When a roof becomes damaged and starts to leak, there is a great deal of execution and planning that goes into it’s repair. If you have a flat roof that needs to be repaired and you want to save money on doing so, keep reading. If you’re a contractor looking to open new doors for service sales, keep reading.
Once upon a time, I was responsible for the maintenance of a commercial building that had developed a flat roof drainage leak. When I inspected the problem, I learned that the leak was causing water ponding. The water began to seep into the building and onto an expensive piece of machinery. Even if the leaks was fixed, the building would have still been at risk for mold. Once there’s mold, the costs of fixing the problem skyrockets. Mold creates a toxic environment for the building’s employees and an OSHA nightmare for the employer.
So I was confronted with a flat roof repair that could not wait.
Many handymen look for shortcuts and will just rip off the existing roof and re-roof the area. This type of repair can be very expensive, and it can be a lot of unnecessary work. You’ve got to tear off the existing roof, remove the sheathing down to the joists and secure new ones to the old damaged ones, repair & repaint the interior ceiling etc etc. Time and cost. Plus in the end, the amount of sheathing and roofing that’s replaced is way larger than the actual area where the roof ponding is occurring.
At some point, you have to address the root of the problem or the water just keeps coming back. The longer that water just sits there before the sun can evaporate, the more damage it can do. This is a problem that is all too common for flat roofs. I’ve been roofing for over 30 years and I’d say honestly I see water pools on about 75% of the roofs I get on. In this particular case, the client didn’t have the budget for a re-roof, so that was out of the question anyways.
Some contractors will cut out a few feet beyond the low spot and cut pitch strips to nail on the joists to level out the areas. The problem is, it’s tough to get the strips just right to fully eliminate the pooling area. You’ll end up just creating another pool in a different area.
I decided to try a roof leveling compound. In the same way self leveling mortar was used on decks, I was going to try it on a roof. No demolition, no cleanup. At the time I had been experimenting with crumb EPDM/ EPS mixed with a polyurethane adhesive to create a compound to fill the rolled curb on my driveway, creating a ramp so my wife’s car wouldn’t bottom out every time she exited the driveway. I thought the same basic ingredients could be applied here. It was certainly much lighter than concrete mortar. Over the years I experimented with different ingredients and different amounts and eventually what I call GreenSlope came of it. (The “green” in the name because the contents were primarily made from post-consumer recycled products.)
Here’s the process:
- Clean the area thoroughly to ensure the primer gets a good bond before priming the area
- Mix the crumb rubber (EPDM) and EPS (expandable Polystyrene beads) with the GreenSlope adhesive using a bucket or bag and pour it out over the area
- For small ponding areas (3’x3’, a 5 gallon kit can be used. For larger areas, at least one tote is recommended. (Formula: Length (ft) x Width (ft) x Depth (ft) x 1.34 = the # of buckets you need)
- Trowel it on, while continually checking it with a straight edge and/or screed board while compressing the material to seal up any pores
GreenSlope can be used in a wide range of practical scenarios:
- To raise a low area at a scupper where the water pools instead of flowing off the roof
- Around HVAC units where the weight of the machinery causes a sink in the roof deck
- Near inner drains where the roof sags before it can reach the drain, the list goes on…
Well you might say, now isn’t the water just going to pool somewhere else? In some cases, yes. Sometimes GreenSlope simply disperses the water enough to areas where it can evaporate faster. A large, deep pool will remain on a roof for longer than 48 hours after a rain. When you spread the water over more surface area to where the pooling areas are less than ¼ inch deep, the sun can evaporate it faster so it doesn’t remain as long and cause problems.
When it dries, you can subject the area to a water test to make sure that no major pooling exists. If you missed a spot, allow the area to completely dry and make the necessary corrections. I like to topcoat it with an elastomeric coating to ensure full waterproofing. If you have any leftover GreenSlope adhesive, you can use that too.
Since my first experience with this type of fix I have repeated it many times over the years and let me tell you, building owners love it. This option takes a fraction of the time of the alternatives and no special handyman skills are needed. It will last for years and can prolong the lifespan of the roof substantially by eliminating water from problematic areas.
And you might say, well isn’t it better (for you, the contractor) to do a re-roof? After all, more man hours. Sure, you can make more with some of the other options. But cost of materials for this type of fix is so low in relation to those other jobs, you can charge way less than the alternative while still turning a good profit. Plus it opens all kinds of doors to speak with building owners and facility manager about taking preventative action to eliminate these problematic areas. You’re not going in there asking if they need a new roof, you are educating them about why the water sitting on their roof is a problem and how you can prolong the life of their roof years, saving them lots of money in the long run. You’ll stand out from the guys who are just looking for the big re-roof and believe me, when the time comes for that big re-roof job, you’ll be the one they call on first because you were able to fix this particular problem at a fraction of the cost the other guy quoted them at and by now you’ve developed a solid relationship with them.
So if you have a flat roof repair and are curious about whether our product, GreenSlope is a good fit for a job, feel free to email me at jon (at) greenslope.net and I would be happy to answer any quesitons you may have. If you’ve already tried our product and want to let others know about it, feel free to leave a comment below. Maybe I will set up a forum soon, but for now I gotta run. Roofs are calling!