Roofing Nails, Plumbing Lines and Building Codes – Oh My!
One of the perils of the roofing industry is when other trades, specifically plumbers, HVAC and remodeling contractors, run their water, freon or drain lines too close to the decking of the roof. By code, roofing nails have to penetrate the decking, and the industry standard for roofing nails is 1.25” nails. When these two events collide, disaster strikes. Who is at fault?
I’m sure many a homeowner has walked into their attic and been shocked by the thousands of nails that they can see coming from through from the deck. If you aren’t careful, it’s a good way to gouge your head. In Texas, an average roof is about 33 squares (a square in roof lingo is 100 square feet, so that’s 3300 SF). The average bundle of shingle has about 27 shingles – there are 3 bundles in a square – so in a 33 square roof, it is approximately 2,673 shingles being installed – let’s say 2,500 for the sake of easy math. Most manufacturers require 4 nails per shingle, some installers use 6 nails to increase the wind rating. That means the average Texas roof has 10,000 to 15,000 nails that you can see from the underside!!!!
If a waterline or pipe is installed too closely to the roof deck and is not properly protected by a steel plate, the odds of it being hit by a roofing nail are pretty high. We find the most likely place for this to happen is in the eave – where the line was ran up the outside wall of the home and hits the eave/soffit. Even if an attic inspection is performed by the roofer, seeing every nook and cranny is difficult, if not impossible, depending on the roof, the structure of the home, and the pitch. Some areas can even be completely inaccessible or blocked off.
Often when a roofer hits a line, they know it right away, and they can scramble to minimize the damages. We tell our crews to turn the water off at the street as soon as possible. Making the repair can be fairly simple if you know what you are doing, as long as you know it needs to be done.
Unfortunately, if the water doesn’t leak onto the roof deck, there’s no way to know the line was hit. And if no one is home, this can turn into a disaster. Another thing that happens is the line is hit, and instead of bursting, the nail actually originally seals and there is no leak. But as the nail sits in the water of the line, over time, it will corrode and eventually it will leak – this means you can have a leak years after the roof installation.Who is to blame? The roofing contractor blames the other trade for an improper installation, which is true. But the code is unfortunately not crystal clear. Here is one building code that we refer to in Texas:
The 2024 International Plumbing Code (IPC) General Regulations states in Chapter 3, 305.6 that “In concealed locations where piping, other than cast iron or galvanized steel, is installed through holes or notches in studs, joists, rafters or similar members less than 1.25” (32 mm) from the nearest edge of the member, the pipe shall be protected by steel shield plates. Such plates shall cover the area of the pipe where the member is notched or bored, and shall extend not less than 2” (51 mm) above sole plates and below top plates.” Unfortunately, this code is talking about rafters and not roof decking, and in ways seems more applicable to drywall fasteners, but the spirit and intention of the code is to not place lines somewhere where they will be punctured without being protected. It makes sense.
Chapter 9 of the ICC (International Code Compliance): Roof Assemblies – R905.2.5 states “Fasteners for asphalt shingles shall be galvanized steel, stainless steel, aluminum or copper roofing nails, minimum 12-gage shank with a minimum 3/8” diameter head, complying with ASTM F1667, of a length to penetrate through the roofing materials and not less than ¾” (19.1 mm) into the roof sheathing. Where the roof sheathing is less than ¾” (19.1 mm) thick, the fasteners shall penetrate through the sheathing.” In today’s world, most decking is 7/16” thick. The nail is going through 2 layers of shingles usually (often where at least one shingle is two ply). If the shingles are 3/8” and the decking is 7/16”, the nail needs to be at least 13/16 of an inch. A 1” nail would penetrate the deck, yet the industry standard is 1.25”.
In order to protect themselves, most roofing contractors have written into their contract language that they won’t cover damage to lines within a certain distance of the roof deck – anywhere from 1.25” to 3” is pretty standard. Yet most customers don’t read that much detail in their contract, and when the damage is done, they expect someone to pay for the damages. It’s an unfortunate event all around.
In our municipality of New Braunfels, Texas, we have found the city inspectors hesitant to take a strong stance on this issue. They will verbally say (if there are no witnesses) that the plumbing lines being that close to the roof deck go against the spirit of the code, but it is not enforced or checked during plumbing and HVAC inspections. It’s a little like nailing jello to the wall – I don’t think there’s a code about that either!
Yet many a roofer finds themselves on FaceBook industry pages looking for insight, in court with disgruntled customers, or filing claims on their liability insurance policy they carry. Homeowners too can find themselves in a bigger mess than they anticipated. Of course, if the damages are extensive, homeowner’s insurance would likely assist with the damages, but that’s not the ideal outcome for anyone.
This is why in October of 2024, after much extensive research, we decided at Roofer Chicks to break away from the industry accepted standard of using 1.25” nails and switched to 1” nails. After all, just because that’s the way we have always done things doesn’t mean that it’s the best way. Of course, this doesn’t totally eliminate the issue of hitting improperly placed lines, but it certainly is a step in the right direction. At Roofer Chicks, we think through each part of the process, even down to ¼” on the nail length!
