How do you repair a flat roof?

flat roof repair

Flat Roofing Services and More

It’s raining! It’s pouring! The flat roof is leaking! As an owner or manager of a commercial building, the last thing you want to find out is the roof has a leak. You’re probably asking, “Why is my flat roof leaking?”, and in this piece today, we will talk about that and some other issues about flat roof repair.

What To Do With Your Flat Roof

Most commercial structures have a flat roof and for several reasons, like installing the HVAC system on the roof, more usable square footage inside the building, and flat roof repairs are easier than on a pitched roof.

This doesn’t mean they are beyond having issues though. Like any roofing style, a flat roof will have leaks, and there are three prime causes. Depending on the damage from these potential cause, the roofing contractor will advise if flat roof repair or replace is the better choice. The three probable causes are:

  • PONDING WATER: Ponding water on a flat roof is when water remains on a roof (after a rain) for more than 48 hours. A flat roof isn’t flat, they have some slope toward drains. If the drains become clogged, that water has nowhere to go, and that creates ponding. A monthly inspection is recommended just for that purpose – checking, draining, and ponding. If clogged drains are caught in time minimizes flat roof repair needs.
  • DAMAGED MEMBRANE: Flat roofs use to be constructed as built-up roofing, where multiple layers are used that include asphalt, tar, gravel, and roofing felt. While this type of flat roofing was effective, it took longer to install, and that made it more expensive. Today, a flat roof membrane has become the preferred choice. It is 3 ply thinner material that is more durable and flexible, which makes installation easier and less expensive, yet more effective than the old built-up style.
  • Still, this membrane is susceptible to blistering, cracking, and punctures which make the insulation vulnerable to getting wet, and once it is wet, it isn’t effective and other leaks form. This is another reason a flat roof needs monthly inspection to check for the blisters, cracks, and punctures. Getting flat roof repair as soon as possible, minimizes roof leaks.
  • PENETRATING STRUCTURES: Flat roofs and slope roof both have penetrations with the HVAC, pipes, and vents.  These areas are vulnerable to leaking. There are a variety of tactics used to prevent this, such as boots, collars, flashing, and wraps. However, these can become vulnerable after exposure to the climate and elements. If a monthly inspection is missed, or the inspection doesn’t find one of these in need of replacement, you can expect a flat roof repair.

Do flat roofs always leak?

When you have leakingflat roof, repair in rain isn’t something you want to do, so the best thing to do is take preventive measure so that you don’t have a flat roof repair to deal with in the rain. While a flat roof is unique and has some significant benefits, it takes some maintenance to keep it healthy and leak-free.

The reasons that may cause a flat roof to leak could be any of the following:

  • Alligatoring–When a flat roof is built using asphalt, as its ages, it loses its elasticity then bubbles and cracks, looking like alligator skin. When a flat roof membrane gets to this point, flat roof repair isn’t possible.
  • Leaking & moisture – Moisture that is left to linger on a flat roof is one of the most common causes of leaks. The moisture sits and seeps through the membrane, if there are any bubbles or cracks, it has easy access. Once the moisture is under the membrane, it will begin to leak. If this isn’t caught early enough, not only is fungus and mold possible, but the damage caused may make a flat roof repair impossible, leaving you to get a total roof replacement.
  • Buckling Membrane – Flat asphalt roofs and slope roofs are constructed similarly in they both use a membrane that has been soaked in asphalt. It is then laid on the building top in one piece on a commercial structure. Over time, the building will shift with the ground, the roof will contract and expand, and that can cause buckling in the membrane.  That buckling allows moisture under the membrane, then the damage can be extensive enough flat roof repair isn’t possible.
  • Missing Flashing – Flat roof contract and expand with the temperature and weather. The metal flashing used on the roofing edge and penetrations can loosen with that movement.  This leaves a vulnerable area for moisture to enter and begin damage that goes beyond flat roof repair.

How do you stop a flat roof from leaking?

Whether you are the owner of a commercial building or the maintenance manager, you need to find and keep a product on hand when flat roof repair for those rainy days. You can find flat roof repair coating to apply for a temporarily stop a leak at any hardware store.

flat roof repair

What is the best material for a flat roof? and What is the life expectancy of a flat roof?

The four most popular choices and their life expectancy are:  

  • PVC Roofing – The most expensive but the benefits outweigh the cost with the durability and a life span of 20 years.  
  • Metal Roofing – This material has a long lifespan of 20 to 30 years, longest of all the flat roof materials and is the most durable.
  • TPO – With heat welded seams, this material is less likely to leak and has a lifespan of 10 to 20 years.
  • Modified Bitumen – The budget friendly flat roof material with the shortest lifespan of 10 to 15 years.

Final Thoughts

Flat roof repair isn’t something any commercial building owner wants to deal with, and with proper inspection and maintenance, the chance of leaks if minimal.