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Out-dated T-Lock Shingles

by Mike Powell

in T Lock Shingles

T-Lock Shingles – Does Your Roof Look like a Q-bert Game?

The picture below shows a section of roof covered in what’s called T-lock shingles. If you have these roof shingles on your roof … dial my phone number right now, then finish reading this while it rings …

T-Lock Shingles

Many roofing companies are spreading the “doom and gloom” scenario about these T-lock shingles, and, while they may be exaggerating (a bit), they’re right to some extent. However, they are also somewhat misguided and perhaps a bit uninformed.

What are these other roofing companies saying about T-lock shingles?

They say things like you need to replace your roof because they don’t make T-lock shingles anymore.

“Really? That may be true, but why does this mean I need to replace my roof? They don’t make me any more either, so should I be replaced, too?”

(I laughed one time when an older woman told this to an overly ambitious salesman I was helping, who knew very little about roofs.)

What you should be concerned about is

“WHY aren’t these T-Lock shingles being made any more, and HOW can this affect my home.”

The reason T-lock shingles aren’t being made any more is because they’re old technology. T-lock’s don’t work nearly as well as today’s modern architectural shingles rated for 130 MPH wind resistance.

At one time, T-lock shingles were believed to work better in high-wind areas than their “3 tab” style alternative … because the “wings” on each shingle were interlaced and nailed down behind the next shingle reducing “blow off.” However, they are rated for 90-110 MPH winds depending on a few factors, and the Front Range FREQUENTLY sees 100+ MPH winds causing rips in the corners of these T-lock shingles.

Rain, dew, snow melt, frost, and other forms of moisture can get down into these cracks wreaking havoc on your roofing system in two ways;

1) The damage water does to asphalt materials in general. Of course, water itself doesn’t hurt asphalt, but algae and fungus do. The continuous presence of water permits algae and fungus to grow on asphalt materials.

2) The freeze-thaw cycle. In the cold months, water gets into the cracks, and then freezes at night. Water expands as it freezes. So the more this occurs, the bigger the cracks or splits become … and the cycle continues on and on.

T-lock shingles also don’t work as well as today’s architectural shingles to protect your home against hail.

All over the region you can see older roofs with multiple layers of asphalt shingles (more on this later). However, recent building codes no longer allow “roof-overs” for the same reason that T-lock shingles are less effective versus hail—they don’t lay flat.

T-lock shingles in their fundamentals are woven, partially over and partially under, their neighboring shingles. That means air pockets, gaps, wrinkles, and otherwise not having the benefit of a sturdy plywood deck providing needed support.

Obviously, this doesn’t apply to the entire roof, but it does apply to portions of every T-lock shingle—a large enough portion of your roof to cause concern.

These portions of every T-lock shingle don’t allow the hail to bounce off without causing harm. It’s like bubble wrap (only not an exaggerated simile). If the hail hits the non-bubble part, it bounces off. No harm done. If hail hits a bubble… pop, crack, etc. See above for what happens when your T-lock shingles get cracks.

We can now see the obvious reasons why these T-lock shingles are not great for your roof system in the Front Range region. However, as these shingles were discontinued around 2005, if you still have these shingles on your house then you may think you have averted the possibilities stated above and think you’re in the clear.

Well, insurance companies know the possibilities I just told you about, and they also know the shingles were discontinued. So some insurance companies have begun to make adjustments to their policies. If you try to take out a new policy, some companies won’t insure T-locks. (Try selling an un-insurable house in today’s market.)

Some companies have even sent out letters to houses with T-lock shingles stating their deductibles are now being raised. Other home owners have received letters that their roofs will be depreciated. (This means they can’t get full value for any future claims.)

In short, insurance companies are beginning to push the financial responsibility onto home owners because they know that it’s only a matter of (not much) time.

Did you get through all this info about T-lock shingles before I answered the phone? Have you called me yet? Why not?! Call now before you get a letter in the mail stating your coverage is being affected by your T-lock shingles.

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{ 2 comments… read them below or add one }

Kevin Odenweller September 29, 2012 at 5:39 pm

Hello Adam,
I have T-locks shingles and the hailstorm this summer is causing their replacement. What is a comparable replacement shingle? I have see other homes in the community replacing the t-locks with what looks like low grade 3-tab that the winds removed a few years later. Yet other neighbors have been able to replace with what appear to be Owens Oakridge® Shingles or GAF Timberline® mid grade shingles. I like to hear what you know about shingle replacements and comparable shingles to T-locks.


Adam September 29, 2012 at 6:03 pm

Generally insurances pay for a 30 year shingle as a replacement for T-locks. So 3-tabs would be a down grade, and Oakridge or Timberline would be equivalents as far as life expectancy. Any roofer worth his salt would refuse to install 3-tabs any more. They’re just sub-standard for the weather conditions here. Plus, even if 3-tab was the original roof, insurance pays enough to give a free upgrade when it comes to shingles. A lifetime, or 50 year, dimensional shingle would be the recommended upgrade from T-locks. So the question now would be… why aren’t any of your neighbors getting an upgrade from what they had?


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