A secondary water barrier is the layer of material that is placed directly on the roof deck under the primary outer roof covering of shingles, tile, metal, etc. Here are a few reasons why Floridians find that building codes often require them to add this component to their roofing system.
I Don’t Get Ice On My Roof
A secondary water barrier is also referred to sometimes as an Ice & Water Barrier.
First off, don’t trip up on that word “Ice.”
The same properties that prevent ice from backing up under the underlayment that serves as the initial covering on your roof prevent windblown rain from getting to the wood sheathing of your roof as well.
As the hurricane force winds would move over a house, the primary roof cover would be blown off. With the primary cover gone, the materials under them, the secondary water barrier, would then become exposed to the driving winds and rains.
Felt Paper Improvement
The hurricanes that have moved through Florida prove that a different type of underlayment than felt should be considered.
Traditional felt paper underlayment, while it does a good job at stopping leaks, has problems standing where the sheet overlaps the row below and where nails or other fastenings penetrate the felt paper.
When a nail or fastener goes through the felt paper, it creates a hole that is not sealed. Water can get under the nailhead, seeping down the shaft of the nail into the roof below.
After Hurricane Charlie hit in 2004, roofing contractors looked at many roofing failures. Something they consistently saw was that structures that had felt nailed to their roof decks either had the felt blow off or even if it stayed, once exposed could not prevent massive water damage to the homes and businesses it was supposed to protect.
Properties with roofs covered in self-adhering water barriers fared much better.
Under tropical storm or hurricane conditions the seams will lift, causing the felt paper to tear and expose the roof deck when subjected to strong wind conditions.
Why Secondary Water Is Good
The Ice & Water Barriers are made of a self-adhering, self-sealing, rubberized material that not only adheres to the roof but also forms a seal around all nail penetrations. Because Ice & Water Barrier adheres directly to the roof’s surface it will not blow off unless the whole roof deck blows off.
This secondary water barrier has proven so effective because it is a true water barrier. If necessary, a roof deck that has been completely covered by an ice and water barrier can be left exposed for 30 to 120 days without the worry of the effects of UV rays.
This has been a saving grace at times, when major storms have hit the region and primary roofing materials have been in short supply. Had a felt material been used, UV light rays would have started deteriorating the underlayment before the primary roof was installed. It is so effective at preventing leaks due to driving rain that the state of Florida made it a required building material in 2007.
Although the state Florida building codes have relaxed to again allow felt underlayment, most insurance companies give rebates to homeowners who have a quality secondary water barrier installed when replacing their roof.
Insurers have found that homeowners with a self-adhering Ice & Water Barrier for their secondary roof covering have longer lasting roofs. They have also found that Ice & Water Barrier can reduce the risk of damage due to the consequences of a major storm.
Imperial Roofing Contractor knows the roofing codes and has the expertise you need when replacing your roof.
Talk to us today about secondary water barriers – and all your roofing needs.