Sagging commercial roof with multiple areas of ponding water present.

The average lifespan of a commercial roof varies from 10–40 years, depending on the materials used to construct it and how well it’s maintained.

But that doesn’t mean that a newer roof can’t become damaged or start to sag. In fact, much to a business owner’s dismay, many people find themselves facing a sagging roof sooner than they’d like.

If the roof of your commercial building is sagging, this article will cover the topics you need to know, including potential causes of a sagging roof, how a sagging roof can be fixed, and the cost of repairing a sagging roof.

What Causes a Sagging Roof Line?

There are several issues that can cause a roof to sag. The following are the most common causes of a sagging roof on a commercial building.

Water Damage to Ceiling Joists

Nothing is quite as exposed to the elements on a commercial building as its roof. The roof sees it all: wind, rain, snow, hail.

Over time, this constant weathering can have negative effects on a roofing system (which is especially true if the commercial roof is not well-maintained).

Ponding water on a commercial roof is especially damaging. If there isn’t a proper drainage system, ponding water can result in a sagging flat roof. It can also lead to leaks and more serious structural damage if the water freezes and sits too long on the surface.

Water damage to your roof can also lead to mold and mildew and rusted nails. It’s especially important to address water pooling on a sagging flat roof since pooling is more common with this type of roof. Eventually, this will severely affect your roof’s structural integrity.

Age and Lifespan of the Roofing System

With proper construction and installation, you can expect the roof of your commercial building to last anywhere between 10–40 years. A roof older than that is susceptible to the sagging that comes with old age.

If your sagging roof is older than 30 years, exploring a full replacement (rather than a repair) might make more financial sense.

Too Much Weight on the Roofing Material

A commercial roof can begin to sag due to excess weight. In colder climates, heavy snowfall and ice accumulation can lead to a sagging roof, especially if the roof was not installed properly.

If the roof of your commercial building sees a lot of snow, make sure to clear excess amounts of snow before the large amount of weight becomes a problem. Remember too, there are many ways to winterize the roof of your commercial building to help prepare it for a heavy snow season.

Poor Installation or Subpar Roofing Materials

The installation of your commercial building’s roof factors into its overall integrity. Poor installation can lead to a sagging roof in just a matter of years. The materials used in the construction of your commercial building’s roof can also play a part in a sagging roof.

It’s important to hire a licensed commercial roofing professional to install your building’s roof. A licensed roofer will know the correct way to install a roof for a commercial property, as well as the best quality materials to use.

How to Fix a Sagging Roof

The first step in repairing a sagging roof is to figure out what’s causing the problem. Walk around your building and see if you can assess the damage. If necessary, safely get on top of the roof and take a look around.

You should also inspect the foundation. If the foundation of your commercial building is settling, it may affect your roof, as well.

Once you have identified the cause of your sagging roof, you can begin to take steps to repair it. Here are a few solutions for repairing a sagging roof.

What to Do if There’s Water Damage

If your commercial building’s sagging roof is due to water damage, you first must find the source and address it.

Find out if your roof has proper drainage. Water should divert from the roof via metal flashings and gutters. If water has damaged the shingles or other roofing elements, make sure to replace those to prevent any further damage.

If a damaged gutter is an issue, repairing it before the damage gets worse is essential. Once you repair the gutter system, you shouldn’t have further problems with ponding water on the roof.

What to Do for Damaged/Missing Materials

In some cases, commercial roof damage is superficial and can be fixed with a simple repair. Assess the damaged materials (shingles, decking, trusses, or rafters are common areas of damage with a sagging roof). A commercial roofing company will easily be able to repair any common superficial roofing issues.

Sagging Roof Repair Cost

The cost of repairing a sagging roof varies. There are many variables that factor into the cost: material, size of the roof, and the extent of the damage.

Smaller projects like repairing cracked shingles will cost less, while a full roof replacement often ranges between $8 and $20 per square foot (again, depending on the condition of the roof deck, joists and materials chosen for replacement).

We ALWAYS recommend performing regular roof inspections to address small problems before they cause significant roof damage. Routine inspections can make the difference between minor repairs and needing a completely new roof. (This is particularly important if you live in an area that sees heavy snowfall or other severe weather.)

TEMA Roofing Services: Reliable Commercial Roof Repair

Hiring a roofing contractor for your commercial roofing repair needs is a smart choice. At TEMA Roofing, we are well-equipped to tackle sagging roof repair projects, as well as any other needs your commercial roof may have.

From small repairs to full replacements, we bring over 50 years of experience to every job. Our team is fully licensed and insured for your peace of mind, and we’re a proud, verified member of the National Roofing Contractors Association.

Don’t ignore the warning signs! Whether your commercial roofing project is large or small, we’re here to help. Contact us today for a free consultation.