases, you can apply a second layer of three-tab shingles over an existing roof that features three-tab shingles without having to tear off the existing roof. However, you cannot apply three-tab shingles over architectural shingles.

Why are multiple layers of shingles bad?

Two layers of shingles trap more heat, which in turn damages the shingles and shortens the life span of the roof. Adding a second layer could compromise the structure of your roof. Problems fixing leaks: A second layer of shingles only complicates the job when a roofer is trying to fix a leak.

Should I overlay shingles?

A: In general, it is not good practice to overlay a traditional asphalt shingle roof versus a complete tear off and replacement for the very reason you stated: you can’t examine the decking to determine if there is any damage that needs repaired.

How much does a new layer of shingles cost?

A one-story roof with a single shingle layer costs between $100 and $150 per square to remove; a double layer, $115 to $165; and triple layer, $125 to $175. If you have a particularly high roof or one that’s extremely steep, you will pay more.

Can you put metal roof over shingles without furring strips?

One option for installing a metal roof over shingles without furring strips is to use a cross-batten style. A cross-batten technique involves laying down vertical battens first. Next, the battens attach through the roof deck to your rafters. Finally, your horizontal battens are placed.

How much does it cost to put a metal roof over shingles?

You can spend anywhere from $5,000 up to $15,000 to install a metal roof over shingles when added together. This value range is for overlaying metal over existing shingles. Your costs will increase if you have to pay for a tear-off due to damaged shingles or the roofing structure.

Can a metal roof be installed over 2 layers of shingles?

In simplest terms: Yes, you can install a metal roof over shingles. Building officials in some areas will only allow a re-roof over one layer of shingles, while officials in other places may allow you to place the roof over two layers of shingles.