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11 Things to Consider When Replacing a Roof

  • Re-roofing is one of the largest home improvement investments for a home owner
  • Roofing basics should be learned before hiring a roofing contractor


After staying at our house for about six years, I started to notice more and more silverfish.

Since silverfish thrive in wet areas, I checked my attic and noticed several large water stain spots. Not enough to cause a puddle but just enough to leave stains on the roofing deck (plywood).

At that point in time, my roofing was approximately 19 years old so we decided to just replace it.

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# 1 – Roof Types (shapes)

You will want to familiarize yourself with these common roof designs and how they impact your choice of roofing materials.

Traditionally, a gable roof is the easiest to install therefore least expensive. If you have steep angled roof, multiple styles, etc. will all make the job more expensive.

Bonnet roof
Cross Gable roof
Cross Hip roof
Dutch roof
Dutch-Colonial roof
Flat roof
Gable roof
Gambrel roof
Hip roof
Mansard roof
Shed roof

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# 2 – Roofing Materials

There are five roofing materials that are most commonly used in residential setting:

  • Asphalt shingles – the most common roofing materials in residential homes due to its affordability.
    • Three tab (strip) shingles – the original and most basic asphalt shingles, made from a single layer of asphalt and have a very flat appearance; generally weigh and cost less than more expensive shingles; least $$$
    • Dimensional (architectural) shingles – considered to be a premium type, it is also referred to as laminated shingles because there are two layers of shingle pieces glued together to provide 3D look. intermediate $$$
    • Luxury shingles – luxury shingles have many of the same features found in dimensional shingles, but comes in more variety of designs with heavier materials; high $$$
    • Expected lifespan is 25 to 30 years (shorter warranty period for 3-tab shingles; longer warranty period for dimensional and luxury shingles)
3-tab strip shingles
Dimensional shingles
Luxury shingles
  • Metal roof – although there are two types of metal roofs, most homes install standing seam metal roofs:
    • Standing Seam – series of locked metal panels at the seams
    • Screw Down Panels – metal panels are fastened down using screws and washers
    • Expected lifespan is approximately 50 years
Metal roof – standing seam
Metal roof – screw down
  • Cedar shake – made from cedar and shaped into taper-sawn panels
    • Expected lifespan is around 30 years if you invest in quality materials and also live in a weather-stable area
Cedar Shake roof
  • Composite (synthetic) shingles – some are made from recycled materials and others are made out of engineered polymers designed to look like cedar shake or slate roofs
    • Expected lifespan is 40 to 50 years
  • Slate / Clay roof – premium roof system made primarily out of natural stone materials, this material is very popular in the West, Southwest and in Florida; just keep in mind that tiles are extremely heavy
    • Expected lifespan is 75 to 100 years!
Composite shingles
Slate tiles
Clay tiles

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# 3 – Roofing System Components

  • (1) Leak barrier – prevents frozen ice from creeping under shingles
  • (2) Underlayment – usually made of No. 15 felt that intercepts water; better and tougher felts are labeled Type 1 or are reinforced with fiberglass
  • (3) Starter strip -reduces the risk of shingles blowing off during a heavy storm
  • (4) Shingles
  • (5) Ridge cap ventilation – allow attic ventilation
  • (6) Ridge cap shingles
  • (7) Decking – usually made from plywood or oriented strand board (OSB). it is nailed to the rafters; in hot climates, builders may use foil-faced panels to reflect radiant heat away from the roof
  • (8) Drip edge – strips of aluminum or galvanized steel to block rain and wind from the side

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# 4 – When Should You Get a New Roof?

Here are top eight warning signs that indicate your roof may be failing.

  • Sign # 1 – Shingles are curling, cracking and blistering
  • Sign # 2 – There are several missing or loose shingles
  • Sign # 3 – The roof is sagging
  • Sign # 4 – There are dark spots on your roof
  • Sign # 5 – There are exposed roofing nails
  • Sign # 6 – There is water damage inside your home or attic
  • Sign # 7 – You see more bugs (i.e. silverfish)
  • Sign # 8 – Your roof is more than 20 years old

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# 5 – DIY or hire a contractor?

There are lots of home projects that I like to tackle but being on a second story roof to tear off and install a new roofing is not a good idea.

Perhaps if I lived on a single story ranch house, I would consider doing it.

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# 6 – Overlay or Tear Off?

Overlay is simply adding a second layer on top of the existing roofing material (where allowed by local zoning). This option is only available if you are installing a second layer of asphalt shingles on top of an asphalt roofing.

  • Pros of choosing this method is that it is cheaper as you do not need to pay for labor to remove the existing roofing materials or cart off old materials to a dump.
  • Cons of choosing the overlay method is that you are in essence papering up any existing damages which may cost a lost more money to do it in the future. In addition, if your first layer of roofing material is warped, your new layer will not lay down neatly.
Tear off
Deck replacement

On the contrary, tear off method is completely removing the existing roof shingles, underlayment protection, leak barrier, etc. down to the decking material. Sometimes even decking materials will need to be replaced if it is water-damaged.

  • Pros of choosing a tear off method is that you are starting fresh. This method allows physical inspection of the decking to address any rot / damages and can add a modern moisture barrier materials. Lastly, a new roofing shingles will lay down nicely
  • Cons of choosing the overlay method is that it is about 25% more expensive than the overlay method.

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# 7 – Getting Quotes

The best way to get a reputable contractor is a company that has done a lot of work in your neighborhood.

You should get at least three individual quotes for comparison.

Don’t always assume that the least expensive vendor is crappy and vice versa.

Also, check with BBB, Google review, Yelp, Angies and Home Advisor for any negative reviews as well as check with your state/local agencies to verify that state license is active and there are no complaints.

I ended up going with Vendor C because he got some raving reviews from some of my neighbors.

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# 8 – Beware of the Contract Fine Print

Here are some fine print stuff that you should keep in mind.


Few contractors I interviewed wanted to keep the job unofficial and skip this step. I highly recommend that you do NOT SKIP getting a permit.

Yes it will cost you around 100 bucks or so to pull the permit but this will keep the contractors honest since if they screw up, they will not be able to do future work in the same town.

This is the actual roofing permit I received once the job was completed.

In the contract, you will want to stipulate that within a week or two of giving them your deposit money, you should receive a copy of the permit application from the contractor.

You may also want to stipulate that last $500 of the balance will be paid once you receive the certificate.

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Deposit Money

Depending on the total projected cost, I think 20 to 30% deposit is a fair amount to get started to cover the materials cost.

Obviously, you do not want to pay the entire amount upfront as it leaves too much temptation for unscrupulous contractors to skip the job.

Most contractors will only accept a check or cash do not pay the entire amount upfront!

made the mistake of not negotiating the price of replacing roof deck (plywood) because it never crossed my mind.

I ended up paying upwards of $50 per sheet (when a 4×8, 1/2″ ply was going for $15 bucks).

Other things to keep in mind:

  • Decide who will pull and pay for the permit (if your town requires it)
  • 20 to 30% deposit is a fair amount to get started; do not pay the entire amount upfront!
  • Expected start and end date
  • Business liability insurance (you must get this info couple of weeks in advance of work so that you can independently verify the insurance coverage)
  • If at all possible, stipulate that subcontractors will not be used

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# 9 – Average Price

My quotes were (all priced in 2008):

  • Vendor A – $4,800
  • Vendor B – $6,800
  • Vendor C – $6,845
Welcome Letter A
Welcome Letter B
Proof of insurance
Proposal pg1
Proposal pg2

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# 10 – Things to Watch During Work

It is imperative that you observe the crew while they are working on your roof. You will want to have a paid of binoculars on hand.

Here are a few things to look for during a re-roofing job:

  • Did workers setup a way (i.e. draped tarp and a dumpster nearby) to collect waste during the removal process? Tearing off roof generates a lot of waste and it needs to be properly disposed as the work progresses
  • Make sure that exposed roofing deck is in good condition (no dark spots, depressed area, etc.)
  • Make sure ice dam shield and drip edge are installed
  • Make sure that underlayment installed is what you paid for (15 lbs or 30 lbs felt)
  • Take a look at the roofing shingle bundle wrapping to verify that it matches what was stated in the contract
  • Make sure roofers install initial course of shingles as part of the ice dam system
  • As shingles are installed, periodically check from multiple angles to ensure that they are aligned properly (i.e. straight across without wavy lines)
  • When it comes to nearby walls and chimneys, make sure that stepped metal flashings are properly installed
  • Make sure that ridge vent caps and shingle covers are installed properly
  • If possible, walk on the new roof to look for any exposed nail heads, rips, mis-matched shingles, etc. and ask the contractor to address them
  • Make sure all debris on the ground, including lots of nails, are removed

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# 11 – Signs of a Bad Roofing Job

  • Sagging rooflines?
    • Rooflines should be as straight so if you see a dip or wave, the roof may have a structural problem. Once new shingles are installed, it can get difficult to have the contractor address the issue so it is best to look closely just after old roof is removed to address any issues
sagging rooflines
  • Some asphalt shingles are in different in color
    • If you spot shingles that are different in color, it’s usually means the roofer did not have enough of your purchased shingles and possibly used a leftover stock. Again, you want to prevent this from happening so be on the lookout while shingles are hoisted on to the roof
mismatched shingles
  • One part of your roof has a different material than the rest of the roof
    • Again, this is an indication that your roofer may have ran out of your preferred materials and spinning it as giving you a higher (leftover, mis-matched) quality material for free. You do not want to make a last minute design changes like this. And reputable roofing contractors will have more materials than needed to ensure that this does not happen
  • Your roof has missing/damaged shingles
    • A new roof will never have these issues so it all comes down to either the roofing contractor improperly installing these shingles or they used a leftover (or even used) shingles
  • Reusing old flashing material
    • Flashing is the thin sheet metal piece (usually aluminum or galvanized steel) on roof edges to prevent water leaking into the home at various angles and joints along the roof. Again, quality roofing contractors will NOT use old materials
  • Roofing materials were not attached correctly
    • Most, if not all, roofing contractors use pneumatic nail guns to install asphalt shingles. Using the wrong nail type and improperly driving them in can all cause problems down the road. Unfortunately, this isn’t something that you can detect while your roof is being installed. When you do a close inspection (hopefully on the roof), squat down and look at the shingles. Are they all laying down flat? Do you see any bumps which could mean some nails were not hammered in properly? The best way to prevent this from happening is to hire a reputable roofing contractor.
  • Stains on the roofing
    • Quality roofing contractors will proactively identify and recommend replacing rotted or damaged roofing deck. Please, please do not try to save few bucks by leaving these damaged plywood in-place as your new roofing shingles will not last as long. Installing new shingles on top of a damaged decking may even void your warranty. Yes, it will cost more money to replace the damaged decking but it is far better to address the problem now than later
  • Uniformity
    • An incorrectly installed roof will not wear a uniform fashion. Instead, you will most likely see different colored shingles, damaged drip edges or worn-out vents that have been reused. Frequent visual inspections will help you notice issues. Document these problems and contact your roofing contractor. Most reputable contractors have 20+ year labor warranty to address and installation problems.

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It is in your best interest to conduct research and due diligence to avoid a bad roofing contractor. You do not want to go down the road of hiring a bad contractor thinking that they will fix any issues down the road. Once these bad contractors get all their money, all the hoopla about labor and installation warranty are as good as the paper it is written.

You also want to closely observe their work while your roofing is being replaced.

Be diligent and don’t be shy about asking questions!

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