 |
Replacing Asphalt Shingles:
Part 1
Tearing Off The Old Roof
|
In
This Article:
|
Related Articles:
|
| Skill Level:
2-3 (Basic to Intermediate) |
Time Taken:
About 6 Hours |
By
Bruce W. Maki,
Editor
Start:
| These first
two pictures were taken on the south side
of the roof, in the fall of 2007, a year before
I replaced the roof on my garage. The shingles
in some areas were in fair condition, but a
couple of sections were ridiculously worn out. |
 |
|
 |
A closer view of the worst area. Frankly, I'm
surprised the roof didn't have a worse leak. At
this point the shingles were about 28 years old.
There was nothing left of the shingle tabs but
little flaps of tar paper.
I took these pictures when I did a
quick-and-dirty patch job with a couple
gallons of tar. That patch worked very well...
it stopped the leaks and lasted for almost a
year. |
|
When I tore off the south side
shingles, the plywood was dry. Luckily there was no major
water damage to the roof plywood from years of leaks. There
were just a few spots where the plywood had water marks, yet
the wood was strong and intact.
| The shingles
on the north side were in much better
condition, although they had started to curl.
Oddly, these shingles had no tar strip
below the shingle tabs, which is meant to keep
the tabs from lifting up and breaking in strong
winds. Up to this point I didn't know they made
shingles without tar strips. |
 |
|
 |
This was the worst shingle on the north side of
the garage. |
|
| I spread out
some tarps and old sheets of plastic on the
ground below the roof. Past experience has
taught me that there will be lots of nails and
small bits of shingles that will be very
difficult to clean up without some tarps. I
parked my small utility trailer close to the
garage, so I could throw shingles directly into
the trailer.
My garage roof was so low that I could easily
reach it from an 8-foot stepladder. |
 |
|
Note the small squares placed at the
corners of the tarps. Those are patio pavers... but they
aren't concrete, they are made from rubber. I bought some to
try, but I hadn't installed them yet, so I used them to
weigh down the tarps. They worked great because they are
heavy, flexible, and so thin that I didn't trip over them.
Normally I would use anything available that is cheap and
heavy, such as pieces of concrete, scraps of wood, or rocks.
 |
To make disposing of shingles easier, I lined my
4x8 trailer with a sheet of plastic. This should
keep nails from falling through the gaps. I used
spring clamps to hold the plastic in place. |
|
| This is a
shingle scraper, which is just a special
shovel with teeth and a heel for
prying shingles up. I bought this tool at Home
Depot several years ago for about $35. In a
pinch, a flat-blade shovel or a pitch-fork can
also be used, but they aren't as fast as this
tool. |
 |
|
 |
I started the tear-off procedure in the upper
corner of the roof. It seems to be faster to
work from the top down, but it's harder work.
If I worked from the bottom up, it was easier to
pull off the shingles, but it seemed that the
nails usually stayed in the roof. |
|
| I made sure
to get the scraper under the original tar paper,
so the whole works would be pulled up. Prying
at this jagged angled edge of shingles was
less effective than just working across the
top, removing a strip of two or three shingles
at a time. |
 |
|
 |
After removing shingles, there were LOTS of
nails sticking up. |
|
| I just used
the shingle scraper to get under the nail heads
and then pop them out. This worked fairly well,
but a pry bar works just as good. |
 |
|
Most builders and roofers just leave the old
nails in place and hammer anything that sticks up. I don't like that
approach because there have been plenty of times when an old nail
interfered with something. I just take a little time to get rid of
the old junk.
 |
I used a hammer and this medium-size prybar to
dig under the nail heads. |
|
| Then the
roofing nails were easy to pry up. To make
this job go faster, I used a bench grinder to
sharpen the beveled edge on this prybar. A sharp
edge made it easier to get under the nail heads. |
 |
|
 |
After prying up a bunch of nails, I used this
rolling magnet to pick up the nails. I suppose I
could've just swept the nails over the edge, but
this way I avoided kneeling on any stray nails.
It's also good to do any clean-up chores that
reduce the chance of tripping while working on
the roof. Loosing your balance is one way of
falling off the roof. |
|
More Nails For The Roof Sheathing:
When this garage was built in 1979 they
fastened the roof sheathing with nails that have really small
heads. And they spaced their nails about 10 to 12 inches apart.
| I didn't
think the original nailing was adequate, so I
used my nail gun to add some more nails. I drove
2-3/8" nails about 8 inches apart, closer when
nailing the edges of the panels. Using this
Paslode cordless framing nail gun is kinda slow
compared to a pneumatic nail gun, but it's much
faster than hand-nailing. It took me about 30
minutes to nail off each side of the garage
roof. |
 |
|
 |
Instead of trying to juggle a heavy roll of felt
while working on the roof, I cut the felt into
shorter strips on the lawn. I used a block of
wood to weigh down the end, then I unrolled the
tar paper alongside a tape measure.
Using a scrap of plywood for a cutting board
and a level as a straight-edge, I cut the tar
paper with a utility knife. |
|
| After
ensuring 2 inches of overlap with the previous
row, I stapled the lower corner of the felt to
the roof and unrolled it. |
 |
|
 |
When the felt was unrolled about 10 feet, I
adjusted its position (to make it parallel with
the previous row) and stapled it down with a
hammer-tacker. |
|
| It only took
about half an hour to apply felt to each side of
the garage roof. This is the goal of the
roof tear-off procedure. Once the shingles
are removed, the roof is covered with tar paper
to protect the building from rain. While tar
paper is certainly not a permanent solution, it
can withstand a few months of sunlight before it
seriously degrades. Withstanding the wind...
now that's another story. |
 |
|
 |
To hold down the sides better, I fastened the
edges with roofing nails. |
|
Cleaning Up
Afterwards:
After the tear-off was complete, I piled the
shingles in my little trailer and hauled them to
a local waste disposal transfer station. Since
my trailer could only handle about 900 pounds, I
hauled the shingles away right after tearing off
one side of the roof. (I installed the
new shingles on the south side before tearing
off the north side.)
Before picking up the tarps, I ran my rolling
magnetic nail picker-upper over the tarps to
pick up any loose nails. I put the nails in an
empty paint can for metal recycling. |
|
|
My local disposal company
charged me $32 per cubic yard of shingles, and each load
was very close to a cubic yard, so it cost me $64 to
dispose of the shingles. Disposing of shingles can be
expensive. Roofing contractors often get a "roll-off"
dumpster delivered to the job site. The same disposal
company charges an eye-popping $465 for their
smallest dumpster capable of handling the weight of
shingles (which in their case is a 10-yard roll-off
dumpster). So I took two trips to
the disposal station, which took less than an hour per
trip, and I saved four hundred bucks. That was time well
spent. Of course, I need a vehicle capable of towing the
loaded trailer, but even my wimpy 4-cylinder Dodge
Dakota can do that. I like using
a trailer because I can park it anywhere I want using my
trailer dolly... as long as I can move it when full, or
reach it with a truck. Of course
the cost savings I realized by using a trailer would
disappear as the volume of shingles increases. Hauling
ten cubic yards of shingles (that's 5 two-car
garages with single layers of roofing) in multiple
trailer trips would only save $145 in disposal costs.
Perhaps not worth the average contractor's time.
Estimating:
I'd estimate that a cubic yard
of 3-tab shingles weighs around 900 pounds when tightly
packed, and represents 380 to 400 square feet of roof
area with one layer of shingles. Three-tab
shingles usually weigh 225 pounds per square (100 square
feet). |
|
Next step:
Working With 3-Tab Shingles:
Installation Details For Professional Results.
More Info:
|
|
|
- Basic Carpentry Tools
- Shingle Scraper
- Pry Bar
- Nail Gun
- Hammer-Tacker (or Staple Gun)
- Rolling Magnet
- Tarps or Sheet Plastic
- Utility Trailer
- Ladders
|
Materials Used:
- 15# Felt (2 Rolls)
- Staples, 1/4" (2 Boxes)
- Roofing Nails
|
|
|
Related Articles:
|
Web Links:
|
|
|
|
|
|
|
|
|
|
|
|
