Prevent your leaking chimney from causing costly damage to your property. Knowing how to detect and repair a leaking chimney will help you keep your structure dry and safe.

atlantacommercialroofingcontractors.com gathered information on how to identify leaks in your chimney, what causes them, and how to repair them.

Chimney Leaks

Every functioning chimney has one feature in common, a hole in your property. When the engineering of your chimney fails, it can allow water in, sometimes unnoticed. Here’s how to identify a chimney leak:

• Pooling water near and/or around your fireplace or stove
• Wet spots or streaks running down the wall near your chimney
• Wet spots on the ceiling around your chimney
• Wet framework around your chimney in your attic
• Water or condensation in the firebox
• Sound of dripping or trickling water in the chimney
• Cracked or spalled masonry (internal or external)
• Musty or moldy odors after a rainstorm

Note: While leaks can pop up at any time, most will develop and become evident in the spring and summer after severe, rainy weather events.

Watch this video to see what brick and mortar problems look like on a chimney.

Chimney Leak Causes

Once you suspect that you have a leaking chimney, such leaks can be traced back to one of the following six installation or material defects:

1. Missing or Poorly Installed Chimney Cap – If your chimney is not covered by a chimney cap, it is poorly installed, or it is too small, rain can enter your flue and fall down the chimney, soaking masonry and brick.

2. Damaged Chimney Crown – The chimney crown is a cement cover atop your chimney that protects flue tiles and chimney liner. When the chimney crown is damaged or cracked, water can cause moisture damage throughout the flue system, fireplace, and damper.

3. Cracked or Missing Chimney Liner – A chimney liner directs combustion byproducts away from your property while protecting the inside of the flue and the chimney’s masonry material from getting soaked by condensation when chimney temperatures cool down.

4. Faulty or Poorly Installed Flashing – Flashing is the material used to seal a chimney’s penetration through a roof. This flashing is supposed to divert rainwater from coming through the roof, eventually damaging your chimney and property.

5. Brick and Mortar Damage – The exterior portion of your chimney is exposed to all weather conditions, all of the time. Brick and mortar damage can occur from weathering, poor construction, and/or impacts from uncontrolled vehicles or falling trees.

6. Missing or Damaged Chimney Cricket – Another common cause for chimney leaks is ponding water on the penetration’s uphill side. This ponding water can deteriorate flashing, damage brick and mortar, and result in significant roofing system damage. A properly installed chimney cricket creates a sloped high point to divert water that would otherwise pond against the chimney.

Now that you have located the source of your chimney leak, repairs should begin immediately to prevent further damage to your chimney or property.

Repairing Chimney Leaks

Some chimney leaks can be repaired by the property owner, while other repairs may require professional assistance. Consider the following:

1. Installing or Replacing a Chimney Cap – If you can safely get on your roof (only perform this work with proper fall protection), the following steps will help you properly install a chimney cap:

• Measure the flue at the chimney top
• Purchase an appropriately sized chimney cap (the bonnet or roof of the cap should be twice as large as the flue opening)
• Read the instructions and gather the tools you will need
• Install the chimney cap according to the manufacturer’s instructions
• Make sure all fasteners are tightly secured, and the cap is securely in place

Tip: Stainless steel caps are generally higher quality and more durable.

2. Repairing or Replacing a Chimney Crown – This repair can be done as a temporary or permanent fix. Consider the following:

• (Temporary) Seal a cracked chimney crown with silicone caulking, an elastomeric coating, or other sealants as a temporary fix.
• (Permanent) Remove the damaged crown, build a wooden form (to hold the cement in place until fully cured), add rebar (to strengthen the crown), and pour a good quality cement mixture into the form and over the rebar.

Note: The temporary fix above will likely last two or three years before failing.

3. Installing a Chimney Liner – Installing or replacing a chimney liner is an easy project for property owners that enjoy DIY projects. (The following configuration will connect to a stove pipe. There are multiple configurations for different chimneys and/or appliances.) The following steps will help you install a new chimney liner:

Step 1 – Gather the tools you will need:

• Cutting or razor knife
• Flathead screwdriver
• Caulk gun
• Protective work gloves
• Safety glasses
• Hacksaw or Electric grinder
• Power drill

Make sure your tools and equipment are in good working condition.

Step 2 – Assemble the chimney liner kit:

• Stainless steel chimney liner
• Connector (some installations may require a two-part tee connection)
• Top plate
• Rain cap

Note: Chimney liner kits can be customized to fit any chimney and/or appliance/fireplace.

Step 3 – Remove the plastic wrap the liner is coiled in. Straighten the liner, making sure to avoid puncturing it. Straighten the liner out as well as you can.

Step 4 – Connect the tee to one end of the chimney liner. Use a tee with a looping hose clamp to avoid drilling screws through the liner.

Step 5 – Insert the liner and tee (tee first) down the chimney flue. Lower the liner until you reach the thimble (the thimble is the hole on the side of the chimney where a stovepipe is attached).

Step 6 – Complete the tee connection installation:

• Insert the horizontal part of the tee (hose clamp end first) into the thimble.
• Work the vertical part of the tee through the horizontal hose clamp until the edges of the tee are inside the horizontal section. 
• There is a worm screw inside the horizontal part of the tee. Tighten the worm screw until the two parts of the tee contact each other.

Step 7 – Connect the stovepipe. Stovepipes typically come with three screws per connection joint. Drive the screws into the horizontal part of the tee and through the stove’s exhaust collar.

Step 8 – Install the top plate:

• Run a bead of silicone sealant along the top edge of the flue
• Run the chimney liner through the top plate and place the top plate squarely atop the flue
• Center the top plate on the flue and secure the top plate by screwing in the locking bolts to the sides of the flue.
• Cut the excess liner, so it is flush with the top edge of the top plate.
• Once the liner is cut flush with the top plate, tighten the worm screw, so the hose clamp tightens around the liner.
• Install the cap over the top plate, and tighten the clamp to secure it in place.

Note: When chimney liners are purchased as a kit, all of the pieces requiring assembly should be fitted, only requiring simple fasteners.

4. Repairing Damaged or Installing New Flashing – Over time, flashing can be damaged by severe weather, material decay, or time. Similar to replacing caulking around door or window joints, scrape away the old caulking and reapply with a sealant. You can also find two-part kits containing a reinforcement fabric and elastomeric sealant. Utilizing a fabric with the sealant will increase its life. This repair, however, will only provide a few years of chimney leak relief.

If your chimney flashing is deteriorating, it is likely that your roofing system may be in decline. Read more about flashing and you will understand its purpose and the various types.

5. Repairing Brick and Mortar Damage – This type of repair requires the replacement of the damaged brick and mortar. Short-term solutions like caulking will only last for a matter of months.

If you are not comfortable with masonry, hire a trusted handyman or contractor to remove and replace damaged or cracked bricks and softening mortar.

6. Replacing or Installing a Chimney Cricket – Replacing and/or installing a chimney cricket is considered a major chimney repair. This repair should only be performed by a trusted chimney service or a professional roofing company.

Watch this video to see a well-installed chimney cricket.

Note: If you have any doubts or difficulties regarding any of the chimney leak causes and/or repairs mentioned in this article, contact a professional chimney service or roofing company to perform the needed repairs.

If after reading the article you have ruled out the chimney and think something else may be causing the leak, read this article to learn 3 other roof leak causes and solutions.

Chimney Leaks and Repairs

In this article, you discovered how to identify chimney leaks, their causes, and how they can be repaired.

By taking swift action to halt and repair chimney leaks, you are protecting your property from extensive water damages and costly repairs.

Ignoring the need to repair your chimney can result in catastrophic damages requiring thousands of dollars in professional repairs.

Sources:
csia.org/fireplace_anatomy.html
putnam.cce.cornell.edu/energy/heating-with-wood/wood-stove-safety
uidaho.edu/-/media/UIdaho-Responsive/Files/Extension/topic/forestry/WFS5-Chimneys.pdf
ideals.illinois.edu/bitstream/handle/2142/54670/1206810_F7_0_1945_chimneys_and_fireplaces_opt.pdf?sequence=2&isAllowed=y

See Chimney Leak Repair for the first version of this content.

Without knowing the pros and cons of TPO and PVC, you risk buying a roofing system that’s not suitable for your specific property needs. Even though the membranes may appear to be the same, PVC and TPO roofing systems are quite different.

atlantacommercialroofingcontractors.com gathered essential information about the composition and differences between PVC and TPO roofing systems.

PVC vs. TPO – What Is Their Composition?

Looking at a completed PVC or TPO installation, you may think the material looks identical. Still, the two are very different in composition.

PVC (Polyvinyl Chloride) – This membrane consists of two PVC plies that sandwich a polyester reinforcement sheet. Included in the manufacturing of PVC plies are:

• Ultra-violet light inhibitors
• Color pigments
• Fiberglass or polyester reinforcement
• Plasticizers (for plasticity and flexibility)
• Biocides (help deter mold, bacteria, algae, rodents, and insects)

Hot-air welded seams help PVC roofing remain watertight under a variety of severe weather conditions.

TPO (Thermoplastic Polyolefin) – To produce the TPO membrane, manufacturers will polymerize polypropylene and ethylene-propylene rubber. Like PVC, two TPO plies sandwich a polyester reinforcement sheet. The following are used in the production of TPO plies:

• Ultra-violet light inhibitors
• Color pigments
• Fiberglass
• Talc

Due to the composition of the membrane, plasticizers are not required for its plasticity or flexibility. When designed using the right processes, they perform very well, even in harsh conditions.

Like PVC, TPO employs hot-air welded seams to stay watertight during severe weather and pooling of water. To learn more about TPO roofing system, visit atlantacommercialroofingcontractors.com/tpo-roofing-system-explained/

PVC vs. TPO – Performance Comparison

The following chart will help you compare the performance of TPO and PVC roofing materials and determine the best selection for your new commercial roofing system installation:

In addition to the information above, the following should be taken into consideration:

TPO presents superior results for tear and break strengths, while PVC outperforms in chemical resistance, fire resistance, and overall cost. Restaurants or buildings with grease traps on the roof would be better served by a PVC roofing system.

When it comes to durability, the thickness of TPO and PVC membranes influence their lifespan and pricing significantly. It is strongly recommended that the thickest membrane available (within your budget constraints) be utilized.

Tip: Do not base your roofing system selection on price alone. If you choose to install TPO products, have your contractor provide information about the manufacturer. Work with contractors whose manufacturers have 20 years or more in TPO production and offer a clear warranty policy on their products.

PVC vs. TPO – Warranties

For the purchase of a PVC or TPO roofing system installation, there will be two warranties to take into consideration before closing any deal. First is the manufacturer’s warranty. This warranty will typically cover any defects in the manufacturing of the roofing membrane.

The second warranty is provided by the roofing contractor to cover his workmanship. This warranty should include what items are covered and what actions will void the warranty.

Since the coverage and duration of these warranties depend on the contractor and the roofing system manufacturer, this is on a case-by-case scenario and there is no clear advantage for TPO or PVC.

Tip: Only agree to the installation of a TPO or PVC roofing system once you are satisfied with the coverages promised by the manufacturer’s and contractor’s warranties. Upon completion of the installation, ensure that your warranty certificates and descriptions are kept with your roofing documentation.

PVC and TPO Roof Differences

In this article, you discovered the differences in composition, performance, and durability of TPO and PVC roofing systems.

By knowing how TPO membranes differ from PVC membranes, you can make informed decisions regarding the appropriate roofing system for your commercial building.

Without considering your building’s needs and which roofing system best meets them, you risk making a capital investment on a roof that will likely fail prematurely.

Sources:
astm.org/SNEWS/AUGUST_2003/obeoli_aug03.html
everybodyneedsaroof.com/thermoplastic-membranes
firestonebpco.com/us-en/roofing/tpo-roofing-systems
vinylroofs.org/
rci-online.org/wp-content/uploads/2003-09-whelan.pdf

See The Difference Between PVC and TPO Roofing Systems for the first version of this content.

Prevent your flat roof system from collapsing under the weight of standing rainwater. Without sufficient drainage, water can build up on your commercial roof and cause catastrophic losses when the roof succumbs.

atlantacommercialroofingcontractors.com gathered information on three roof water drainage systems and how they remove potentially thousands of pounds of water from your commercial flat roofing system.

Roof Drain Types

Whether you are installing a new roof or performing renovations on an old roof, the drainage system must be considered and able to usher water off of the roof with ease. The following are three principal flat roof drainage systems:

Inner Drains – These drains are commonly found on large building roofs near the center of the building. Inner drains provide the following benefits:

• Attached to a system of pipes that drain water through the roof, water is kept from the foundation and walls.
• Since the building and walls naturally protect inner drains, there is no concern for their freezing, cracking, or failing during the winter months.
• Inner drain strainers help keep debris from clogging the drain pipes and can be custom-made to fit your roof and regional climate.

Some essential issues to take into consideration are:

• A small amount of debris can render the strainers ineffective, clog the system, and cause water to pool on your roof.
• Verify the appropriate number of drains for the size of your roof. Too few drains and the system could easily be overloaded, causing water to back up and pool on your roof.
• Inner drains are more expensive to maintain. These drains require a specialized technician to service, clean, and maintain them.
• Of the three drain systems presented here, inner drains are the most expensive to install.

Rain Gutters – With the ability to serve all types of roofing systems, rain gutters together with downspouts are the most common type of water drainage system in use. Gutters offer the following benefits:

• The system is inexpensive
• Easy to install
• Effectively controls the flow of watershed from a roofing system
• Shields doorways, vents, and windows
• Keeps water from pooling near the building

Some essential issues to take into consideration are:

• Gutters require maintenance and cleaning year-round
• Gutters are prone to becoming brittle and cracking
• Gutter brackets may come loose or give way under excessive water or leaf weight
• In winter, ice dams can cause cracking
• Downspouts may clog causing water to back up and overflow in the gutter

Scuppers – This drainage system consists of along the outer walls (curbs) along the roofline. Water passes through a metal box that surrounds and protects the scupper. Consider the following benefits:

• Installation of the drainage system is extremely low cost
• If designed wide enough, there is virtually no clogging
• Water is propelled away from the building
• Custom scuppers can add to the building’s architectural appeal
• This draining system is almost maintenance-free

When the design and installation of scuppers are carried out correctly, the system provides the best value of the different drainage systems. Thus, scuppers are preferred for the efficient draining of water from your flat roof system.

The only issue with scuppers is when they are attached to downspouts or gutters, which may clog – scuppers function best when unattached from other systems.

Roof Load and Water Weight

Water removal from your roofing system is of supreme importance. As water pools and rises, it adds weight to your roof’s load and can cause a catastrophic roofing system failure.

A gallon of water weighs 8.34 pounds. During a rainstorm that drops a half-inch of rain, 300 gallons of water can accumulate on a 1,000 square foot roof. That is an additional 2,502 pounds added to your roof’s load.

To calculate rainfall accumulation or runoff, use the following equation:

1) Convert the footprint of your roof to inches. A 50’ by 50’ roof would be 600” by 600.”

2) Multiply the square footage of the roof (600” X 600” = 360,000”) by the number of inches of rainfall .5” for this example which equals 180,000

3) Divide the number by 231 to get the number of gallons (231 cubic inches = 1 gallon). In this case, 180,000 divided by 231 equals 779.22

4) 780 gallons of water weighs about 6,500 pounds, potentially added to your roof.

In this example, we see the potential for a roofing system partial or total failure due to an exceeded load capacity. To learn more about commercial roof loads, read atlantacommercialroofingcontractors.com/what-is-commercial-roof-load-why-you-need-to-know/

Commercial Roof Drainage Systems

In this article, you discovered information about three types of water drainage systems for commercial roofs and the impact that pooling water can have on your roof load.

By installing a drainage system that facilitates water runoff from your roof, you are extending the life of your roof and making the building a safer place to be.

If you fail to provide adequate drainage or regular maintenance to keep your systems working properly, the structural integrity of the roof, building, and its occupants are at risk.

Sources:
http://www.ashireporter.org/HomeInspection/Articles/Flat-Roof-Drainage/2554
citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.359.7775&rep=rep1&type=pdf
digitalcommons.calpoly.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1069&context=aen_fac
sciencenotes.org/much-gallon-water-weigh-easy-calculation/

See 3 Commercial Roof Water Drainage Systems for the first version of this content.

Is TPO the best flat roof system for your property? This question is frequently asked by property owners that need a new roof, and we have the answer.

As a relative newcomer to the roofing materials industry, TPO roofing systems have gained extraordinary popularity and are being used throughout the United States. Due to its durability and cost efficiency, TPO should be considered when re-roofing or installing a new roofing system.

atlantacommercialroofingcontractors.com takes an in-depth look at the definition, installation, warranty, cost, and problems associated with TPO roofing systems while answering some of the most frequently asked questions about it.

TPO Roofing Explained – Production, Properties, and Benefits

TPO is Thermoplastic Polyolefin, and it is one of several single-ply roofing systems.

The following will help you understand the composition, properties, and production of TPO membranes for both commercial and residential structures.

• A TPO membrane may be produced by calendering with lamination (this is the process of combining materials at high heat and pressure by passing them through rollers), extrusion with lamination (a process to make long shapes with constant cross sections, similar to squeezing toothpaste from a tube), or through extrusion-coating techniques.
• Sheet thickness is usually 40 mils to 100 mils. That’s about the thickness of a heavy duty trash bag.
• Sheets are typically produced in widths ranging from 6 feet to 12 feet.
• The composition of TPO sheets is a blend of polypropylene, ethylene propylene polymers, and polyester reinforcement.
• Overlapping seams are sealed by heat welding which uses hot air.
• The majority of TPO membranes are white but can come in a variety of colors.
• TPO roofing is resistant to oils and chemicals carried by commercial exhaust vents.
• TPO roofing material contains flame retardants and UV absorbing elements.
• TPO roofing systems receive high wind ratings when properly installed.
• TPO roofing has a life expectancy of about 30 years, however, only having been in use for three decades, its full potential lifespan is still being evaluated. As time passes, production of the system and its method of installation have naturally worked out the bugs, thus improving the product and increasing its longevity.

TPO Roofing Installation and Warranty

The installation of a TPO roofing system, when done by an experienced roofing company, is fast, clean, and virtually nonintrusive.

How your roofing system is installed will determine its ability to withstand the elements and ultimately its lifespan.

Affixing the TPO membrane is accomplished by making it fully adhered, and mechanically attached or ballasted; the following factors greatly influence the quality of the roofing system’s installation:

• Proper roof slope for a efficient draining.
• Strategic installation and fastening of insulation (when used) to deter bulging or sagging.
• Proper application of adhesives.
• Proper use of a seam welder (to prevent future leaks in the seams).
• All welds checked using a seam probe.
• Drip edge seamlessly connected around the perimeter of the roof.

In addition to a quality installation, a strong warranty is advantageous and very valuable. There are two warranties to consider when installing any new roofing system:

Manufacturer’s Warranty – This warranty covers manufacturing defects in the material used for your roofing system. Once the installation is complete, your contractor should provide you with a warranty certificate.

An example of material failure would be the separation of the lamination from the TPO membrane during hot weather. Unless it is determined to be a result of faulty installation, a claim should be made against the manufacturer’s warranty.

Contractor’s Warranty – This warranty covers the workmanship and installation of your roofing system.

While there is no industry standard for the duration of a contractor’s warranty, it should contain the following:

• A list of what items are covered.
• What actions or situations would void the warranty.
• When the warranty expires.

The above installation and warranty information underscore the necessity to thoroughly vet contractors.

TPO Roofing Cost

Pricing any roofing system can be a daunting experience. Often there is a significant disparity from one quote to the next, validating the need to collect a minimum of three bids from reputable roofing contractors.

Prices for installing a TPO roof system will vary depending on the time of year, brand, quality of the materials, method of installation, and the amount of labor involved. You can expect to see price quotes in the following ranges:

Tear-off costs can run between $100 and $200 per square. In some cases, the contractor will bundle this into material and installation pricing.

A tear-off is when the existing roofing system is completely removed to install a new system. Depending on the type of roofing system being installed and the condition of the existing roof, the new system may be installed over the existing one.

TPO material will see a price range between $150 and $500 per square.

TPO installation labor costs will range from $500 and $900 per square.

Maintenance contract pricing varies from contractor to contractor.

Roofers and their suppliers price materials in terms of ‘squares,’ whereas
1 square = 100 square feet.

So as an example, the price range of the bids you receive, including tear-off, material, and installation for a 1,000 square foot roof may fall within $7,500 to $16,000.

Note: Across the industry, roofing installations are more expensive in the spring and summer time. To save money, try to schedule an installation for the off-peak season (early spring and fall).

TPO Roofing Problems

The majority of problems that arise with TPO roofing systems occur as a result of poor installation.

Here are some commonly reported issues:

• Roof slope is too low, resulting in pooling water. (which degrades materials faster)
• Insulation (under the membrane) not installed correctly and is causing bulges.
• Seam separation from improper welding, allowing water penetration.
• Torn membrane from debris striking the roof.

For proper installation, it is essential to hire a roofing company that has extensive training and experience with TPO roofing systems.

People Also Ask

Question: Is TPO better than EPDM?
Answer: Inconclusive. Depending on which aspect of the two roofing systems you wish to compare, and your roofing requirements, the answer may vary.

While EPDM and TPO offer very similar benefits, TPO with its stronger and more durable seams (adhered to the roof), make it a desirable option.

Question: What is the difference between PVC and TPO?
Answer: Visually, the two roofing systems are virtually identical.

Performance-based, the two systems produce similar results until puncture resistance, environmental impact, and eventual “known” problems are taken into account. In this scenario, the TPO system is a superior option. However, when price and warranty terms are considered, PVC edges out TPO. Both are great products that check different boxes and satisfy different needs.

Question: How long has TPO roofing been around?
Answer: Since 1989.

Question: What colors does TPO roofing come in?
Answer: Standard colors are white, tan, and grey. However, TPO can be found in different shades of grey, brown, green, red, tan, and gold.

Question: Is TPO roofing flammable?
Answer: Yes. However, as with all roofing systems, TPO roofing is required to meet FM and UL fire ratings.

A distinct difference and advantage of TPO is that it does not release dioxins when burned and contains flame retardants.

TPO Information Revealed

When being presented options and quotes for new roofing systems, property owners frequently ask “What is TPO?” As you’ve discovered, it’s one of the most popular thermoplastic roof membranes in today’s roofing industry.

In this article, you were presented valuable information about the installation, warranty, cost, life expectancy, problems associated with TPO roofing systems, and answers to frequently asked questions.

By asking the right questions and being informed when selecting a roofing system and the contractor to install it, you will benefit from getting the best roofing solution and warranty at the best available price.

Sources:
http://www.everybodyneedsaroof.com/thermoplastic-membranes
http://mrca.org/aws/MRCA/asset_manager/get_file/161617?ver=344
http://firestonebp.ca/roofing/tpo-roofing-systems/tpo-installation-methods/
http://www.nrca.net/
http://www.azsfb.gov/sfb/Performance%20Specifications/Roofing%2009202018/07%2054%2023%20-%20TPO.pdf

See TPO Roofing System Explained for the first version of this content.

Do you know the blatant and hidden roofing job signs most likely leading to expensive repairs and/or roof failure? Most roofers won’t tell you about these common mistakes, but we will.

For the investment that a new roof requires, you would like to be able to expect a complete and mistake free installation. Avoid the expensive surprises and premature roof failure by knowing what to look for and can go wrong.

atlantacommercialroofingcontractors.com gathered a list of the 15 more common mistakes roofers make during the installation process.

Mismatched Roofing Shingles

One of the more visible mistakes a roofer can make is to use mismatched shingles. This obvious mistake occurs when a roofing contractor uses multiple dealers and purchases supplies from more than one supplier.

This can be avoided by selecting a roofing contractor that consistently uses the same roofing supplies distributor.

Layers of Shingles

Depending on the municipality your property is located in, it may or may not be unlawful to install a new roofing system without first tearing off the old one.

By tearing off the old roofing system, your contractor can fully inspect your roof deck for any weaknesses, gaps, and other potential issues. An added benefit is that your roof deck will not have to support the weight of two systems.

On the contrary, some commercial roofing systems are engineered to overlay an existing roofing system. Before this happens, the number of layers is checked and decking is tested for it soundness.

This cost-savings method prevents a complete tear-off and related debris hauling process, but should only be used on a commercial roofing system and in accordance with all local and state laws.

Incorrect Use of Roofing Nails

Roofing systems that utilize nails to secure it to the roof deck have specific guidelines for the size and use of nails. The following are common mistakes that could lead to your insurance company refusing to pay a claim in the event of roof failure.

• Nails without barbed shanks.
• Nails are too short.
• Nail Heads are too small.
• Not enough nails used. (the average is four per shingle and six for higher slopes or premium installations)
• Nails driven above the self-sealing strip.
• Nails driven into knotholes or gaps in the roof deck.

All of the above can result in the acceleration of a roof’s deterioration.

Incorrect Shingle Overhang at the Eves

Shingle overhang at the eaves should be between 6 and 10mm. More than this can result in the shingles being blown off during high winds or severe storms. Less than 6mm can result in water infiltration of the roof deck and leaks within the structure.

This mistake can be avoided by proper shingle installation and with the addition of a drip edge flashing to protect the edges of the deck from water infiltration. This flashing can be secured with a shingle adhesive.

Neglecting the Installation or Reusing the Drip Edge Flashing

Drip edge flashings help ensure a roof’s success at keeping the outside elements outside. Here are some of the benefits:

• Stops wind-driven rain from gaining access at the edge of the roof.
• Provides a surface for water to drip from which prevents saturation and decay of the deck or fascia board
• Drip edge flashings stop insects from entering the attic.
• Since they extend slightly past the edge of the roof, they support and keep shingles from sagging or breaking.

When replacing your roofing system, ensure that all drip edge flashings are replaced. This expense is minimal considering the cost of a new roof, and serves to protect your investment.

Improper or Missing Starter Shingles (Starter Strips)

Both rookie contractors and do-it-yourselfers frequently make this mistake. A starter section of shingles should be laid along the eves.

Without starter shingles, water will make its way to the roof deck through the cutouts of the bottom shingles.

Improper Installation of Underlayment

Roofing underlayment is a layer of water-resistant or waterproofed material that is installed directly onto your roof deck. The underlayment is applied under all other roofing materials as an added layer of protection from severe weather and the elements.

There are three principal types of roofing underlayment:

• Asphalt-saturated felt
• Non-bitumen synthetic underlayment, or synthetic underlayment.
• Rubberized asphalt underlayment

Asphalt-saturated felt, and synthetic underlayment are both water-resistant, while rubberized asphalt underlayment is waterproof.

Neglecting the Attic

Your roof is a system made up of various parts, including the attic space. Without proper attic ventilation, moisture can build up over time causing your roofing system to prematurely wear out, and ruining your insulation, resulting in sharp increases in your energy bill.

Improper Roof Slope

The use of materials that don’t suit the slope of your roof will leave your structure susceptible to water penetration.

As an example: For an installation of asphalt, wood, or tile shingle roofing systems, it is recommended to have 4 units rise per 12 units of run.

Roof Gutter Sag

Roof gutters are vital to guiding water away from your roof. When they sag, come loose, are installed too low, or do not sufficiently slope, they can back up or overflow, allowing water to enter the structure.

Insufficient Securing of Roof Valley Flashing

Since roof valleys typically handle large volumes of water runoff, they are more prone to leaks. When roof valley flashings are improperly installed, the roofing system can buckle, leading to water leaks and costly repairs.

In addition to the proper installation of roof valley flashing, using the appropriate amount of sealant and adhesive material will work to prevent water penetration.

Not Planning for Ice Dams

In colder climates, ice dams form at the roofline which forces water under the shingles. Thawing and refreezing can wreak havoc on a roofing system without proper insulation.

Damage can be significantly reduced or prevented by applying an additional underlayment from the roofline to about three to four feet up the roof. This provides an extra layer of protection from melting ice water.

Ignoring the Manufacturer’s Guidelines

Roofing manufacturers have detailed regulations on how their roofing systems must be installed. Deviations from these regulations may determine whether a manufacturer will honor their warranty in the event of the roof’s failure before the guaranteed lifespan.

Skipping the Roofing Permit

Most municipalities require a permit for new roof installation. The building owner or property owner is ultimately the one held liable for failing to obtain a permit.

Having a roof installed without a permit may result in fines, refusal of insurance coverage, or even the forced complete removal of the new roof.

Insufficient Roofing Contractor Insurance

If your contractor does not carry enough insurance to pay for damages or injuries, you may be held responsible for covering these costs.

All reputable roofing contractors will willingly provide proof of their insurance policy. Likewise, their insurance company may be contacted to confirm their coverages.

Avoid a Bad Roofing Job

Knowing the signs of a lousy roofing job and contractor will help you avoid expensive surprises and premature roof failure.

In this article, you discovered 15 of the most common roofing mistakes that can lead to leaks, weather damages, and roof failure.

If you don’t know what to watch for during the installation of your new roof, you are leaving too many windows for mistakes that can cause serious damages to your property and potentially result in the failure or loss of your new roof.

Sources:
https://www.fema.gov/media-library-data/20130726-1706-25045-9347/chapter8.pdf
https://dopl.utah.gov/licensing/contracting_avoid_costly_mistakes.html
http://www.ashireporter.org/homeinspection/articles/don-t-miss-the-shingle-stagger-/1973
https://www.handymantips.org/major-roofing-mistakes/

See 15 Common Mistakes Most Roofers Won’t Tell You About for the first version of this content.