Search function worked well today, but I didn’t find a lot of advice on installation.
Roof is 18/12 and I have crates of new slate, quarried around 1910. The house where the rest was installed is in great shape, so it must have been good stuff. It’s all only 10″ tall. Not particularly worried about the weight, sitting on full dimension 2×6 oak rafters, 10′ span, rest of my building is similar. No valley or protrusions.
This is a separate roof section where I was thinking of using the slate. Remainder will be copper standing seam. 2200lbs awaiting me.
Question of overlap. 4″? Cutting? Windy location, 30′ up, I was thinking stainless screws. Oak is green so fasteners work fine. Copper ridge cap OK? Glued on? Building unheated, no ceiling. Anything else I missed? Other than somebody to haul them up there for me….
PAHS Designer/Builder- Bury it!
Replies
I've used copper nails.
There is a slate shingle cutter available. But they are hard to find. Not all roofing suppliers carry them. They are a must have for slate. No scoring and cutting.
Ridge cap - copper, nailed and overlapping next course of slate, sheated with slate.
Wear a roofers harness. Slate is very slippery and some shingles will break/ come loose when you walk on them. Footing is uncertain.
They have lifts which opperate on ladders for carring the materials up. Fork lifts work well too however 30" high is high. If you can use a winch (or wench) will work but where do you install it?
F
Right about the slippery! I don't know of anything that can take you down any faster.
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Thank you.
Fall protection I have. Can't imagine anybody managing to walk on such a steep pitch. Below is a much shallower pitch around 4/12, not yet covered with copper, to base the ladder on. High enough to make me queasy. Figured I'd do better to roof the highest, steepest parts first. Those rafters rest on 28" tall walls, so not a great distance down to the next roof.
I can use a loader to get the slate to within 10' elevation, inside the building, next to top floor. Through what'll look like a hay loft door. Unfortunately, no wenches available. Am planning to winch the cupola up there. Didn't figure it was worth setting up for 2-3 sqs of slate.PAHS Designer/Builder- Bury it!
I haven't done all that much slate, so take this with half a grain...
First - especially with used slates, get in the habit of tinking each one to test it. You hold it by a corner when you grab it and use the hammer ( a slater's hammer is invaluable for doing this work for a number of reasons) to "tink" the slate. If it is good and sound, it will ring true to the ear. If it has a hidden crack that will split off or allow leaking later, it will have a dull "thud" sound.
Size - The ones I laid were about 16 - 17" tall and the nail holes were at 10" up from baottom. We installed with the nail just touching the top of the preevious course for alignment. I don't know about yopur shorter sizing for sure, but you can figure out what is optimal by laying them out for several courses on a firm flat surface and playing with various exposures. What you want is for the exposure to be such that the top edge of the slate is on the sheathing, and the butt is aligned with the angle created by the lapping of the lower courses. Too close and the butts will stand proud to catch wind and let water blow up in. Too shy and the nails can create a belly at the mudpoint and possible want to break the slates.
Fastening - definitely use ring shanked copper roofing nails. They will hold, not decay, and the smooth maleable haed will not create stresses in the slate. The head is thin enough to fit the nail pocket in th e face of the slate so it doesn't leave a bump to stress the next slate laying on top of it.
Underlayment - a minimum of two plies of 30# felt, evn on this steep pitch
Ridge - The copper sounds decorative and easier by far than doing a slate ridge and it will go well with the rest of the job being copper.
Cutting - Here is where the slater's hammer will serve you well. It'll take some time to describe this technique, so I'll come back in with another post.
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For cutting, this is hoiw I learned to do it....I'll describe this for right handed, since that is what I am-
There was a cutting bar that anyone can make out of 1/4" x 1" bar stock. It is just a long "T" with an eight inch tail and a 24" top. Grind a point on the tail so you can just swing the top in hand and stick the tail into the roof ( or in the case of a really stepp one, into the staging plank where yuou want your cutting space) so the bar is in a horizontal position, with a bit of space around it. Also grind the top edge of the bar t top so the whole up-facing edge is beveled at about 30°
now - a minute for the beauty of a slater's hammer. It will have a small head, about 5/8" so you can use it to tap the copper nail into the nail indente just the right amount with out hitting the slate itself and cracking it. It has a point at the opposite end where carpenters normall find their claw. This point is for poking holes in the slate. You hold the slate with backside facing up, across the cutting bar so the spot you want a nial hole is near the support bar. Then a sharp whack with the point will flake out a hole in the slate without breking it. The missing flake leaves a dimple recess in the face that hides the head of the nail.
Some slate hammers have a claaw in the side of the the hammer head, some are smooth.
The handle of the hammer is long and metal, kind of like the Estwings. It will have a bevel in it like the bevel on the top of the cutting bar. You use this edge for cleaning up the cutt edge of the slate when you have to cut one for an edge or a valley.
To cut for a valley, look at the attachments. Easier to show than to describe verbally, but you have to poke yourself a line of holes in the slate, and then knock off the waste siode piece. So this first cutt to leave about an inch of jagged edge, and then trim by flaking with the hammer handle edge by about a quarter inch at a time to get true to finish cutt on the slate. You do this with the back side facing up to you so the chpped edge faceds up on the roof.
This takes some practice, and a feel for the slate. There are different thicknesses and qualities of slate too. A thicker slate means that you will need to start further from the finish cut line and do more flaking back. You will waste your first four or five slates and you will find several more bad ones that break wrong, so don't lose patience with yourself..
Good luck.
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Fantastic! Thank you. The drawing made the cutter clear. I'd been thinking to use a tub saw. Obviously not on the roof.
These are all new pieces, just old. I'll try the sound test anyhow. Cleaned out a barn for a lady who stiffed me on the last-minute job while she saved herself $5K for getting it cleaned out before closing, 2 days later. At least I did get the slate, which will save me nearly $1K worth of copper, if I can get it up correctly.
I did find an old conversation between you and greencu on how to hang slate in valleys, strap and wire. Design for this roof took into account my lack of experience, no valleys. You surprised me with the 2 felt layers. Most of the attics I've been in had nothing between the slate and the 1xs.
The copper nails I can find have next to no barb on them, why I was thinking of screws. I toenail the copper cleats to compensate. Wind lift was what worried me most. That, and guaging when to stop hitting the nail. Guess I need to break a few to learn.
Thank you for taking the time. PAHS Designer/Builder- Bury it!
"It's all only 10" tall."
Are you saying the slate is only 10" tall? That is something I've never seen before. Are you sure you don't have starter slates, or ridge cap or something? The reason I ask is the proper way to figure your exposure it to subtract 3" from the length and divide by two. Since your installing on an 18/12, I would feel comfortable going down to 2" double lap, but that still leaves an exposure of just 4". If that's the look you're going for then great.
"Cutting?"
Here is a great link for slate tools.
http://www.stortz.com/slatecutters.html#traditional
Cutter model# 95-A is similar to what I'm using. Some slate is too brittle to use a slater's hammer on. If you don't have too much to do, I would just cut with a diamond blade in a grinder. No protrusions, so you will need 1.25 cuts per course, which can be done on the ground and with little chance of shattering the slate.
I don't think stainless screws are necessary. I would use cu nails, at least 1-3/4" for 1/4" slate. 2" would not hurt.
Will you use roof jacks and planks as staging? I usually use 3 adj. jacks for a 16' plank. When you install your jacks, set them directly on the sheathing, not over the slate. When shingling around them, I usually use a diamond pattern that makes it easy to remove the jacks by pulling the nails. Often you can nail all but your last shingle. For that one use a slate hook.
You can use copper or slate at the ridge, I would prefer copper. I have some old instruction sheets around here somewhere. I will try to find them and scan them for you.
If you have any questions feel free to post or email. I will try to help out as much as possible.
Jon Blakemore
Are you saying the slate is only 10" tall? That is something I've never seen before. Are you sure you don't have starter slates, or ridge cap or something?
Yes, only 10" tall. I assume they're starters. Why so many, I have no idea. Just what was in crates in the barn. I figured with that pitch, I couldn't go very far wrong. I was looking at the overlap very much as Piffin's drawing. The closest point anybody will ever get to see it from, is 75' away. Was just going to use the slate and be happy with however the exposure came out. Need to know first, to be able to plan how far the slate will go. Little chance of my heading down to the quarry if I run short. Copper, I've got.
Tub saw has a 14" diamond blade. Gotta try the tool though.
Roof jacks and planking scare the crap out of me. I figured on a ladder secured to the (not yet coppered) lower roof. This is a small area, a little over 1 sq. on each side of the bldg. Slow is OK. Everything else has been.
Instruction sheets would be fantastic. And thanks for the link. Part of all this is curiosity to do it once. With a quarry an hr away, and 3/16" pricing that's $325-450/sq, you never know when you might want to do it again. Hmmm, those 10x8's are worth $250/sq., just about the same as copper. And they do price them by the sq. Somebody must be buying them. Is a sq a sq of roof, or a sq of slate laid flat without overlap? Was down there just once, hauling 2 tons of slate for a new house sidewalk. Very friendly folks. Brochure says"one of the hardest slates in the world".
Much appreciate your offers. PAHS Designer/Builder- Bury it!
"Tub saw has a 14" diamond blade. Gotta try the tool though."
I forgot that you mentioned that you had that saw. I would use that exclusively. I can't imagine why it would not work.
I think your ladder idea is good as well. Just use a piece of ply when you have to lay on top to distribute the weight.
Jon Blakemore
Tub saw would work for just a few, but it could be more time consuming if he had to run up and downthe ladder all the time to use it as opposed to cutting close to point of use, generally. I see he plans to work off the ladder and make things slow anyway though.
But He shopuld still absolutely always tunk each slate first when picking it up to use to be sure that it is sound and rings with a tink instead of a tud. From that high up, a bad slate breaking off and falling on something will do damage, and be hard to repair later.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Sorry about the confusion, the tool I was referring to with Jon, that I have to try, is your cutter. "Tink" or "tud", LOL, I think I got it. Rainy today so I spent time maintaining DW's van instead of tapping slate.
Don't yet have all the rafters up either. We're still sawing. I will be able to reach both extremes (L and R) of roof from one central ladder position. I'm slow, but don't intentionally make it any worse. For the copper portions, I'll be "walking" on 18/12 and 4/12. If the slate turns out odious, I'll bail, in favor of copper. Seemed like a good opportunity to try something new. Assuming they aren't all tuds. <G>
This odd building is unfinished except for the 2 concrete floors below the post&beam (2 drive in levels). I'm really looking forward to a roof so I can comfortably floor the 2nd and 3rd floors (no sub-flooring). This is really not that far off from a traditional barn here, including construction methods. Pictures soon.
By the way, green oak 2x6x17' are really heavy.PAHS Designer/Builder- Bury it!
It sounds interesting. Go with the slate. I look forward to the pictures
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Tub saw has a 14" diamond blade. Gotta try the tool though.
A diamond blade will cut the slate beautifully. The problem is all the other edges will be somewhat irregular. The tub saw cuts will stick out like the preverbial sore thumb. When using a slate guillotine, you cut from the back. This produces a clean edge on the back and the relieved edge on the front as the cutoff flakes off a little.
With that steep of a roof, I would do the slate first and then do the copper and bottom several courses of slate. One dropped slate will ruin a nice new copper roof, plus lots of grit will be landing on it.
Leave at least three courses off, and high nail the fourth. When the rest of the slate is finished, install the starter row and the next two courses normally. Slide each slate on the fourth row in and nail thru the gap (trot) in the fourth course to hold the 3rd course slates in place. The nail head will be visible. Take a 2" wide strip of copper and cut numerous 1/4" slices into each side at at 45 degree angle. This will produce a bunch of sharp prongs on each side of the copper piece. Push the copper piece under two fourth row slates where it covers the nail in the trot with the prongs pointing down. They'll dig into the slate and hold the copper strip ( I've heard it called a "baby" ) in place. Have fun.
The tub saw cuts will stick out like the preverbial sore thumb.
Completely understand.
But I'm afraid you lost me on the rest. These roofs do not connect. What I'm attempting are 2 narrow sides of a short ridge to cover with slate. The copper will be below, on a separate roof. No slate/copper connection, other than the ridge cap.
I too was thinking that the slate came first, partially so I had a good place for the ladder. Also dropping slate, tools, whatever, had occurred to me. When the slate was totally finished, the copper would be started on the other, separate, roof planes. I'll also be doing the 18/12 copper before the 4/12 copper, which is directly below it. The 4/12 plane is continuous, below the 18/12. Hope I haven't totally muddied the water. From the ridge: 18/12, short wall, 4/12. Cupola interrupts the 18/12 plane. If you already understood this, my apologies.
Do I really want to leave off the lower courses of slate for the end? I was planning to start with a copper strip, followed by courses of slate. I haven't seen a copper strip placed between courses of slate. Maybe I missed the baby? PAHS Designer/Builder- Bury it!
not between the courses, more like a spline betwix the slates on the uppermost course to cover the nails ya put in in the space between the adjoining slates..because you highnailed that course..some call it a feather too..
I did alot of slate in Bethlehem Pa. all around the steel mill..witches hats, steeples..you name it. I hate slating.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
I hate slating.
Trade you a wood-fired boiler that'll take 4' logs? Your place could probably use all that heat. <G> Hey, and you can meet my buddy John the luthier (who has the copper seamers).PAHS Designer/Builder- Bury it!
I missunderstood. I thought the 4/12 and the 18/12 intersected.
The tub saw cuts won't match the other two exposed sides on the cut slate. Cut one and you'll see what I mean.
If you're working by yourself, you might consider a boom lift if there's access. It's amazing how much one man can do in a day with a boom.
I think u mean "bib" but close enough nail it
Maybe that's it and the piece that some roofers nail down under the slate and bend back up under the bottom to hold the slate in place is a "baby". I've also heard "feather".
i did some more checking and the biltmore actually does have the rooftop tours year round- they're just much more likely to be cancelled due to poor weather in the colder months. since much of the tour involves balconies and parapets they are particularly cautious about any ice. one other thing i did notice on their website was that if you pay for a general admission and then sign up for one of the specialty tours the following day you don't need to pay the main fee again, so you basically get a twofer if you want to spend that much time there. (which is not a bad idea because there's a lot to see with the grounds, the winery, etc)
m
Great. Thanks. Keep you posted.PAHS Designer/Builder- Bury it!
Jon posted the link while I was hunting for it. You can get a slate cutter from Stortz for $50-$60. That's pretty small slate. It may be ridge pieces or starters as suggested. 4" reveal is the max you should show. I've done steep roofs like this with ridge hooks/chicken ladders and ladder jacks with with a walk board between them. I think Stortz has got ridge hooks also. Have fun.
Good source of info is jenkins slate company,I recall the web site is
http://www.jenkinsslate.com The "Slate Roof Bible" is a must read also.
Joe
Renaissance Restorations
Antique & Victorian Home Restoration Services
http://www.renaissancerestorations.com
Last roof I did a while back, I put down ice/water shield for the 1st few courses. Cutting the slates, I used an air powered grinder with a cutting wheel attatchment. Nice to see someone still using slate, as I worked in a neighborhood a while back where 4 houses were having all the slate removed and tossed into dumpsters, and (ugh) conventional asphalt shingling put up. I did manage to salvage some of the slate, (after dark...)
Joe
Renaissance Restorations
Antique & Victorian Home Restoration Services
http://www.renaissancerestorations.com
Thanks for the JenkinsSlate link. Their primer was just what I needed. I don't understand any attraction for asphalt, other than low initial cost. Far as I can tell, copper's cheaper- considering lifespan costs. Slate is intriguing.
As my signature line suggests, I only consider dirt roofs over living spaces, but that's clearly a (tiny) minority position. Slate and copper over a lumber drying/storage facility? Sure, why not? Again, lifespan costs.PAHS Designer/Builder- Bury it!
Hey Va Tom -
Joe Jenkins just put out a new edition to his book but, with all due respect to him, I found that this is a better book:
http://www.neslate.com/SlateBook.html
It has more "how to" type info whereas Joe's first book was more historical. Both are good and Joe's latest is probably a lot better but the link I provided has what you are looking for.
Your 4" exposure will give you a 2" headlap which is, maybe OK given your slope, but a 3" headlap is "recommended" and to do that you need a 3-1/2" exposure.
I have ridge hooks & ladder hooks and slate cutters if you are interested and hey, I'm just in Silver Spring, MD.
Eric S.
I have ridge hooks & ladder hooks and slate cutters if you are interested and hey, I'm just in Silver Spring, MD.
Thanks for the offer. Let me see what I can scrounge up without the drive. It ain't the distance, but that traffic I sure try to avoid. Unless, of course, you want to come down and demonstrate? <G>PAHS Designer/Builder- Bury it!
Eric -
Are you interested in selling any of the slate cutters? Which ones do you have? I come to DC often if mailing isn't feasible.
F.
I have the GT Handy cutter from Jenkins. Definitely works - especially in the hands of an amateur like me. Obviously would love to sell my package, i.e. ridge hooks, ladder hooks, slate ripper, cutter, hammer.
Eric S.
I am looking for the Pro cutter. What are you asking for the package?
F.
just the other day the loml and i took a rooftop tour of the biltmore estate (highly recommended if anybody is ever out this way!) and the <acres of> slate shingles all had two pairs of holes drilled in them and they were wired to the iron space sheathing from underneath. almost no work was done from the outside. maybe something like that could be made to work for your job?
m
slate shingles all had two pairs of holes drilled in them and they were wired to the iron space sheathing from underneath.
Iron space sheathing? Did you see it?
Biltmore is on my list. I do have complete access from inside the building but unless that wire was stranded, I'd be worried about breakage. Everything I've seen so far says to nail them to solid lumber. If it ever stops raining I'll be able to get the 1xs up there. Choices are dried tulip poplar or green oak.
Wires, eh? Hmmm....PAHS Designer/Builder- Bury it!
yeah, part of the "roof-top tour" (add'l $14 over reg. admission but well worth it for anyone interested in the building trades- we have annual passes since we live here and go every couple months to see what's in bloom, etc) includes actually going into one of the attic spaces and seeing how the slate shingles were attached. it's held for over a hundred years so far. i can't remember if it was iron or copper wire (seems like copper would have had a galvanic corrosion conflict so probably iron), but it was definitely single strand and surprisingly light guage.
if you're gonna be out this way be sure to let me know- my wife and i have been so many times we know where all (or at least alot) of the good stuff is. the rooftop tour also goes a few places outside the bounds of the regular self-guided house tour, too- not just up on the roof. heck, i think you need to visit soon as 'research' for this job and write it off as a business expense! when shall we be expecting you?
m
heck, i think you need to visit soon as 'research' for this job and write it off as a business expense! when shall we be expecting you?
LOL Pretty hard sell for a southerner don't you think? DW was just down in Boone and surroundings. Keeps telling me I have to see it. She's there 2-3 times/yr for work. But her van's so packed I'd have to ride on top. Asheville area, sight unseen, was actually our second choice for location. Never got that far.
Client I built the PAHS house for had a family reunion at Biltmore. Seems there was once an ownership in the family, but I don't remember the details. He didn't come from the monied side.
Gonna finish this roof first, if it ever dries up enough to get back up there. Fall a good time? DW is free every Dec, but that might be a tad late.PAHS Designer/Builder- Bury it!
fall is, of course, spectacular here. can be a bit crowded at the height of the foliage season but early on weekdays isn't usually too bad. if you're big on Christmas (dw and i ain't), nobody makes it a bigger deal than the biltmore- except maybe the White House. i think they only have rooftop tours april? through october? keep in touch.
m
keep in touch.
Will do.
Would you mind asking about those rooftop tour dates next time you're out? I'll talk with DW when she gets back from tidewater (Va). IIRC, there's also a dome down there that's sometimes open for a tour. Also met a furniture maker from there at a national woodworkers conference a hundred yrs ago.
Definitely won't be Christmas. That holiday makes me long for socialism. <G> And my 94 yr old mother winters in Williamsburg, another hot Christmas spot. If we didn't show up one year, it'd likely be her last. Actually, we did miss one year but we had a good excuse. Spent that Christmas eve in Bethlehem. But that was back when y'all were waiting in gas lines. If you're old enough to remember.PAHS Designer/Builder- Bury it!