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How to Install a New Slate Roof

Today we are taking you to meet one of the top slate installers in the country who is also the Executive Vice President of The Durable Slate Company, Mr. John Chan. He will be teaching you how to install a slate roof. Let’s go have a look.

“Hi, I’m John Chan with Durable Slate and we’re here to show you how to do a new slate roof.

We started with this mock roof by installing #30 saturated felt and we used these cat nails to hold it down for heavy wind. So, at the bottom of a roof you can cut drip edge, usually copper, or slate is actually a natural drip edge. So we’re just gonna go ahead and start with wood cant strip.

Now that we’ve got the cant strip installed, we’re going to measure off 10.5 inches because I’m using 12 inch backers.

Now I’m going to install a nail so that I don’t need somebody to hold the chalk line for me.

And right there’s my line. We’ll pull this nail out and we’re going to install the first backer. Because we want backside up, I’m going to punch it from the front side.

Okay, so what we can do right now is I’m going to want one inch overhang here so I’m going to mark it with one inch.

Again, I’m going to punch it from the front side.

Now, notice how I nailed these slates so that they’re flush. They’re not sticking up too high and they’re not pinning the slate down. If you pin the slate down too hard, what’ll happen is that that slate over time with wind will actually cause that nail hole to go right through or break.

So, we’re going to start off with a half piece here, which I’ve already cut. And we’re going to install it right here. I’m just going to go ahead and line this up.

I’m tapping the slate to make sure that it’s good and sound. If I hear a vibration, I know that it’s broken.

Now, you’ll see here why I started with a half row, because this slate goes here and if I’d have started with full row then they would line up. So this one goes right here.

Now, see that seam breaks right here and you don’t want them to line up so that the water doesn’t get in the house. Now, I want to chalk out the rest of the roof. Because these are 20 inch slaves, I’m want only 8.5 inches showing. So, I am going to mark up from here, 8.5 inches. 17, 25.5… So, here’s 8.5, 17, 25.5. Same thing here. Eight and a half. 17. 25 and a half.

And now I can take this chalk line and put it on here. Pull it out and I can chalk this by myself.

I’m going to pull it over to my line. And again, I can chalk it by myself.

With a chalk in line, I can either pull these or nail them all the way in. I’m just going to pull these out.

So right now, I’m going to show you how this roof works. The very bottom row is this 12-inch piece. So you see you’re going to actually have 3.5 inches of triple coverage. You’ve got this slate that you can’t see underneath this slate and this slate. And that’s what keeps the water out because water can’t penetrate this stone.

And continue up the roof.

Alright, so now that we have four rows on, you can see exactly how a slate roof works. When water gets through the slate right here, it spreads out like this. Well when it gets down here, it gets onto this slate, so it gets onto this slate like this and then you have this slate back here, so what you actually have three layers of slate and this what we call the slate headlap.

For here from here to here you’re going to have three layers of slate. As I said, this is millions of years old stone and that’s what’s going to keep your house dry. As we’re going up the roof, what we’re going to do is we’re going to angle our lines so that it goes straight to the top and it looks perfect from the eye because no roof is going to actually be perfect in height from one side to the other. That’s the way you do it at The Durable Slate Company.

Well, like John Chan says, that’s how it’s done. And that about wraps up this segment of HRC TV stay tuned for more educational videos in the historical restoration and construction world. If you would like to see if your company qualifies to be one of our featured businesses, contact us via the information on the screen. See y’all later.

More than a roof. It's a legacy.