What You Need To Know About Brown Streaks On The Vinyl Siding Under Your Roof Line

17 November 2015
 Categories: , Articles


If there are brown streaks near the roof line on your home's vinyl siding, the cause of the problem could be in your roofing and/or ventilation system. Brown streaks on your siding are red flags that could mean you have extensive water damage inside the cavities of the exterior walls of your home. Here's what you need to know. 

Identifying the brown streaks

The brown streaks are caused by water that has infiltrated into your wall cavities from a leaky roof or a poor attic ventilation system. The discoloration is caused by tannin in the wood, which the water collects as it leaks through.

Tannin is the same staining substance that is found in tea, coffee, and wine. These brown streaks can be removed by scrubbing them with a hot, soapy water mixed with a few drops of bleach. 

Other places that may have water damage 

While it can be troubling to see your house weeping with brown stains, it is crucial that you check through the rest of your home to look for other signs of water damage. Obviously, if there are brown streaks forming on your exterior walls, there will likely be wood rot and/or mold growing inside those walls and nearby ceilings.

The insulation inside these walls will also be damaged, which will make the insulation ineffective in keeping your home at a comfortable temperature year-round. There's also a concern of the electrical wiring in those walls and nearby ceilings being wet, which can pose a fire hazard. Therefore, it's important to locate water-damaged materials and replace them when found. 

How to safely find water damage inside walls 

Of course, you don't want to rip out walls to see if the materials inside are water damaged, just in case there is no damage. Fortunately, you can hire a home inspector or a leak detection service to look for water damage by using infrared thermal imaging. This is a device that uses an infrared camera to scan the walls for signs of temperature differences. This works for detecting water damage because water absorbs heat, which the thermal imaging picks up. 

Being able to see where the water damage is inside the walls can help you figure out where the water and moisture is coming from, and it can also help you in knowing exactly what materials need to be replaced and repaired through water damage restoration services, which is necessary to prevent the growth of mold inside the walls. 

Common causes of water leaks and moisture

Water can leak through roofing that is damaged. Here are the most common causes of roof leaks:

  • broken shingles
  • cracked flashing 
  • cracked chimney 
  • cracked vent boots 
  • unsealed valleys 
  • ice dam formations 
  • clogged gutters 

Excessive moisture in the attic can also cause enough condensation to form to cause puddling of water, which can be enough to leak through the building materials and cause brown stains on your siding. Here are the most common causes of excessive moisture in attics: 

  • poor attic ventilation 
  • not enough attic insulation 
  • bathroom and kitchen vents venting to the attic 

Repairing the damage 

Contact a roofing contractor like Welty Custom Exteriors, Inc to conduct an inspection of your roofing and attic ventilation system. It's a good idea to already have the report from the results of an infrared thermal imaging scan so you can show the roofing contractor where the water damage is concentrated. This can help the roofing contractor determine the location and extent of the roof damage and/or other causes of the water damage. 

It's also a good idea to have your roofing contractor consult with your water damage restoration service to determine the appropriate steps and timeline for the repairs that may be necessary to the roofing and the structure of your home.