A flat roof is the easiest type to build and offers perks you don’t get with a sloping roof.  For one, it’s a potential garden area.  It also gives you a place to put your lawn chairs, hang out in the sun and gather with friends. Additionally, it’s easy to walk on, simplifying maintenance and repair.  The biggest drawback is the potential for leaks. Most flat roofs aren’t actually flat.  They slope slightly to one side (a 1/4-in. per foot is considered minimal) to allow drainage.  After a heavy rain, puddles are inevitable.  The longer water stands, the more likely it is to find a way through the roof covering.  Still, a flat roof shouldn’t leak for many years.  But warranties don’t mean much without proper maintenance.

Flat Roof Maintenance

The whole point of roof maintenance is to prevent leaks.  You can avoid leaks if you do the following regularly:

Keep the drains clear

You’ll find the drain openings in the barrier on the downward-slope side of the roof. When they’re blocked by leaves or other debris, water pools on the roof.  Clear the drains by pulling gunk out of the openings in the raised sides and putting it in a bucket.  Do this at least once every month or two, more often in the fall when leaves fly around. While you’re at it, clear out the downspouts with a garden hose.  Dirt and silt can stick in the drain openings and clog the downspouts. That’s less likely to happen if the roof is clean.  Regular sweeping is another bi-monthly task.  Collect the sweepings in the bucket and bring it all down from the roof when you’re finished.

Prune overhanging branches

Branches that touch the roof can scratch and damage the covering.  Those that aren’t actually touching the roof can break off and fall during a storm, also causing damage.  Branches are also sources of leaves, seeds and small twigs that can block the drains.

Roof Inspections

Most flat roofing systems have seams.  While you’re cleaning debris, check the seams for signs of lifting or separating.  Even small cracks can cause leaks and should be repaired promptly.  Check also for blisters that occur when air is trapped underneath the membrane.  They need to be “popped” to let the air out, then patched with roofing cement or overlaid with a patch of the same roofing material.

Inspect the flashing

Flashing protects plumbing stacks, roof vents and other protrusions to prevent leaks.  Look for cracks or gaps that could allow water to seep in. Repair and cracks with roofing caulk.

What Is Roof Maintenance?

It refers to any kind of work done on a residential  roof in order to prevent wear and tear.  Flat roof inspections need to occur twice a year, or after a big storm, to determine if anything needs to be fixed or replaced.

A general flat roof inspection and maintenance should include the following:

Look for Debris

Some debris can be found on a roof usually after a storm.  Debris can scratch, puncture or cause serious damage to your roof so it needs to be removed immediately.  You should inspect for any visible damage when removing debris.

Repairing Seams & Membranes

Seams are where 2 pieces of roofing material are adjoined.  Both seams and membranes can be vulnerable to leaks, specifically in places on the roof that have accessories built into it such as air vents, skylights and air conditioner units.  The sun’s harsh UV rays can also break down the membrane overtime, causing cracks to form.  Any seam or membrane that is damaged or rendered ineffective needs to be repaired immediately to prevent further problems.

Replacing the Flashings

Flashings are installed into areas of the roof where where two opposing surfaces meet such as parapet walls.  These areas require the extra protection that flashing provides. They help prevent water from leaking through the vulnerable areas.  Over time, flashings can become loose or deteriorated from excess exposure to moisture and will need to be replaced.

Clearing Clogging

Clogging may occur in drains, vents and scuppers,especially after storms.  Scuppers allow water to run off the roof, directing water to flow from the side of the roof down into a drainage system.  All drains, scuppers or gutters need to be kept clear.

Plumbing Stacks

Plumbing stacks are pipes on the roof that direct air flow into the building’s plumbing system.  Check that they are clear of obstructions and properly sealed.

Look for Blistering

Check for leaks and blistering – blistering is roofing spots that are raised and spongy/soft looking.  They happen when air is trapped between the layers of felt or the felt substrate.  If a blister ‘pops’, then water can enter through and damage roofing material.

Check for Ponding

Ponding is standing pools of water that sit on your flat roof and are unable to drain or dry out.  Some ponding that has eventually dried out will leave a concave area with a water mark or dirt ring surrounding it.  If you notice these marks, then it means that your flat roof ponds regularly, and a proper drainage system may need to be installed to prevent further damage.

Check For Splits & Cracks

Splitting and cracking of roofing material can be caused by weather changes, added stress or pressure, ponding or simply poor workmanship.  Any area that is cracking or splitting needs to be filled.

Fill Pitch Pans

Pitch pans protect and encase supporting connections roof penetrations.  They are filled with “pourable sealer,” a more environmentally friendly material and easier to work with than the previously used “pitch”.  Though they are simple to build and fix, pitch pans play a key role in maintaining the overall health of the roof because they seal out water in vulnerable areas.  So they must be kept cleaned and filled.

Flat Roof Repair

There are several flat roofing systems in common use.  When leaks occur, you can repair most with a patch of the same material as the roofing.  For materials like modified bitumen (similar to asphalt roll roofing), apply the patch with roofing tar. Other materials, like EPDM rubber, TPO (a type of plastic) and PVC (another plastic), need to be heat-sealed.

EPDM roofs tend to be the most DIY-friendly to repair using a heat gun and/or adhesives.  But TPO and PVC roofs are trickier and best left to pros.  The best decision for roof repairs is to call a Professional.

Pinpointing a leak can be challenging because water may seep under the membrane for a considerable distance before finding a path through a seam. Here’s a savvy way to go about it:

Go indoors, note where water is dripping or the roof decking or drywall is discolored, and measure the distances from that spot to the walls on either side.  Use those measurements to pinpoint the same spot on top of the roof.  Then proceed sideways or along the upward slope until you find the damaged seam or deteriorated section.   If that doesn’t identify the spot of the leak, you may need an oversized patch that covers all the likely spots where water could enter.

Flat Roof Replacement

When the roof covering exceeds its warranty period, it’s time to think about replacement.  But if you notice any of the following conditions, replacement should happen sooner than later:

• Damage to the membrane, seams or flashing in several places;

• Multiple leaks;

• Water habitually pools in certain areas;

• There’s impact damage from a fallen tree branch or other debris.

Leave roof replacement to the Pros.  They’ll remove the old membrane, rotted plywood and fascia, damaged roof vents and plumbing stacks.  They may also replace insulation.  After cleaning up, they’ll lay a new membrane, re-flash all the vents and install new perimeter flashing and fascia.