Welcome to Family Roofing

CALL OR EMAIL US TODAY FOR YOUR FREE ESTIMATE – 202-276-5004   FAMILY.ROOFING@YAHOO.COM

 

At Family Roofing, we take great pride in our experience, expertise, quality and customer service. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. Our reputation is based on service, safety and quality, regardless of how large or small the job.

 

Common Causes of Metal Roof Leaks

Few roofing products offer the durability, strength, and performance of metal roofing.  That being said metal roofs aren’t indestructible and they can leak.  Even though a metal roof has a lot of pros over other roofing materials, due to its weather resistance and extreme durability, homeowners sometimes ask why their metal roof could possibly be leaking.  A metal roof should last between 40 to 70 years when properly installed, but a leaking metal roof could be the result of mistakes made during installation.

Below are common reasons even properly installed metal roofs can leak.

Metal roofing screws 

Roofing screws are responsible for the majority of leaks on metal roofs.  Metal roofing screws seal water out by compressing a rubber washer at the base of the screw head.  When the screw is driven into the metal roofing panel the rubber washer forms a “gasket” between the roofing panel and the screw head.  It sounds simple enough but several things can go wrong like under driving screws, over driving screws, driving screws at the wrong angle and screws that missed the framing member.

Over driven screws: In an attempt to ensure a tight seal between the metal roofing and the screw head many roofing companies will over drive the screw.  The unneeded torque breaks the rubber washer and tends to spin it out to the side.

Under driven screws: These are a result of not enough torque on the screw to properly seat the rubber washer to the metal roofing panel.  The rubber washer is never compressed and no gasket is formed.

Screws driven at the wrong angle: These don’t allow the rubber washer to sit flat on the metal roofing.  Part of the screw is sealed but part is not sealed.

Screws that have missed the metal strut or wood framing below: These have nothing to seal against.  These can be hard leaks to find as many times the screw is their but without touching it you wouldn’t know that it didn’t hit anything and didn’t seal.

Even if the screws were installed correctly with the right amount of torque it doesn’t mean that the rubber washer is safe.  Hot summers followed by hard cold winters are unkind to the rubber washers.  They degrade and lose their seal and it can be very difficult to distinguish which screw is leaking and which is not.

Stack flashings

Another area very prone to leaks on a metal roof is the area around stack flashings.  Stack flashings are the “boots “ or flashings around pipes that come out of the metal roof.  HVAC vents, air vents, and plumbing pipes all have to vent and come through the metal roof. The stack flashing is how the pipe is waterproofed.  Most stack flashings are rubber or rubberized material that sits flat on the metal roof and forms a seal but also “squeezes” around the pipe to form another seal.  The movement in the metal roofing from expansion and contraction is always testing these seals.  The sun also degrades the rubber flashings which last only about half the time of the metal roof.  The more caulking, sealant, or tar that is placed behind and around the stack the more they seem to pond water and leak.   Plan on replacing worn or rotten stack flashings in order to keep your home dry.

Stack flashings are typically made of rubberized material forming a seal around a pipe or vent. They have a lifespan which is less than half that of the roof. Due to the metal roof expanding and contracting in the heat, over time a lot of strain is placed on stack flashings. The best option, once they fail, is to have them replaced by a qualified roofing expert.

Missing Sealants 

Metal roof sealants that are installed in conjunction with a metal roof rarely last as long as the metal roofing panels do and need to be replaced with regular roof maintenance. Sealants under trims such as metal ridge caps and Z flashings, around roof transitions, counter flashings, reglets, and pitch pans will all need to be “topped off” from time to time as they wear. Use a metal roof sealant specifically made for metal roofing.  Other types silicone caulkings may not adhere to the paint on the roofing panel and trims.  Metal roofing goes through a daily expansion – contraction cycle and if any sealants are to last they must be able to remain flexible and stretch with metal without breaking their seal.

Typically, sealants are installed at the same time as your metal roof.  The problem is sealants don’t last as long as the metal itself and will need to be replaced from time to time. Checking the sealant should be a part of the regular maintenance routine for metal roofs, particularly around these areas:

• Metal ridge caps

• Z-flashings

• Roof transitions

• Counter flashings

• Reglets

• Pitch pans

It’s usually a good idea to have a roofing professional inspect the sealant in these areas and replace it as needed.  Only a sealant designed specifically for metal roofs should be used. Typical silicone caulking doesn’t always adhere to roof surfaces and may not maintain its seal through all the expanding and contracting which can occur with metal roofs.

Curb Flashings

HVAC units on metal roofs are usually sitting on curbs.  Installing metal roof panels is a relatively easy process but it’s the flashing that really test a metal roofers ability.  HVAC offer little room for error when fabricating the flashing and keeping a curb dry can be easier said than done.  The uphill side of curbs and the two upper corners of the curb flashing are difficult areas especially on lager HVAC units.  Water often gets trapped behind the unit and “stands “ behind the flashing which eventually erodes sealants and begins to leak.  The more you caulk, seal, or tar the uphill side the more water it will hold. This Catch 22 is difficult to remedy without removing metal roofing panels and starting over.

It’s fairly common for HVAC units to be installed on a metal roof.  In most cases, the HVAC will sit on top of a roof curb, which is a metal structure designed to both support the weight of the unit and offer a means for connecting the ductwork.  The area around a roof curb is one of the most common places for leaks to occur on metal roofs.  Flashing should be installed all around the curb, but even if this is done correctly, water can get through over time, especially on the uphill side of the curb.

Seams and Overlaps 

Seams where 2 pieces of metal roofing overlap each other often leak because of a condition called capillary draw.  Capillary draw is when water can actually travel uphill between two tightly joined pieces of metal.  Sealant or butyl tape between the two pieces of metal can break the capillary draw but if not used correctly can actually make leaks worse than if none had been used at all.  When your roof is first installed, it is crucial that overlapping panels are properly sealed.  To prevent any leaking at the seams, we apply sealant or butyl tape to seal joints and overlaps.  Because, over time, roof panels can shift and move, we recommend a regular inspection to make sure they haven’t moved and are still sealed.

When should you call a roofing contractor to repair your roof?

As soon as you notice the leak. The quicker you get the leak looked at the better.  You have no idea what hidden damage is being done.  If you have one leak, then chances are another potential problem is about to show up somewhere else.  The entire roof should be inspected when a roofer comes to take a look at the leak.