Flat Roof Problems to Watch for in Spring and Summer

Jan 27, 2026

Jamie Unruh

With regular maintenance, flat or low slope roofs on residential or commercial buildings can last over 20 years in Alberta’s climate.

Our Two Main Types Of Roof Systems

There are two types of flat roofing systems that we commonly install.

First is the SBS (Styrene Butadiene-Styrene) AKA torch-on roof system, which most flat roofing companies can install.

This system uses a base sheet (the SBS) put on top of the substrate followed by cap sheet (also SBS that’s covered in ceramic granules), with the overlaps in the membrane staggered between the two layers. The two layers are thermally fused together usually with the use of a propane torch however there are “flameless” systems available that are self-adhered and use a hot air welder to fuse the overlaps and details together.

There is a thin poly film on the surface of the base sheet that when heated burns away and allows the two sheets to melt together. A sign of a good seal is a little bit of bleed out (black goop) between the seams. Too much bleed out means the SBS has been overheated. Just a little bit of squish between seams is all you need.

The second type of roofing is one that very few companies offer and one that Beyond specializes in - a SPFRS (Sprayed Polyurethane Foam Roof System).

This system uses 1.5 inches of closed-cell spray roofing foam followed by two coats of silicone that’s imbedded with ceramic granules.

The foam used in this situation is a higher density of foam than what is typically used in homes, and as long as the coating remains intact and the foam underneath is not exposed to UV rays, the roof is fully renewable. This system comes with a 10-year warranty and annual inspections. If the foam is protected, it will last forever, but the silicone and granules will need to be redone every 10 -15 years to maintain that permanence. Upon re-coating, the warranty is renewed.

Due to the nature of the foam, these roof scan only be installed in warmer months, typically May to October in Alberta.

The spray foam roof system is typically more affordable in the long run as the foam is permanent, and only updates on the silicone coating are required. This installation is also quicker than traditional roofing systems and it provides an additional R 9 of insulation value to the roof.

"If the foam is protected, it will last forever"

Spot the Rain Drops

Whether you have a SPFRS or SBS roofing system, there are things you should look for when doing your annual walkthrough.

The first thing that comes to mind is water coming into the dwelling. Leaks, ceiling stains, moisture inside light fixtures and the like are all indicative of a possible roofing concern.

In Calgary, depending on the style of house you live in, you could be looking at an attic rain issue, or you could be looking at roof leaks. Conventional attics can have leaks or develop attic rain. With a flat roof, if you're starting to see water coming into your house, chances are you have a roof leak.

Standing or pooling water on a flat roof can shorten the lifespan of most roof systems, but it is generally not a concern for leaks as long as it’s on the outside of your home.

Mold is another issue in flat roofs. If found above the vapor barrier, mold is not a threat to the home, but it’s good to look for structural rot that might be starting in the beams.

However, once the time comes to re-roof the building, crews can inspect the roofing structure to see if there’s an opportunity to correct a slope.

Lost My Rocks

Granule loss is another problem that can pop up. Of course, the older the roof the more likely the granules will wear off, but it’s rarely an issue if you give your roof a once over every now and then.

Granules on a SBS torch-on roof can dissipate over time – a long time, but checking on it every couple of years or so is a good habit.

Installing a SPFRS (foam) roof with Beyond will include a warranty along with an annual inspection which means our crews can spot any issues and deal with them well ahead of when they might become a real problem.

Tender and Soft, But Not in a Good Way

Soft spots are another indication that water is getting into the roof system. Some flat or low slope roofs also have insulation between the roof membrane and the roof deck which is accompanied by a vapor barrier. Although rare, sometimes water can leak into the insulation and pool on the vapor barrier or stream along the barrier without getting into the building. This will cause wood to rot in the roof deck and create a soft or spongy spot on the roof. The insulation can also be compromised from the water and would also need to be replaced.

A recent flat roof job that Beyond Group took on saw faulty construction by a not so professional professional that required much more repair than the homeowners initially thought. The wood deck of the roof was rotten in a large area of the roof. The rot had to be ripped out and replaced before the new torch-on roof could be installed.

"checking on it every couple of years or so is a good habit."

Preventative Maintenance

There are a few options that homeowners can do for preventative maintenance, but they come at a cost and usually it’s not a necessary investment.

Installing a flat roof system costs 3 to 4 times more than a traditional shingled roof because a flat roof needs to be watertight whereas a shingled roof is meant to shed water away.

Homeowners should take the time to visually inspect their roofs and look for things such as blisters, open seams or the metal work failing at the perimeter, which can happen occasionally after a windstorm.

Industrial building owners should also keep an eye out for splits and cracks in the roof caused by building torsion. This is usually only something that can happen in larger, say a 50,000 square foot warehouse, when shifts in the ground affect the foundation causing bending in the structure which then translates up to the roof system in the form of cracks or splits in the roof.

A Job Worth Doing is Worth Doing Well

Like most jobs, if it’s done right the first time it’s going to last along time. Beyond is dedicated to ensuring our clients have the best solutions for their needs. Spray foam roofing is one job we do well, and efficiently. Give us a shout today to learn more.

"dedicated to ensuring our clients have the best solutions for their needs"

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