Problems with stapled shingles

While it used to be common practice to use staples to attach asphalt shingles to a roof, this has been a prohibited method of attachment in Minnesota since 2003.  Today, staples are considered an inferior method of attaching shingles to a roof, but it’s easy to understand why roofers like staples.

• Staple guns are smaller and better balanced.  Coil nail guns are literally fed with a coil of nails, and the holder for the nails makes the gun much bulkier.
• Staples are far less prone to jamming up in a gun than nails.
• Staples cost less money.
• Staples are much more compact; a roofer can hold a bunch of sticks of staples in their pocket and reload their gun very quickly.  Nail coils take up a lot more space, they take more time to reload, and they need to be treated carefully; if a coil of nails gets dropped or stepped on, it deforms the coil and makes it much more prone to jamming in the gun.

Staples are used because they make the roofer’s job easier; they don’t equate to a better installation.

The problem with stapled shingles is that they have a much greater chance of coming loose or blowing off the roof because staples are so easy to install improperly.  When a roofer holds a staple gun and fastens a shingle, the staples will have a tendency to be driven at an improper angle.

Staples are often improperly installed because it’s somewhat awkward to hold a staple gun completely perpendicular to the shingle.  For someone who is right handed, it’s much easier to shoot the staples on the left side of their body at an angle similar to a forward slash, and the staples on the right side at an angle similar to a backward slash.  The two super-crude diagrams below should help to illustrate what I’m talking about.

When staples are installed properly, they work fine, but they’re just too easy to install wrong.  This issue doesn’t happen with nails, because they have a round head; as long as a nail is driven in to a shingle straight, it doesn’t matter which way the nail gun is turned.  To know if a roof has been installed with staples, you can sometimes see the outline of the staples pushing through the shingle above.

   

Also notice, these staples aren’t perpendicular to the shingle.  This is the installation problem that typically happens with staples.

If you have a roof that’s been installed with staples, is it a defective installation?  If it was installed after 2003, technically yes, because staples aren’t allowed any more.  If every staple was perfectly installed, the installation would work just as well as perfectly installed nails, but I’ve found improperly installed staples at every stapled roof I’ve inspected.   If you have a roof with stapled shingles, you don’t need to replace the shingles as a rule of thumb, but you’re taking on some risk.  If shingles start blowing off on a regular basis, you’ll probably want to have the roof covering replaced.  This will be less costly and less of a hassle in the long run than having to deal with constant roof repairs.

When I inspect a house with shingles that have been improperly installed, I tell the same thing to my buyers; the shingles don’t need to be replaced, but they might cause some headaches.  If shingles have already started coming loose and obvious repairs have been made, I typically recommend replacement of the roof covering.

P.S. – Special thanks to roof guru and fellow home inspector Mike Moser for always knowing the answer to any technical roofing question right off the top of his head.

Reuben Saltzman, Structure Tech Home Inspections - Email- Minnesota Home Inspections

        

Who Inspected Your Roof?

Last week I mentioned that municipal inspectors will sometimes miss important details on permit inspections, partially because they just don't have the time to go over every little detail on a home the way that a private inspector does.  That reminded me of another aspect of municipal inspections in the Twin Cities that most people don't know about:

Municipal inspectors typically don't walk on roofs to inspect them.

That's right.  When municipal inspectors in the Twin Cities come out to inspect roofs, they will rarely set foot on the roof, or even lean a ladder up against the roof.  The rules vary between cities - some prohibit their inspectors from walking roofs, while others actually provide ladders for their inspectors.

So why don't municipal inspectors walk on roofs?  Because they don't have to.  It's documented in the Minnesota Administrative Rules for Inspections (1300.0210, Subp. 4.):

"The person requesting an inspection required by the code shall provide access to and means for inspection of the work."


This means that if you expect your municipal inspector to walk on your roof, or even use a ladder to inspect it, you better have a ladder leaning up against your roof when they show up.  They probably won't be bringing their own ladder.  If you DO have a ladder... they still might not.

Roofing contractors all tell me the same thing; municipal roof inspections are anything but thorough.  One roofer told me that city inspectors barely get out of their vehicles.  I have a high degree of respect for municipal inspectors and I had a hard time believing my roofer friends.  To find out for myself, I sent out emails to twenty of the largest municipalities in Minnesota, asking if their building inspectors will walk roofs.  I wrote:

"If a municipal inspector is coming out to inspect a permit for a residential roof replacement, will they walk on the roof to inspect it if a ladder is provided?  The roof has a pitch of 4:12, and is free of snow, ice, water, debris, etc."

FYI - A 4:12 roof is a very low-sloped roof (see photo above).

Here are the responses I received:

• No response - 4
• No. Inspectors are not allow to walk on sloped roofs, period - 4
• Maybe? Vague answers to my direct question - 4
• Yes. As long as all of the requirements listed above are met - 7
• Yes, we rock. Department policy requires inspectors to walk on roofs with a slope of 6:12 or less, and the inspector's vehicles are equipped with ladders for doing so - 1 (Saint Louis Park).

Go Saint Louis Park.  Their municipal inspections department continues to impress me.
Here are two more tips I picked up from the email responses that I received:

• Some municipalities allow / require digital photos of the roof underlayment in lieu of an initial inspection.  The City of Blaine (among others) has a document detailing how to send in digital photos to the building inspections department.  Click here to see it - scroll to the bottom of the document.
• None of the municipalities will approve permits when the roofs are covered with snow.  Homeowners are supposed to call for inspections in the spring, after the snow has melted.  Municipalities end up with "hundreds and hundreds and hundreds" of roofing permits that never get closed out.

If you have your roof replaced, make sure someone leaves a ladder for the inspector.  At least this way you'll have a chance of someone getting on your roof to inspect it.


Reuben Saltzman, Structure Tech Home Inspections - Email - Twin Cities Home Inspector
    

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"...But The City Approved It!"