Got a leak? You’re not alone.
Even with routine maintenance, leaks are common on flat roofs. So how do you know when a flat roof needs to be replaced and when it just needs to be repaired? The truth is, it’s not always easy and straightforward. Ideally you’ll want to consult with a local roofing expert to assess the scope of your problems and determine the most cost effect solution for lasting protection. The decision to repair or replace your roof should be left to a professional commercial* (flat roof) contractor to perform the assessment. There are just too many unique complexities in flat roofing that you or a general or residential contractor may not have any expertise in. It may cost more but it’ll save you big bucks in the long run.
What is entailed in a roof inspection?
Check Seams, Flashings, And Attachment Points
Your inspection should include check for cracks at joints and corners, chimneys, HVAC units and ventilation points with special attention to any damage, deterioration, punctures, aging, leaks, and ponding water areas. They’ll probably perform a roof cut to asses the damage underneath the membrane. EPDM rubber membranes especially have a tendency to shrink and pull off parapet walls, drip edges and chimneys. Foot traffic is another common problem. Maintenance personnel like HVAC contractors might drop tools, walk over fasteners etc that can puncture the membrane.
Identify Water Ponding Areas
Water that stands on the roof for more than 48 hours can be very problematic. Ponding water – especially around seams, flashings, drains, chimneys, skylights, and parapets is one of the top culprits for leaks. Wet insulation can cause mold and structural damage, which can be even more expensive to fix than putting on a new roof. If your roof consistently retains pools of water after a rain, you really shouldn’t neglect it. Better to address the underlying (or lack thereof) problem.
When to Replace
Leaks don’t necessarily mean a roof needs to be replaced. Replacing a roof can be very costly and time consuming – a last resort.
So when do you actually need a replacement?
- If the original material installed has reached the end of its service life, you may need to replace the roof. The service life of a roof varies from about 5 years for rolled asphalt roofs, to 7-10 years for EPDM rubber membranes, to as long as 30 plus years on PVC membrane roofs.
- Improper installation is the other main reason you might need an install.
- PVC is a good option if you absolutely have to replace, due to it’s longevity. The downside: it’s probably the most expensive option. PVC roofs have welded seams that are impervious to moisture and nearly indestructible. It also reflects the sun’s heat, allowing you to save on energy costs.
- Another note: If you have a tar and gravel roof, finding the source of the leak can be a long shot. If your roof is leaking badly, it will most likely need to be replaced.
When to Repair
If your roof system has been installed properly and is still within its service life cycle, your best bet is to repair it. If you don’t want to make the repairs yourself, get a flat roofing contractor to help. If you are a DIY kinda guy/gal, there several repair options depending on the scope and your budget. Some flat roof products are specifically designed to deal with such issues and can be helpful in these situations. Roof leveling compounds like GreenSlope, a lightweight EPMD/EPS-based material, can be applied to the substrate to level out the low area and facilitate flat roof water drainage. These help by either a) raising the roof surface in low spots to allow the water to move towards proper drainage areas, and/or b) lessening the depth of the puddle to disperse the water over more roof surface area so it can evaporate faster. Depending on the extent of the issue and the size/depth of the ponding areas you might also consider installing tapered insulation under the membrane first and then fine-tuning over the top with a leveling compound like GreenSlope. This is a quick and inexpensive option. More Info >
If you have a single-ply membrane, be wary of using a roof coating. 1) They’re expensive, and 2) they tend to peel, chip and crack after a couple years. Plus, once you apply a coating, it becomes very difficult to repair if it’s still leaking.
To wrap things up here, regular Maintenance is KEY to roof longevity. Shoot for once a year, plus on a needed basis i.e. after major storms, rain, wind, snow, ice, freeze/thaw cycles, etc. When you do, be sure to:
- Check seams, flashings, and attachment points for wear and tear
- Remove buildup of debris (moss, sticks, leaves…) in/near inner drains, scuppers etc
- Identify problematic water ponding areas and make the necessary repairs
Alright, that’s all for now. Be sure to check back in for more roofing tips and info each week. Out.