Replacing old roof shingles. Steep Slope:

Re-Roofing An Old House - Part 1: 
 

In This Article:

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Skill Level: 3 (Intermediate)

Time Taken: A couple of days.

By , Editor

Start:

Replacing the shingles on an old two-story house with a steep pitch roof can seem pretty daunting. Or maybe it's just that roofing has a reputation as dangerous work. Numerous people have reacted with surprise when I've told them about doing this re-roofing project. They think it's terribly dangerous, that only special people can work on  such high and steep roofs, that there is a constant risk of falling off.

I've worked on at least half a dozen major roofing projects prior to this, some on steep roofs, some on low pitch roofs. In some ways I prefer working on a steep roof. For one, there is not as much bending over. And since roof jacks and scaffolding planks MUST be set up, there are designated places to walk and lots of places to grab onto. If you've ever worked on a low-pitch roof on a hot day, you know that by simply turning your foot on the shingles you can scrape bare a big patch of asphalt. This is not a problem with a steep roof, because you never really walk on the shingles.

However, the big drawback to steep roofs is the time needed to set up roof jacks and scaffold planks. There was probably one or two hours of scaffold setup for each quadrant of this roof. 

Note: After completing the first quadrant of this roofing job I realized that I needed more photos, so I shot many pictures during the second quadrant (done about 5 weeks later) that covered some topics I missed earlier.

 


Southeast Quadrant: Phase 1

The house before the roofing was replaced. There were three different colors or shades of shingles. It looked cheesy, to say the least.

Southwest Quadrant: Phase 2, done about 5 weeks later. 

But the real problem was that several areas of the roof had shingles that were badly curled or degraded. There was a small leak around the chimney, which was caused by inadequate flashing.

 

The siding next to the roof had problems with paint peeling. On closer inspection we discovered that many of the boards were split or soft from water damage.

And during some previous roofing job, somebody had placed step flashing in front of the siding, rather than behind. Not wise.

 

The chimney was a mess. Note the grayish-looking tar around the base of the brick. Previous owners have simply piled on more roofing tar to patch the joint, rather than repair it correctly with metal flashing. They also slathered tar on some cracked bricks. Lame.

This house is shaped like a plus sign (+), with four gables and two main ridges that are perpendicular to each other. This arrangement made it logical to approach the re-roofing job one quadrant at a time, with the ridge making an obvious stopping point. Many roofs can be done in sections. A simple gable roof could be done one half at a time, with the ridge being capped at the end.

 

Roof Tear-Off:

See Installing Roof Jacks For Safe And Easy Access

Some people, including myself, sometimes have a reluctance to get started on major projects like replacing a roof. There are a lot of things that could go wrong, such as having a sudden downpour when all the shingles have been ripped off. And it takes some work just to set up the equipment needed to work on a steep roof.

The first step in any steep-roof shingle job is to install roof jacks and planks. Once there is a firm platform to work from, it becomes much easier to jump right in and start tearing off shingles.

This first quadrant had the advantage of a porch roof located just below the house roof. The porch roof has about a 6:12 slope, which made it safer to walk on.

The presence of the porch roof made everything seem easier. We could haul materials up to the porch roof for staging and storage. Note in the above photo how the ladder is tied to the scaffolding with a rope. There is nothing more frustrating than having the ladder tip over and leave you stranded on the roof. Also, that rope made a very good "handrail" to grab while climbing up or down from the roof.

 

Surface Preparation: Several Problems Arise:

Those whitish-looking narrow boards... I believe those were the original roofing strips when the house was built. In 1907 most houses were roofed with cedar shakes, not asphalt composition shingles. Wood shake or shingle roofs do not require a full deck of sheathing, only narrow strips of wood spaced about 6 inches apart. At some point in the past century they added wood planks between those narrow boards.

 

The old solid wood sheathing had many holes like these.

To our surprise, the entire roof deck was a mess. There were large gaps between boards, there were boards with large chunks missing, and the worst flaw... many of these narrow, older strips were considerably thicker than the wider boards, so the roof deck was not uniform and smooth but had high strips in places.

We contemplated the problem and decided to add a layer of Oriented Strand Board (OSB) on top of the existing roof sheathing, but only after the thickest narrow boards were removed.

OSB is not my favorite material for roof sheathing. I would prefer plywood, but it costs about twice as much. One drawback of OSB is its tendency to swell when it gets wet. Wet OSB will rot faster than plywood under similar conditions. Also, if the panels are butted tight together, they won't be able to expand and the edges will swell or buckle upwards, leaving unsightly ridges visible through the shingles.

But... OSB is very reasonably priced, around 8 bucks a sheet for 7/16" thickness. If kept dry by a careful roofing job, OSB should last a very long time. We ran over to Home Depot the next morning and bought 20 sheets of OSB for this quadrant of the roofing project. This new decision cost us a lot of time and a bit of money, but eliminated the potential for numerous headaches later on. By the time we were finished, we were glad we decided to add the extra OSB sheathing.

When we tore off the shingles around two sides of the chimney, we were surprised by how high the previous owners had piled on the tar. There was about a three-inch deep layer of shingles and hardened goop around the chimney... but no metal flashing.

 

The lightning rod was less of a problem than I anticipated. We simply removed the nails that held down the brackets and lifted up the rod whenever we had to work beneath it. We also unscrewed the air terminals, which are the spires that point upwards.

 

At the ridge we removed the cap shingles.

 

We removed the shingles on the other side (the left side) to expose a small strip of bare wood. Later we covered this bare strip with tar paper for a good temporary fix. Since we are doing this roof one quadrant at a time, we can't remove any more shingles on the other side.

 

That home-made ladder/stairs came in very handy for all sorts of roofing work. It allowed us to just walk right up the roof with no more effort than climbing a flight of stairs. We removed the shingles all around the ladder, and then moved the ladder over to take care of that last spot.

We made several of these ladder/stairs. The one in the picture above was 9 feet long (and kinda heavy), and we also made a 6 footer and a 3 footer. Later in the job we amputated the 9 footer into a 6 and a 3.

Getting into the valley was not so simple, however. Since the ladder/stairs had to be placed against a roofing scaffold, they did not provide access to the valley areas.

So we just nailed some 2x4 and 2x6 cleats to the roof. The nails were big 16d spiral nails, and they were always driven into the rafters. Locating the rafters was easy because we could see them in the gaps between the boards.

 

It was pretty easy to sit on the ladder/stairs and work on shingle removal.

We made a minor mistake when we started setting up the roof jacks. There are two rows of red roof jacks quite close together on the larger roof face. This would only be necessary if these ladder/stairs were not used. I'll point out that stepping from one scaffold plank to the next is quite taxing on the legs. But that's the primary way I've seen roofers do it.

 

Notes From Phase 2 -
Start At The Top And Work Downwards:

When we did the second quadrant, we each worked on a roof face and peeled off the shingles in a horizontal band. The idea was to never leave too much bare roof sheathing exposed to the elements. This section was done in September, when there is greater likelihood of wet weather.

 

We pulled up many of those narrow boards, which left thin openings in the sheathing. You can see the pink fiberglass insulation through these gaps.

The second phase went faster because it was slightly smaller, but mostly because we had the fresh experience of the first quadrant to guide us. Our strategy was:

  • Remove a horizontal band of shingles a bit wider than the 4 foot width of the OSB.
  • Install a row of OSB starting at the valley and working towards the rake.
  • Cover that new row of OSB with tar paper, leaving the lower edge un-stapled so we could later slide the next lowest piece of tar paper underneath.
  • Repeat this process until we reached the bottom edge of the roof, and then work back uphill with shingle installation.
  • There's a catch with this approach: the Ice and Water Shield for the valley. We made some mistakes in the first quadrant that cost us some time.

 

Cleaning Up The Surface:

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Many original nails had worked loose. Some nails got caught in the shingle removal scraper tool and were pulled up, like this one.

I would say that almost all of the nails in the roof sheathing were at least a little bit loose. I am convinced this is a factor in the deterioration of many old wood-frame houses, because it lets the entire structure sway in the wind. This swaying is called racking.

 

This roof had thousands of small rusty nails that had been bent over into the wood. I suspect these may be leftovers from the previous wood shake roofing materials.

We spent several hours picking away at these. Often we could just drag the claw of a hammer over the nails and they would break off. Some needed to be yanked out. It was time-consuming picky work, but we wanted to remove all obstructions that would hold the OSB away from the old sheathing.

 

There were a lot of old roofing nails under the shingles we tore off. The previous roofers hadn't even bothered to pound in many of these.

 

The flat pry bar was an essential tool for removing these nails.

Most professionals just whack these nails flat, but eventually the sheathing is peppered with these things, which seems to help make the wood crack. We're not interested in helping an old house deteriorate, and since our time is far less expensive than any paid professional's, we chose to take some time to clean up these nails.

This is one of many examples of how a do-it-yourselfer can exceed the quality level of work done by most professionals. They'll say what we're doing is not necessary, a waste of time, and that they can't afford to do it. But I've seen boards that were destroyed by these old nails.

 

Shingle Disposal:

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To haul away the shingles, we parked a small utility trailer just below the roof (it's hard to see... right behind the Jeep). We were able to throw a lot of shingles directly into the trailer. Every few hours we picked up the shingles on the ground and loaded the trailer.

Disposing of shingles can cost a small fortune in some areas. I have heard of shingle removal costs reaching well into the four-figure range. The dump in our area charges about $32 to dispose of the contents of this small 4'x8' trailer, loaded about 18 inches high.

Also note that when traveling with an open trailer (or truck) of construction debris a sturdy tarp should cover the load. Here in Michigan you are eligible for a nice ticket if the police catch you with an uncovered load that exceeds the sides of the trailer.

And... be aware that shingles are very heavy. This little trailer can carry only about 900 pounds, which is about 4 squares (400 sq. ft.) of conventional shingles at single thickness.

We bought a magnetic nail picker-upper tool for about $25. You slowly roll it around the lawn and it picks up nails. This was an excellent purchase... fixing a flat tire costs $10 or more, why take chances. Besides, if the lawn mower kicks out one of these nails it could cause serious injury.

 

The Hard Part: New Sheathing

Adding a layer of OSB definitely slowed down our progress, but was worth the effort.

We worked from the top down, and we applied a sheet of 15 pound felt (tar paper) as soon as a full row of OSB was laid across the face of the roof.

It's important to leave a small space between the panels, or else the edges will buckle later on and small ridges will "telegraph" through the shingles. I've seen it before and it's a dumb thing to have happen just because you forgot to leave a little gap. We simply used 2 nails for spacers when positioning the panels.

To provide a sort of "back-stop" for the top row of OSB, we nailed some scraps of wood to the other side of the roof, just over the peak. We could simply push the OSB panels uphill until they hit the stops, and there was no worry about positioning the panels vertically. Then we could just drive a couple of nails right below the panel to stop it from sliding, and tap it into place.

 

Nailing:

For most of the OSB on the first phase we used 3 inch nails in a nail gun. Otherwise we used 3 inch galvanized spiral deck nails. Of course, the goal is to drive the nails into the rafters, not just the old sheathing. We spaced the nails about 8 inches apart.

One problem with our framing nailer is that it often blows the nail head halfway through the OSB. Dialing back the air pressure on the compressor doesn't always solve the problem, so for the second phase we just hand-nailed the sheathing. That didn't really take much longer. The main benefit of the nail gun is that it doesn't make my tendonitis flare up like hammering does.

 

Notes From Phase 2:

The plan was to install OSB in a band while much of the old shingles remained in place. It wasn't quite as simple as that. We went ahead and tore off all the shingles from that smaller face on the left of the valley.

 

Working around the plumbing vents was not a problem. Luckily the OSB panel ended right beside this pipe. The pipe is 3" PVC that was installed a year before to correct an inadequate venting problem. I had painted it black at the time, but our roofing work scraped off some paint. At the end of the job I applied another coat of oil-based black paint. 

My view is this: Why not take 5 minutes and paint these glaring white PVC vents black so they are not so visible?  I've never seen a professional roofer or a plumber do this, yet it makes the house look better and costs next to nothing.  Can you see the two PVC vent pipes in the picture below? One is white, just below the center of the photo, and the other is black, just right of the left-hand gable peak.  See what I mean about black-painted vents blending in better?

We focused our efforts on the smaller face.

The upper scaffolding on the large face just happened to interfere with our second row of OSB.

 

When this scaffold was removed, it was possible to lay the second row of OSB close to the edge of the old shingles (red arrow). This made a logical stopping point for the day, as tar paper or tarps could be quickly stapled down to overlap the old shingles, making a water-tight temporary covering.

 

We just quickly laid some tarps over the open roof, because the forecast was expecting clear and dry weather.

The next morning we completed the OSB on the smaller roof face. This was a critical goal because then the Ice and Water Shield® could be installed in the valley, which simplified the installation of the tar paper.

 

This roof is unusual because there is a small crown molding (arrow) at the top of the fascia board, but the original roof sheathing didn't reach this trim, so the crown just hung there, fastened only at its bottom.

 

We corrected that by driving short deck screws to fasten the lower edge of the OSB to the crown molding.

 

Meanwhile, Back In Phase 1:

To remove the last shingles on the higher face, I stood on a plank rigged up to a ladder. This could be dangerous if not done right. The left end of the plank was screwed to the roof scaffolding, and the base of the ladder was secured with 4 large wood stakes, which prevented the ladder's base from moving sideways or away from the house.

 

At this point there was new OSB and felt down to the upper scaffold, and the old shingles below that. As long as the felt runs over the edge of the shingles, rain will stay out.

Note how we laid Grace Ice and Water Shield® in the valley, working from the top down. This didn't work well, because it was a chore to leave the lowest 6 inches un-adhered and later slip the next piece below it.

In this sectional manner a roof can be replaced over a period of several days or even weeks. The biggest risk, from my experience, is that wind will rip off the tar paper and let the rain into the gaps between the panels of OSB. I certainly would not try this approach during the late fall and winter months.

 

Details - Where Roof Meets Siding:

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Later, we removed the siding from the small triangle-shaped section of wall above the porch roof. We tried to salvage some of the siding by cutting the nails with a reciprocating saw, but it didn't work. Most of the boards just cracked.

 

Phase 2 had a smaller triangular section of siding to replace.

We nailed a strip of aluminum flashing to the corner joints. The main benefit is that the Ice and Water Shield® has superior adhesion to the metal compared to old wood. We later applied a 12" wide piece of Ice and Water Shield to the corner joints.

 

At the last row of OSB, we had to be sure the panel edge lined up with the existing edge of the roof, or else there would be problems later  installing the aluminum drip edge.

The width of the last row of OSB would have been around 2 to 3 inches. The old roof did not have enough structure to fasten such a narrow strip of OSB. Our solution was to install the full width sheet aligned carefully with the edge of the old roof, and then fill in the narrow strip above.

 

Details - Drip Edge, Ice and Water Shield®:

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Once the last OSB was fastened, we installed the drip edge.

The corners were formed by cutting the drip edge with tin snips and folding over a small tab.

 

The drip edge has been installed on the lower edge and the rake (the sloped edge).

 

We nailed a strip of aluminum flashing in the valley. We used 6 inch wide metal here, but 10 or 14 inch would have been better.

To make the fold, we simply cut a strip about 7 or 8 feet long, sandwiched half of its width between two 2x4's, and bent it by pressing the exposed half against another board.

My main reason for using metal in the valley is to provide some structural strength over the small voids between the panels, and to provide an excellent bonding surface for the Ice and Water Shield®.

We applied a sheet of Grace® Ice and Water Shield® to the valley. This first piece was over 6 feet long and was difficult to handle. Four-foot pieces are easier to work with.

The next sheet overlapped this one by about 6 inches.

 

Then a  sheet of Ice and Water Shield® was applied at the edge of the roof, carefully overlapping the valley sheet.

Note how the tar paper was flipped up. After this, we stapled the tar paper so it overlapped the Ice and Water Shield® properly.

 

Sticky Dilemma:

If you've never worked with Ice and Water Shield® before, well, you're in for a treat. It's quite a challenge to work with this super-sticky film. It sticks to skin fairly well, it sticks to wood reasonably well, it sticks to metal very well and it sticks to itself irreversibly well. 

In other words, if you remove the backing paper and a corner folds over and sticks to itself, you cannot get it apart. Period. I've had to throw away long sheets of this product because I let it droop and it contacted itself. This product can be very frustrating, but it's worth the hassle.

The instructions on the box describe some techniques that work quite well, such as tacking the corners and peeling the release paper back from one end to the other. I've had good luck just unrolling the sheet while peeling away the release paper, smoothing with my right hand as I peel with my left. It takes practice. Buy extra.

 

All Downhill From Here...

After the valley details were complete, we continued tearing off the shingles on the larger face.

 

We discovered that the previous owner had patched the sheathing around the plumbing vent when he replaced the shingles.

I noticed a potential problem at this point. The distance from the new OSB to the edge of the roof was about 50 inches, 2 inches wider than a sheet of plywood. I could install a narrow strip and then remove the lowest scaffold, but that would mean  hoisting large panels up there by myself, as my helper had left.

 

So I ripped some OSB in half lengthwise and nailed them down. The next row would be about 26 inches wide, not too wide to handle solo.

 

This turned out to be the wise choice, because I was able to get the tar paper installed to this low point, and work around the vent pipe too.

 

Then I took a few minutes and moved the ladders around. I set up ladder jacks on two humongo type 1A 28' ladders (I can barely move these beasts, but they sure are stable) and used the lesser ladder to access the extension plank that I laid on the ladder jacks.

This method of access is a pain because it requires three ladders... two to hold the plank and another for access. When the ladder jacks are outside of the ladders, you must use a third ladder to reach the plank. When the jacks are under the ladders, you do not need a third ladder for access. But I couldn't use that approach because I would be standing directly below the soffit.

With the roof jacks and scaffolding removed I was able to lay part of the last row of OSB and install new drip edge.

 

I wanted to do as much work as possible before moving the ladder/jack/plank apparatus down to the next chunk. Without a helper it took a long time to move this stuff.

 

I managed to install the self-adhesive starter strip and the first row of shingles before moving the ladders. But this wasn't enough to prevent a second moving of the ladders, because I needed to get three rows of shingles laid before I could install the roof jacks again.

 

After I moved the ladders, I was able to install the last section of OSB, then the drip edge, etc.

At this point the roof deck preparation work was complete, and I was ready to commence shingling.

I would estimate that getting to this point consumed at least two-thirds of the total time we spent replacing this quadrant of roof. It took about 5 days to reach this point (for each phase), and I had the home owner to help me for two of those days. That's about 7 man-days for 600-700 square feet of roof surface. We could have worked more hours each day, had this been done in late spring when the days are much longer than late September.

I nailed down a few partial rows of shingles and installed the roof jacks in about the same location as during the tear-off.

 

Continue reading the last few points or jump to: Installing Shingles

 

Tips And Techniques:

Hoisting Materials And Tools:

We used a 3/8" rope with a large hook on the end to haul almost everything up to the roof. This worked great for hoisting buckets full of tools and sheets of OSB. 

To lift panels, we just clamped a C-clamp to the middle of the top edge of a sheet, and looped the rope through it and hoisted it up. This is much safer than trying to climb a ladder while carrying a sheet of plywood.

 

The C-clamp made a convenient handle for carrying sheets of OSB across the roof.

By resting the sheet against a ladder, the sheet didn't spin as I pulled it up. Without the ladder, a corner of the sheet can get caught under the soffit, making hoisting difficult.

Years ago I was building an addition by myself, and while trying to place a sheet of plywood on the roof, the panel caught the wind and started sliding down the rafters, making a bee-line for my neck. With visions of a "plywood guillotine" in my mind, I knew there had to be a better way. 

By hoisting things with the rope I could always just let go if something went awry, and since nobody is allowed to stand under the item being hoisted, nobody could possibly get hurt.

To bring tools to the roof we just loaded them into a 5 gallon bucket and pulled them up. With this technique, you can keep both hands on the ladder while climbing.

 

We used the rope to raise and lower planks. We just drove a couple of nails into the narrow edges near the end of the board and looped the rope around them.

Just as with all industrial and construction work, absolutely NOBODY is allowed to walk or stand under ANY object being lifted. If there are children and pets in your household, keep them away from the hoisting areas.

 

Clothing:

Working on a steep roof is very hard on the seat of your pants because of the need to sit against the roof at times. Rather than destroy good blue jeans, I wore very old pants that were almost ready to be cut into rags. This roofing job just finished them off. It pays to hang on to a couple of pairs of old jeans with holes in the knees.

Here's a tip I learned from a roofing project years ago... keep a couple of 5-gallon plastic pails handy for storing tools and supplies. We tied the pails to the steel roof jacks with bungee cords and dog leashes.

 

Safe and Easy Access:

We found that the ladder/stairs created an extra level of safety that made climbing up and down the roof no more scary or strenuous than using normal household stairs.

I got the idea from a picture in a book that showed some roofers using a short section of a wooden extension ladder. They had laid the ladder against the roof, bearing on the scaffold plank. But the round rungs appeared to provide nothing more than a place to rest one's foot, not a comfortable work platform. I reasoned that I could fabricate a similar device from 2x4's, 5/4x6 deck planks, and Simpson Strong-Tie angle brackets. Note that these stairs were made to work on the 12-in-12 slope of this roof (i.e. a 45 degree angle) and would need to be modified for other roofs.

 

Roofing Work - Tips On Not Dying:

I would say that the biggest risk from roofing work 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 accidentally 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 something 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.

 

HammerZone's Recommended Roofing Tools:

 

 

Continue To: Installing Shingles

 

 

Tools Used:

  • Shingle Removal Tool
  • Pitch Fork
  • Pry Bars
  • Basic Carpentry Tools
  • Circular Saw
  • Roof Jacks and Planks

Materials Used:

  • Oriented Strand Board, 7/16" thick, about 36 sheets for half of the roof.
  • Grace® Ice and Water Shield®, about 3 squares.
  • 3" Galvanized Spiral Deck Nails
  • 3" Common Nails (for nail gun)
  • 1-1/4" Roofing Nails
  • Aluminum Drip Edge
  • Self-adhesive shingle starter strip

 

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Copyright © 2001, 2005 HammerZone.com

Written November 26, 2001
Revised January 15, 2005