Unusual Slate Roof

[Jim Katen]

I have only passing familiarity with slate roofs, but I've never seen a slate roof system like this. There's plastic interlayment between every course and each slate is held in place by hooks. The overlap between slates is only 1/2" to 1-1/2". Clearly this is some kind of proprietary system, but I'm not familiar with it. Does anyone recognize it? 

[Marc]

I've never seen it but if I had to name it, I'd call it Crap slate.

[Bill Kibbel]

I recently covered this at a couple conferences. This batten track mounted French hook system was developed for a (ceramic) imitation slate roof system.  The tiles are square.  It has now been adapted to real slate (still square). 

The advantage is this system significantly reduces the amount of slate (or tile) needed.  There is NO headlap.  12" tiles with 10" exposure.  I call that negative headlap.  That's why the membrane interlain with each course is needed. 

I know a roofer that installed this on his home.  He gave me samples.  I kinda know the guy that developed this -- then sold it to GAF.  I think they call it TruSlate.

 

[Jim Katen]

Any idea how old this system is? The house I saw it on was built in 1992 and there was no sign of a previous roof covering. 

[Bill Kibbel]

5 hours ago, Jim Katen said:

Any idea how old this system is? The house I saw it on was built in 1992 and there was no sign of a previous roof covering. 

The earliest I've seen the product was around 2005. I think it may have been available for maybe a couple years before. I'm pretty sure it wasn't produced before 2002.

[Jim Katen]

12 hours ago, Bill Kibbel said:

The earliest I've seen the product was around 2005. I think it may have been available for maybe a couple years before. I'm pretty sure it wasn't produced before 2002.

So I'm guessing it hasn't been around long enough for it to show any signs of serious failures yet. . . 

[John Kogel]

Jim, you found one serious failure - the hooks can let go.

There is an opinion out there that the surface of the roof protects the true water barrier which is the underlay. Seems wrong but won't stop them from trying.

The underlay will deteriorate at the gaps. Can't have any gaps.

 

[Rob Amaral]

Silly product...   never seen it around BOS (yet)...  we have plenty of the 'real stuff'.. 

[Jim Katen]

On 8/3/2022 at 5:42 PM, John Kogel said:

Jim, you found one serious failure - the hooks can let go.

There is an opinion out there that the surface of the roof protects the true water barrier which is the underlay. Seems wrong but won't stop them from trying.

The underlay will deteriorate at the gaps. Can't have any gaps.

 

In the picture, I slid the slate up and lifted it out. I was unable to dislodge the hooks when I pulled on them with moderate force. They're not about to let go under the weight of a slate - walking on them, though, that could be a problem. As for the underlay being the real water barrier, that's exactly how shakes work. The plastic under these slates was substantially tougher than the 30# underlayment that we put under shakes. There were no gaps, the slates were butted tight to each other. I can see this system performing well for 30-50 years, depending on the quality of the slates, themselves. 

[epdmcoatings]

On 8/3/2022 at 6:36 AM, Bill Kibbel said:

I recently covered this at a couple conferences. This batten track mounted French hook system was developed for a (ceramic) imitation slate roof system.  The tiles are square.  It has now been adapted to real slate (still square). 

The advantage is this system significantly reduces the amount of slate (or tile) needed.  There is NO headlap.  12" tiles with 10" exposure.  I call that negative headlap.  That's why the membrane interlain with each course is needed. 

I know a roofer that installed this on his home.  He gave me samples.  I kinda know the guy that developed this -- then sold it to GAF.  I think they call it TruSlate.

 

You are always so helpful.