Flat roofs are not ideal - they have a lot of issues with standing water from easily clogged gutters. Ponding water that remains on the roof will eventually find a way in to the substructure. This can easily lead to extensive water damage. Flat roofs require regular maintenance and need to be kept clear of debris as much as possible.
It's starting to rain in the Pacific Northwest and time to perform some simple maintenance on your gutters and downspouts. Downspouts are often connected to gutters with an elbow fitting. Because of the bends in the elbow, these are prone to clogs from pine needles, leaves and other debris. It is important to make sure your gutters and downspouts can actually drain the roof before the rainy season starts. Follow the steps below to make sure your downspouts are ready for the next few months of work.
•Gloves (sharp edges on the downspout sheet metal)
•Screwdriver - typically slotted or a nut driver - usually 1/4 inch or 5/16 inch
•Clog Removal Device - I'm using a stick I found on the ground
•Colorful Language (optional, but satisfying)
Your roof has a tremendous surface area that is excellent at collecting water during a rain storm. Hopefully all that water is going to a gutter and eventually to a downspout. Where does the water go once it leaves the downspout? Ideally, the downspout is connected to a perimeter or stormwater drain so that water is taken away from your foundation. Frequently, water is pooling at the downspout and can make its way to your foundation and lead to a very wet crawlspace or structural damage.
Take a look at the downspouts at your house. Are they connected to a drain system or are they able to spew water on the ground next to your house? If the downspout ends at the ground like the above pictures, you have a potential problem. All that water can erode the dirt around the foundation and lead to moisture penetration at the foundation and in to the crawlspace. An easy fix is either a splash block or a downspout extension (pictures below). They need to go at the end of the downspout and placed so that they direct water away from the house.
Outside view of the shop wall with the leak - it's about halfway down this wall on the inside. You need to look at the two likely causes to determine where the water is coming from.
• Ground sloping towards the wall instead of away.
• Water from gutter/roof system.
The ground is fairly flat here behind the wall. Slight slope from the neighbors yard but overall the grassy area behind the shop wall is fairly dry. No evidence of ground water moving towards the wall.
Always look up at the roof and gutters - even a small drip can lead to problems over time. Right above the location of the leak inside we can find evidence that the gutters have been overflowing and dripping. Note the pine needles and gunk residue from the overflow of this gutter system. The ground under this leak is soggy and muddy. We found the source of the leak.
How to fix (need to be comfortable with getting on a ladder - if you are not, hire someone to do it for you):
1. Look at the gutter system for clogs. Common spot to find it is in the downspout connection or inside the downspout itself.
2. Remove any clogs and debris from the downspouts and gutters. Ensure that water from the roof has a controlled path to the ground.
3. Look at where the water is coming out of the downspouts. Is there a splash block? Is there a connection to a drainage system? Water from the roof needs to be directed away from the foundation and allowed to go downslope away from the structure.
This is an easy problem to fix with just a little effort and time.
Clogged gutters are generally out of sight and out of mind until you start to notice that slow dripping after a rainstorm.
Roofs are a water shedding system and gutters are designed to take all of the runoff and direct it away from the house. For the system to work properly, the gutters need to be capable of collecting a large volume of water and directing it to the downspout.
The gutters in the pictures above have a bit of a problem. They are filled with tree leaves, pine needles and are a prime breeding ground for moss. Water draining from the roof is supposed to enter the gutters on the eaves and have a controlled path to the ground through the downspout.
With these gutters, water can enter but it can't flow toward the downspout. Water will pool and eventually overflow the edges both next to the roof and over the far edge. This moisture will wick up into the roof sheathing and under the edge shingles causing damage over time.
As you can see in the pictures below, prolonged pooling water has damaged the eaves of the roof and are causing rotting on the sheathing and fascia. This weakens the connection of the gutters and they have started to pull away from the house. Water from the roof will not get all the way in to the gutter and will instead run drip over the fascia and wick into the eaves. If this goes on long enough, damage will start to occur on the walls of the house.
The solution to this problem? These gutters need to be thoroughly cleaned and re-attached to the house. That will help mitigate the immediate problem but to help prevent future problems, the homeowner needs to start a regular, yearly cycle of gutter cleaning and maintenance.
Check out the video below from This Old House on repairing an aluminum gutter system.
Brian Jovag, owner of Jovag Home Inspection.