Is Standing Water On a Flat Roof a Problem

The flat roof design is becoming more popular in skyscrapers and commercial buildings. Building owners won’t bother giving rooftops pitches of less than 0.5/12, as this can redirect water to the drainage systems. Pitch is the angle and slope of the roof’s roof for each 12 inches it is traversed. A pitch of 9/12 is very steep, and water can flow down easily. Pitch of 0.5/12 to 1/12 has a lower angle, which means water flows slower.

A flat roof can be a great advantage, but it can also lead to water accumulation at the top that can cause damage. Water can also build up, which can cause roof damage. The weight of water can cause damage to your home’s integrity if the roof’s supporting structures are not strong enough.

We will discuss in detail how water accumulated on flat roofs can cause long-term damage and permanent effects to your roof.

What is standing water/pooling water?

When water remains in an area and does not drain, it is called standing water. This happens most often during heavy rains or storms, when water accumulates for up to 48 hours. This can lead to roof damage if it is not addressed.

Although most building owners will blame the weather, in reality there are many man-made causes.

The roof does not have a pitch

Contractors and professional roofers know that flat roof designs should always have a pitch between 0.5/12/12 and 1/12 to allow water to flow towards one side.

Poorly designed roofs with clogged gutters

Many homeowners believe that roofs are more decorative, which can cause them to overlook the practical design of their roofs. Water can also build up on roofs due to clogged gutters. To ensure that water flows down the gutters, it is best to call a roofing professional.

Exceed materials at the roof’s edge

Roofs are designed to drain water and snow quickly and away from vital components of the house. Contractors and owners who are smart would be aware of this fact. However, excess roof materials can trap water and cause damage to your roof’s main purpose. This is something you should keep in mind as you work with a contractor to design your roof.


Sagging roof

Ponding is often a sign that your roof is starting to sag. This is an indicator that your roof is beginning to collapse under the pressure. You should immediately contact your local contractor if you notice signs of sagging on your roof. It’s only a matter of time before your roof falls.

Leaks are more common

Roofs are not designed to hold water. If water dries on your roof, it could eventually seep into your home through holes or passageways.

Organic growth on your roof

This can cause moisture to seep through the roof and into the interior of the house, which can lead to molds, mildews and mosses. These organic growths can gradually compromise the foundation of your home.

Roof materials will deteriorate quicker

Water seepage into material structures such as wood and natural slate tiles can lead to decomposition of wood and eroding slate tiles. You should be aware of the presence of granules in your gutters. This is an indication that erosion is occurring.


There are other ways to drain water from your roof if your pitch is poor.

  • Make sure your drainage system is wider so water can flow freely through more space.
  • You can add more passageways to allow water to flow through.
  • Sloping or pitching materials can redirect water flow to drainage areas.

Standing water on a flat roof can be a problem as rooftops are designed so that water is quickly drained away from any cracks or passageways. A pitch of 0.5/12 to 1/12 is best as it can drain water towards the gutters.

You don’t need to have any previous knowledge about installing gutters or removing water from your roof. It’s better to hire a professional roofing expert who specializes in maintaining your Florida roofing, removing standing water and replacing roofing material.

This post was written by Ted Williams! Ted is the owner of A Old Time Roofing which is the premier Clearwater Roofing Contractor! Ted is a Master Elite Weather Stopper GAF Roofing Contractor, a double award winner of Best Steep-Slope Contractor from GAF and achiever of Master Elite Consumer Protection Excellence from GAF. He has been serving the Pinellas County area since 1978.  Old Time Roofing has a tradition of quality workmanship, servicing residential and commercial properties.