Steep Slope: Old House Re-Roofing Part 2 - Installing Shingles

By Bruce W. Maki, Editor

Start:

Prior to shingling we spent several days tearing off the old shingles and adding an additional layer of wood sheathing. This can be seen in Part 1.

Starting With A Clean Slate: We completed the OSB on the larger roof face. Next the drip edge was installed, also running up the side edge (known as the "rake") as far as we could reach.

The lowest part was covered with Ice and Water Shield, and the felt was fastened over top.

At this point the roof was "dried in", so it would be well protected from rain. This stage is the most important goal in roofing, usually. Often this point can be reached in one day, but with all the extra work of laying the new OSB, this milestone took us almost three days.

Installing New Shingles:

I didn't take enough photographs during the first phase to fully describe the process of roofing. So I shot some more photos of the second phase, which appear later.

Phase 1: 

I installed this self-adhesive shingle starter strip.  With conventional three-tab shingles most roofers simply cut the tabs off some shingles. Some people just install a row of shingles top end down, but that's kinda lame.

I tried to make the starter strip overhang the drip edge by about 1/8", but it didn't work that way. This stuff is like trying to apply a 20 foot long sticker, and once there is a slight mis-alignment it's hard to fix. So I just cut the material back.

Now, y'all don't have to be as dumb as me when you use this product. That shiny black line... that is the tack strip, and its job is to stick to the shingles above it. The tack strip is supposed to be at the bottom, not at the top! Later, to correct my absent-minded mistake, I went back and dabbed some tar between this piece and the first row of shingles.

The Wall:

Where the lower roof met the wall, I installed a piece of step flashing over the starter strip. Every row of shingles must have a step flashing at the wall. It is installed on top of the concealed portion of the shingle. The idea is that any water that gets around the end of the shingle will be forced on top of the next shingle below.

What you cannot do is simply run a one long angled flashing up the corner before shingling. Water will eventually get under the shingles and possibly rot the roof sheathing.

When the first row of shingles was installed, I nailed another step flashing in the corner. Note that these are nailed to the roof, not the wall.

Also note that before installing the shingles I did the following treatment to the small section of wall:

• Applied a 12" wide strip of Ice and Water Shield to the corner joint.
• Applied a layer of 15# asphalt felt (tar paper) to the exposed wall.
• Fastened 1/2" thick polyisocyanurate foam to the wall, using ring-shank plastic cap nails.
• Taped the joints with special tape for housewrap.

After three or four rows of shingles were installed I nailed the roof jacks in place and laid 2x10 planks on them. Note the thin vertical strips of wood on the upper roof. I nailed some scraps of OSB to the roof to hold the tar paper in place. This worked very well and was faster than nailing the felt down.

The same thing from a different angle. Note how the step flashings go all the way up. Once I reached this point I had to shift gears and install shingles on the other face of the roof, because of the way I decided to approach the valley shingles.

A Problem:

I had to go away for a day, and when I came back I noticed that the Ice and Water Shield appeared to have shrunk and was not laying in the valley properly.  This was quite a problem, I figured, because if somebody stepped on the valley (very likely) their foot would probably tear the shingles and cause a leak.

Before continuing, I called W.R. Grace's toll-free technical assistance line (1-800-444-6459 option 3, or www.graceconstruction.com) and found out the cause. The representative said that if Ice and Water Shield was installed in high temperatures then it could easily be stretched. It was about 95 degrees when we installed these pieces, and the roof faces south. Not exactly a cool environment. They instructed me to slit the first piece and install another layer on top, being extra careful not to stretch it. It worked fine after that.

Their help reminded me of why I only use W.R. Grace brand of Ice and Water Shield. Grace invented a heavier version of this material about 35 years ago.  The original name was "Bituthene", which is pronounced just like "bitch-a-thane", and that has a whole set of marketing consequences, I guess. The heavier version is still called Bituthene, and is meant for waterproofing basements. The name of this roofing underlayment was changed to Vycor a few years back, which confused people, then they changed the name to simply Grace Ice and Water Shield. Well anyways, their patent expired a few years ago and many companies now make similar products.  Grace has years of expertise making this bituminous rubberized asphalt shingle underlayment, and their product costs a trivial amount more than their competitor's products. So why take chances? I've used other products and they didn't stick as well. (And no, I'm not being paid to promote W.R. Grace's products.)

I made decent progress along the small face of the roof. I did this amount in about an hour. The air nailer helped.

Note how the shingles run past the valley a ways. This is for the closed valley method. There are some rules to adhere to: No nails within 6 inches of the center of the valley. Keep the ends of the shingles 10 to 12" away from the center of the valley.

This last rule means that the first shingle in each new row must be chosen carefully to ensure that no ends of any shingles will land in that "forbidden zone".

Within a few hours I had the entire face shingled. Besides the first set, I only needed to install one additional set of roof jacks, thanks to our custom-made ladder stairs.

As I approached the chimney I decided to procrastinate, and deal with the details later. This worked alright, although there were a few small leaks around the chimney during some thunderstorms. But I did apply some pieces of 6" wide Ice and Water Shield to the junction of the brick and the roof.. It stuck to the brick quite well.

I later installed some snazzy flashing around the chimney, including the elusive and rarely-seen counter-flashing, which makes a truly impenetrable barrier to water.

I shingled up to the ridge and folded the shingles over. The folded-over part overlapped the old shingles on the other side, thus preventing leaks. Working under the lightning rod was no problem, I just lifted it up. Later I fastened the rod brackets with roofing nails.

Once the small face was done I turned to the larger face. Again I only needed two rows of roof jacks and planks, because of the ladders.

Important:

At this stage some planning needs to take place. At several points across the face I measured the distance from the peak down to the most recent row of shingles. Inevitably the shingles are not perfectly parallel to the peak. This won't be visible when there is 5 feet of roof remaining, but if corrective actions are not taken, the final row of shingles will appear to be tapered, which is just poor practice and looks unprofessional.

My approach was to measure down from the peak and make marks on the felt with a carpenter's crayon (a yellow Crayola will work) at 10 inch intervals (i.e. 10, 20, 30, 40 inches down from the peak). I did this at both ends of the roof. Then I snapped chalk lines between corresponding marks. This set of parallel lines made it easy to lay out the shingles in straight rows. I would simply judge by eye how close the top of the shingles were to the next line above. There were one or two rows of shingles whose exposure was tapered, but in the middle of the roof this cannot be seen. And architectural shingles help to hide flaws in layout.

Before I laid shingles into the valley I snapped a chalk line along the center line. As the row reached the valley, I would set the last shingle in place and use a pair of tin snips to mark the cut. There are plenty of details about cutting valley shingles later in this article.

The last row has to be high enough that the ridge shingles (which are single tabs cut from 3-tab shingles) will cover the nails. This means that the nails have to be less than about 5 inches from the peak. If not, another row of shingles would have to be installed.

Notes From Phase 2:

A Little Practice Makes For Rapid Progress:

In the second phase, I began installing shingles while completing the new OSB sheathing.

When I got to the last row of OSB sheathing, I had to remove the scaffolding and move the ladders below the roof edge. I simply put two ladder jacks on the heavy-duty ladders and lowered the 12' long 2x10 plank onto the jacks. Doing this rigging by myself was awkward. At this point the roof was "dried in" and ready to shingle.

In phase 1 there was a porch roof to stand on, so this ladder juggling was not necessary.

I installed the shingle starter strip and the first few rows of shingles. After 3 rows of shingles I installed the red steel roof jacks, which hold planks up to 2x10.

I set the first short section of plank on the jacks. I also tied my hoisting rope to the plank. Each roof jack has a hole so a nail can be driven into the plank, which keeps the boards from shifting.

Once the roof jacks and scaffold planks were installed, I moved the ladders so they leaned on the scaffold. I wanted to avoid leaning the ladders against the aluminum drip edge, because I know from past experience that drip edge gets bent out of shape and the shingles get damaged from the weight of a ladder. Once I reached this point I plugged in the pneumatic roofing nailer and went to town.

After a couple of hours of working by myself, I had about half of the larger face shingled.

Once I had reached the valley I shifted my attention to the higher, smaller face. Those shingles will be run long, past the valley. I put a small piece of starter strip at the lowest edge of the valley (that little black piece). I could have used a shingle for this.

I commenced shingling on the small face, letting the shingles run past the valley. During this process I installed a second tier of roof jacks and scaffold planks. I located these so I could reach them easily from my 6' home-made ladder stairs.

It took me less than two days to reach this point.

Cutting The Valley Shingles

To mark the centerline of the valley, I snapped a blue chalk line. I had to drive a nail at the top end (beyond the shingles, of course) because I had no helpers. This line will be used as a cutting guide for the shingles on the other face. Blue chalk will wash off in the rain. I've heard that red chalk will not wash off.

To crop the valley shingles, I set the full shingle in place and used tin snips to nip the top and bottom edges where they intersected the blue valley centerline. Then I flopped the shingle onto the scaffold, face down. I curled up the shingle at the nips, placed a steel ruler against the curls, and cut the shingle with a utility knife. This method was quick and the cuts were nearly perfect.

Fitting Shingles Into The Valley: As each row approached the valley, I would lay a shingle in place (1) and examine how big the final shingle would be. The cut edge of the valley is at arrow 2. In this case, the final shingle would be too short, because if I kept the nails 6 inches from the valley centerline this fractional shingle would only be anchored at one end.

My solution for the above case was to use a shorter (i.e. partial) shingle for number 1, thus leaving me room for a larger final shingle. But... as mentioned earlier, care must be taken so the partial shingle's ends are not too close to the gaps below it. In cases like this I typically used a half-shingle in place of a full shingle. (You cannot do this with 3-tab shingles.)

The proper practice is to be careful when choosing the length of the first shingle in the row, to ensure that there would be no gaps too close to the valley. The usual method of starting rows (which works fine on a simple rectangular roof) is to begin a row with a full shingle, then a 3/4 shingle, 1/2, 1/4, and back to a full. But when shingling into a valley it's sometime necessary to use a completely different pattern for the initial shingles, as long as the gaps are staggered by at least 6 inches.

After everything was done, I lifted up each cut shingle at the valley and applied a bead of roofing cement (tar) to seal the edges. This should discourage water from creeping underneath.

Tying The Two Phases Together: Shingling The Ridge

Details: Ridge Meets Face

The first phase can be seen in the rear. This was tricky, because the shingles on the second phase did not line up perfectly with the shingles on the first phase. No matter how careful you are, this is a problem with roof faces that start out divided (i.e. at the bottom) and join higher up.

It might help to measure up from the drip edge or down from the peak, but there's no guarantee that the house structure is square and parallel.

Also, that red roof jack was left there for a reason... it will provide access when I do the flashing around the chimney.

I adjusted the exposure on some rows of shingles to get the two faces to line up as close as possible. The shingle I'm holding is important because it will cover the intersection of the ridge. The ridge "runs into" the other face of the roof, whose ridge is about 2 feet higher.

Looking at these pictures is like staring at camouflage. The red arrow points to the ridge. I'm holding up the shingle above (on the higher face). This shingle was not nailed normally, at first. I nailed it at the top so I could lift it up and work underneath. Later I nailed it properly.

To make the ridge blend in, I made a slit in the shingle that intersected with the ridge. Without this cut, the shingle would not lay flat. I suppose I could have made a V-shaped cut instead.

The last row of shingles just barely extended past the peak. I later trimmed back this slight overhang, because it got in the way.

This is a crucial test. I placed a ridge cap shingle in place to see if it would cover the nails of the row below. It wouldn't. (The other side of the roof was fine.) This meant that I had to install one more row of shingles.

I laid another row of shingles (1), which was folded over the peak. As I moved along, I nailed down the ridge cap shingles (2).

The ridge cap shingles are not the same as the rest. These are cut from plain ordinary 3-tab asphalt shingles. Some people use a utility knife to cut these, I used a pair of tin snips. If the weather was warmer (i.e. above 60 degrees F) a knife might have been easier. Note how the buried part of the shingle is cut with a taper. Simply cutting the shingles into 3 separate tabs doesn't work as well, because the cut edges would be visible.

Ridge cap shingles are bent over the peak of the roof and nailed in two places along the usual nailing strip. I kept the nails about 1 inch above the edges.

Shingling the ridge takes very little time. I did this 25 foot long stretch in about 45 minutes, and I took my sweet time too.

Final Details:

When I re-installed the brackets for the lightning rod, I applied a dab of black silicone under the bracket and the nail heads (red arrow).

The Results:

This is a photo of the first phase, after we: Replaced the beam in the porch roof. Added a layer of OSB to the porch roof and replaced the shingles. Replaced the siding above the porch roof. This picture was taken before the second phase was begun.

This is what it used to look like. I'd say it's an improvement. There were 3 different colors/styles of shingles on this house before we replaced the roof.

Some thoughts on architectural multi-layer shingles.

This newer type of shingle has really caught on lately, especially here in Northern Michigan where there are a lot of high-end vacation and retirement homes being built. But I've also been noticing these shingles on a lot of ordinary houses, too.

There are some benefits to architectural shingles:

• There are no tabs to break off in a strong wind.
• The random appearance makes mistakes easier to hide.
• You don't have to be concerned with the proper staggered tab alignment that is necessary with 3-tab shingles. Standard 3-tab shingles are 36" long, so each tab is 12" long. Each successive row of shingles has to be placed either 6" or 18" to the left or the right, but never 12" or 24".
• With architectural shingles some common-sense rules apply: keep the ends of the shingles (on adjacent rows) at least 6" apart. But you can separate the joints by any amount greater than 6". The instructions for these shingles (by IKO) say to cut 10", 20" and 30" off shingles to get the fractional shingles for the beginning of each row. Since these shingles are around 41" long, the cut shingles are essentially 1/4, 1/2, and 3/4 shingles. There is no reason why you couldn't use alternating full and half shingles at the beginning of the rows.
• A partial shingle can be used almost anywhere (if you're careful), so there can be less waste. It occurred to me that a person could shingle an entire roof with scraps of architectural shingles. It would be similar to wood shingles, which are often only a few inches wide. This odd idea should work as long as the gaps were kept apart by the required 6 inches. Now that would be a waste of time for most people, but leftover shingles could be employed for a small shed, for example, even using different color shingles scattered randomly.
• Based on the two roofs I have done using architectural shingles, I would say that they are easier to work with.
• The one major drawback (besides the higher cost) is the lack of flexibility of architectural shingles. Curving the shingles in the valley takes a bit more patience, especially when the shingles are cold.

Costs:

I was tempted to get a couple of quotes from local roofing contractors, just to see how much money we'd be saving. But I don't believe in pestering contractors for information when I fully intend to do the work myself.

But from my experience, I believe it would cost between $8,000 and $12,000 to have this house re-shingled by a roofing contractor.

Although at his writing we have only finished half of the roof, I can make a good estimate of material costs:

• Shingles, 20 squares, $33 per square on sale (we saved about a buck a bundle, or $3 a square). Total $660.
• 3-tab shingles for ridge, 3 bundles at $10 each. $30.
• Grace Ice and Water Shield®. We've used 4 squares so far, and we'll probably need 4 more, at $45 each. $360.
• 15# Tar paper (a.k.a. roofing felt). About 8 rolls. I can't remember the price, but it's cheap, certainly under $150 total.
• Box of coil nails for the roofing nailer, about $45.
• OSB. We've used 36 sheets so far, and we'll probably need 30 more. At about $8 a sheet (the price fluctuates like gas prices) this should cost about $530.
• Drip edge, 20 pieces (10' long) at about $3 each. $60.
• Assorted aluminum flashing materials, $40.
• Assorted nails, $50.
• Vent Flanges, 3, $15.

I come up with $1,940 for a total. So figure around $2,000 for about 2,000 square feet of roof (that's not the area of the house). A buck a square foot, including new sheathing. Not bad.

We also bought some tools for this job:

• Bostitch pneumatic coil roofing nailer, $300.
• Roof jacks, adjustable, 12 at $6 each. We already had another 12 jacks. Figure $150.
• Various 2x10 planks for scaffolding, about $40. Reusable.
• Materials for homemade ladder-stairs, about $40.

Time: Based on the first half of this project, I figure there will be 5 man-weeks of labor invested in this roof before it's all done. I would figure 200 to 250 hours, since I usually work more than 8 hours a day. That's a lot of time, but when broken into 4 quadrants it's not so bad. That works out to 8 to 10 square feet per hour of labor, but I work at a decently relaxed pace on the roof. Professionals probably are much more productive, but I don't care.

We could be saving around $6,000 to $10,000 by doing this work ourselves. That works out to between $24 and $50 per hour. I wish I cleared $24 an hour on a regular basis.

When you pay a contractor, you're not just paying someone's wages. You are paying for a lot of overhead costs like worker's compensation insurance (very expensive for roofers) and liability insurance, which covers them in case you sue them because they dropped a hammer on your head. You don't need liability insurance for yourself. Being self-employed, I'm prohibited by law from buying worker's compensation coverage for myself... I guess there's too much room for fraud in the system. If I hurt myself, nobody's going to pay my lost wages, but at least I have medical insurance.

Speaking Of Safety: Tips On Not Dying:

I would say that the biggest risk arises from climbing up and down the ladder to get to and from the roof. Climbing with tools in your hands is a really good way to lose your balance. That's why I insisted on using the buckets and rope for hauling everything.

The next greatest risk is probably the chance of losing one's balance near the edge of the roof. When working higher up the roof, there is little chance of falling off because there are several rows of planks to stop you.

There is another hazard during roofing: Getting hit by falling objects. It is necessary to throw things from the roof. In both of these phases of our project there were entry doors that people could walk out of and be struck by debris. Some common-sense rules apply:

• If you drop something while working on the roof, yell "Heads Up" so people have a chance to react.
• When you walk out a door in a danger zone, say something to alert people on the roof. I like to come up with creative things to say, such as "Don't shoot", "Hold your fire", or "Elvis has left the building".
• When you are about to hurl a large chunk of shingles from the roof, and you aren't sure who might be below, say something.
• People have a habit of coming and going from their houses and not being the least bit concerned about junk falling from the sky. Everybody around a re-roofing project needs to adjust their habits for a few days. Maybe posting a sign on the inside of the door will remind people. Or tie a bell to the door so you can hear it opening.
• Remember, it only takes 600 inch-pounds of kinetic energy to cause a fatal skull fracture. This means that a 10 pound object falling from 60 inches (that's 5 feet) can kill somebody. A 2 pound object falling from 25 feet can do the same.

See: Index of Roofing Articles

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Copyright © 2001, 2005 HammerZone.com

Written November 27, 2001
Revised July 12, 2005