Roofing Diagnosis 101: Metal Roof Leaks Around Screws
When it comes to roofs, there are few products that can match the strength, durability, and performance that a metal roof can offer. But like just about anything else, metal roofs are not indestructible and they definitely can spring leaks.
Knowing where and how to identify leaks in a metal roof is the first step towards implementing the repairs that you will need to get your roof back into working order. Here are just a few things to look for if your metal roof is beginning to leak.
Metal roofing screws
More often than not, if you have a leak in your metal roof, a metal roofing screw is the culprit. When installed properly, metal roofing screws will seal out the water by compressing a rubber washer down at the base of the screw head. When the screw is then driven down into the metal roofing panel, the rubber washer will form a gasket of sorts between the roofing panel and the screw head itself.
While this sounds like a simple process, there are definitely things that can go wrong and we will go over a number of those later in this piece. The key is to know that when you have a leak, you should go for the site of the metal roofing screws before checking out anything else.
Here are a few of the ways that a metal roofing screw can lead to a leak in your metal roof.
Under driven screws
This can happen when you don’t have enough torque on the screw as it goes into the metal roof itself. What causes the leaking is that the rubber washer does not properly seat against the metal roofing panel. When this happens, the rubber part of the screw is never compressed and there is no gasket seal that is formed.
This can typically be remedied by tightening down the roofing screws with additional torque. This might not resolve the issue every single time, but it likely will solve the issue the majority of the time. This is one of the easier fixes that you can implement when your metal roof springs a leak, particularly around the metal screws.
This is the other end of the spectrum. In an effort to ensure that the tight seal between the screw head and the metal roofing panel has been met, the screw can be overdriven into the metal roofing panel. This can lead to damage to the roofing panel itself, which presents other problems that may need to be addressed.
The added torque generally breaks the rubber washer and makes it spin out to the side, preventing the sealing necessary that keeps the water from leaking down into the hole. In some cases, you can simply take some of the torque off of the screw; in others, the screw may be stripped and there could be pressure damage to the metal roofing panel itself.
Screw is driven in at the wrong angle
Again, the key to a successful screwing of the metal screw is getting that seal. When you screw down at the wrong angle, there is nothing for the rubber washer to sit flat against. This will result in the seal not taking effect and leaks persisting around the area.
When something like this happens, you can generally unscrew your driven screw and use the proper torque to re-screw it in. You know you have done it properly when the rubber seal sits flush against the metal roofing panel and keeps the water from leaking through.
This is a pretty easy fix as, in most cases, the screw will not have done any damage to either itself or the metal roofing panel. Simply unscrew the current installation and make sure that you screw it in again so that it sits flush with the panel.
Screws that might have missed the wood framing or strut below
When something like this happens, the screw has nothing to seal against and leaks can be hard to find because many times the screw is right there, but without actually touching it you wouldn’t know that it didn’t actually seal or hit anything.
Always double-check to ensure that the screw has seated properly and grabbed onto the strut or wood framing below. You can save yourself a ton of trouble by double-checking your work each time and won’t have to revisit a leak area caused by inefficient screwing.
While it isn’t the most common of causes that there is, you could find yourself having leaks after a proper installation simply because the rubber washer might not be safe or complete. It is also important to check on the screws after each season because hot summers followed by frigid winters are likely to be unkind to those rubber washers.
Over time, and with temperature changes, can degrade those rubber washers and make them lose their seals. When something like this happens, it can be difficult to find a difference between where the screws are leaking and where they are not.
How to prevent leaks created by metal roofing screws
As stated previously, it is essential that you double-check your work before walking away from the roof. Screwing in a screw with too much or too little torque can be a common cause, as can a screw that is placed at an improper angle.
When you double-check your work, you ensure that there are no screws that will slip by you and you should not have to deal with leaks. But should there be leaks in your metal roof, you have a pretty good idea that the metal roofing screws are the culprit. Take a look around, inspect those screws, and make adjustments where you need to.
Leaks in your metal roof don’t have to be a catastrophe. Taking proper care and using common sense can save you a lot of headache and hassle and leave your roof standing up to the test of time and those pesky leaks.