Cedar Shake/Shingle redo

[fromrfarm]

Good evening all.. Quick question. I have been asking around locals here and doing some research on redoing my barn exterior; which is old pine shingles in rougher shape. Now this barn is big; 40x55 and four stories from the basement up(56') so we are taking a LOT of shingles. 

I see no reason to not simply reshingle right over the existing; using the appropriate length of nail/staples. Has anyone done this or see some reason why not too? Few lovals have board and battened, done steel over the old shingles.

Thanks in advance,

Matthew

[beenthere]

Show us some pics, then we can likely give you a much better answer. 

[Tom King]

Wooden shingles need to breathe to be able to last their best.  Unless there is a big protective overhang, I would only want them on open purlins.  For walls that tall, I wouldn't expect enough overhang to protect them.  Purlins should take up no more than half the space under the shingles.  In other words, for 6" exposure, purlins 3" wide with 3" open space.

Pictures would be a help.

[fromrfarm]

Pictures tomorrow! Will use a ventilated underlay over old shingles to ensure there is an air gap. The overhang is 2' give or take.

[fromrfarm]

 

 

[fromrfarm]

Smaller addition is a timber frame rebuild 17x32 so that gives you some idea of the size. I did board on board on that but would really prefer to do shingle instead of steel as long as I can get 50 years out of the shingles (given the size of the project). At the moment I am waiting on pricing of bulk shingles which isn't going to be cheap. 

[beenthere]

If you remove the old shingles, what is underneath? Will a backside pic taken from inside reveal the answer? 

[Tom King]

I think that kind of ventilation stuff is wishful thinking.

I have Cedar Shakes on the original part of our roof that are 43 years old and still look fine.  They are on open purlins.  If you install them according to the Cedar Shake and Shingle Bureau, you will be lucky to get 25 years out of them around here.

They're going to get soaking wet.  The important thing is that they can dry back out.

You're going to have to scaffold that up anyway, so it's not that much trouble to pull the old shingles off.

Nice barn!  The shingles look good in that picture.

[fromrfarm]

If you remove the old shingles, what is underneath? Will a backside pic taken from inside reveal the answer?

Old 1" thick boarding in.. Hemlock primarily.

[Tom King]

Breathing might not be as critical as on a roof, but I would still remove the old ones.

[beenthere]

With no pic of the inside sheathing, I also go with removal of old. You asked.. 

[fromrfarm]

Yep I did but all changed.. Probably doing steel right over it as much as I do not want to(after strapping). Got the cost for 2nd clear cedar shingles 

    Bare: $52 a bundle (25 sqft) - cost not including install (me), trim, fascia, soffit etc ; $10, 400 - bought these precovid $19 a bundle
    Prepainted: $297.37 a  bundle (25 sqft) - cost not including install (me), trim, fascia, soffit etc ; $59, 473.40

    Just insane. I built a the new section myself all in for $9,700. I will either mill my own shingles and paint, go board and batten, or steel. Will get pricing over the next few days.  

    Really wanted to stay true to the original building look but at those prices there is no way. 

[Tom King]

I make Cypress shingles for historic houses around here.  I use a 24" woodworking bandsaw running 10% overspeed with a VFD.  I made a sled that I can push them through on, turning a board of the length I want the shingles into 2 shingles.  I tried it both ways, and it's Much faster to push them through like this than vertically.

Using a Lenox 1" Woodmaster CT (carbide tip) 1.3 TPI blade.

We set a tablesaw out in the yard without a fence, and I rip the sapwood or juvenile wood off by eye with a helper finishing the cut on the output side of the saw.  He lays them on sawhorses.  Beyond the sawhorses is a 12" miter saw screwed to a sheet of plywood with a stop the length of shingles.  I wire the switch on so the saw doesn't stop running until I unplug it.

Boards are 10' to be easy to handle.  Helper slides board in place against the stop, with my left hand I slam the 100 tooth blade through it cutting a section of board to the shingle length.  He hands me the last piece, and I place it and cut it to length.  We're working fast, but no hands ever get anywhere close to the blade.

Another helper takes the pieces now cut to length off the table and stacks them near the infeed side of the bandsaw.  When that stage is full, I stand in place to push the board piece through to cut two shingles.

I pull the sled back, one helper sets a board on it, and the other helper takes the two shingles I just cut.
The sled doesn't let my hand get anywhere near the blade.  I hold the board against the fence with a stick in my right hand, and my left hand pushes the sled.  It will cut two 28" shingles as fast as I can push them through, which is a couple of seconds.

Second helper takes the two shingles right after they're cut, and stacks them in the back on my pickup.

I don't worry about counting shingles or how many are in a square, or how many squares we cut.  We take them in the truck to where they go.

We can go from boards on the trailer to a pickup full of shingles in a little over an hour without really getting in a hurry.

The sled is adjustable to cut any shingle thickness and taper we need.

You can't touch that speed with a mill.

[Tom King]

My first shingle making sled was guided by a 72" T track and a couple of slugs under the sled.

If I ever get another shingle making job, I have some lineal bearings and rods to make one.  We had to stop every 15 minutes or so to blow out the T track and lubricate it.

The sled itself is just made out of plywood with a couple of short T tracks running perpendicular to the long track holding the plywood fence for adjusting the thickness and wedge of the shingles.

The 24" bandsaw is a Centauro I bought off of CL for $600.  That's a beast of a saw and plenty good enough for this work.  They come up fairly often on CL.

I make shingles four times the length of the exposed part.  For 7" exposure, I make 28" shingles.  6"-24".  For siding shingles, 3 would be plenty.

Medium crown stainless steel staples. They come up to 2-1/2" long.  One in the middle like the roofs that lasted over a hundred years.  The four times overlap lets me put another staple in the next purlin up the roof from the one the lower staple is in, and exponentially increases the odds of a trough crack if one splits.