Why Does My Roof Look Wavy? (We Have The Answer)

Patricia Oelze
by Patricia Oelze

Having a wavy roof may sound like fun but it really isn’t. In fact, it can be a sign of something majorly wrong up there. Wavy roofs are not normal, and they do not happen on their own naturally. So, what are some of the reasons your roof can look wavy.

If you are wondering why your roof looks wavy, the culprit is likely distorted shingles due to a warped foundation, damaged underlayment, or overheating. If your roof shingles have just been placed, they may also look wavy because they have not yet bonded. If none of these apply, it may be an error in the shingles’ production.

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Will A Warped Foundation Make My Roof Look Wavy?

Everything has a foundation, not just your house. The roof has its own foundation. It is made up of the framing and the decking. Your foundation is made up of the plywood that covers the whole roof. The shingles are attached to the plywood and if it is not straight, it can cause a visible wave in your roof.

This can be a very dangerous situation. This can indicate that water is leaking through the shingles or it can also cause a problem with ventilation. If you think that you may have a warped foundation, you need to contact a professional as soon as possible.

Fixing A Roof Foundation Problem

The foundation of your roof, or deck, is the most important part of your roof just like the foundation is the most important part of the house. It can be made of several different materials such as:

  • Cementitious wood fiber
  • Gypsum
  • Lightweight insulating concrete
  • Wood sheathing
  • Cold-rolled light-gauge steel
  • Thermoset of compacted asphalt fill

To take care of the problem, you will have to start over from scratch. This is a costly and lengthy process but is completely necessary since your roof is compromised. Leaking, ventilation problems, and possible structural damage are all possible if this is not fixed properly.

Damaged Underlayment Makes Your Roof Wavy

The underlayment is whatever is between the roof deck and the shingles. If you have asphalt shingles, your underlayment is typically felt paper. If your felt paper is wet or not placed correctly, it can cause waves in your roof.

If it is just that the felt needs to settle or dry because it is new, the problem will fix itself. But if it is caused by water getting under the shingles or if a raccoon or some other pest has attacked your roof to get inside, you will need to repair it.

Fixing the Felt

If the underlayment (felt paper) is damaged, you can fix this by replacing the felt paper in the areas that are wavy. The roofers will have to come back and fix this for free as long as you catch it right away.

Bubbled felt paper may also just flatten out on its own. But if it has not gotten better in about a month, you need to call the roofers back to fix the job.

Heat Distortion

Severely high temperatures can really damage the roof materials, causing waves and other weird distortions. The asphalt in the shingles can melt, bubble, or crack. In addition, the underlayment can become damaged if it is subjected to high heat and sunlight during installation.

Heat can cause problems with other parts of the roof too. Even though shingles are made to withstand heat, extreme heat can still cause shingles to crack or warp. The caulk can also melt or deteriorate from the heat, which lets water under the shingles where it causes warping.

To prevent these from happening, you can try several things. Some of these include:

  • Install a reflective seal or coating
  • Provide proper roof ventilation
  • Paint the roof white to reflect the heat
  • Inspect the roof regularly

Bad Workmanship

Did your roofers lay the asphalt over old roofing materials? In most circumstances, this is just fine and will not cause a problem. However, if the shingles underneath are unnaturally wavy already, it may be the reason your roof has waves. There are other issues that inexpert installation can cause such as:

  • Bubbled felt paper
  • Misaligned shingles
  • Bad measurement
  • Wrong sized shingles
  • Low-quality materials

Each of these has its own problems but they can all be the cause of waviness. Fortunately for you, these are also fixable without having to get a whole new roof. In fact, some of these are quite simple to fix.

Misaligned Shingles

Misalignment of the shingles is a problem that usually only happens if you do not use professional roofers. Even though roofing is not a complex job, it is an exact process. The roofers have to measure everything precisely and carefully.

The cuts must be made properly as well. Unfortunately, the roof will need to be redone in the spots that are not lined up correctly. The problem is, do you trust the inferior roofers to do the job right the second time? It may be better to get your money back and hire someone else to fix it.

Too Many Shingles Are Not Better

Even though it is usually fine to install new shingles over the old ones, if the old ones are not level or if there is already another layer of shingles under there, it can cause the waviness you see. Unfortunately, your roofing company is going to have to take it all off and start over.

Bad Shingles Can Be Fixed, But by Who?

Your roof could also be wavy if the shingles or other materials the roofers are using are not up to code. Or they may be up to code but are just inferior. That is another reason why you should check out your roofing company before using them. Have them redo it and make sure they use the best products this time.

What Is The Underlayment For And Does My Roof Need It?

The underlayment is important to keep the elements from getting to the other parts of the roof. Just having a layer of shingles is not enough to protect your home from rain and snow.

All roofs must have an underlayment to protect their home from high wind and ice damming. It can also help prevent damage that can be caused during roof installation or repair. For example, it will keep all the debris and water out of your house while the roofers are working.

The underlayment is one of the layers of protection that you need to protect your house from water damage. There are several types of materials for roof underlayment. These include:

  • Felt made from paper soaked in asphalt is not used as often anymore since new synthetic and rubberized options came along.
  • Synthetic polypropylene sheeting has a superior heat resistance and is lighter and thinner than other types of underlayment. It is easier to install and lasts longer as well.
  • Rubberized self-adhering underlayment is the best for those who live in areas with high temperatures such as Arizona, Florida, or Louisiana. However, it also costs more than other types of underlayment.

Related Questions

How Can I Tell if My Underlayment Needs to Be Replaced?

Depending on what type of underlayment you have on your roof, it should last about 15 to 20 years. But it can need to be replaced anytime if the product is inferior or was not installed properly.Besides waviness in the roof, the other main symptom of bad underlayment is a leaky roof. Some of the signs of a leaky roof include:

  • Spots on your ceiling
  • Missing shingles
  • Damp walls
  • Dirty or clogged soffits
  • Rusty gutters
  • Stains or mold around your bathroom fan
  • Mold on the ceiling

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What if My Roofing Company Will Not Fix the Damage?

First, you have to know what the problem is, exactly. Have a different roofer take a look at it. Make sure it is someone who is reputable and trustworthy. Whatever the roofer claims is wrong with it, get it in writing to show the original company.

You can also take photos of the problems. For example, if your roof is leaking into your home or you have wet spots or mold on the ceiling.

Check your warranty. Make sure you are covered for whatever the problem is and that you can prove it is the fault of the roofing company. Then, if they will not do what they should, call a lawyer.

Patricia Oelze
Patricia Oelze

I am a DIYer who loves writing about anything home-related. When I am not writing, you can find me studying for my PhD in Psychology, photographing nature, and swimming at the lake with my grandkids.

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