Leak Chasing 101

             Leak Chasing 101
Finding the leak is half the battle. Roof leaks
are usually not difficult to repair… But finding them
can be tricky. The main problem is: The place the
leak is showing up inside, may not be directly
under where it’s coming in outside.
For example, on a sloped roof, the water might get
under the roofing at a protruding nail, and then run
between the roofing and the plywood deck until it
gets to a seam in the plywood. Then it drips onto
the top side of a cathedral ceiling where it runs
down to a seam in the drywall. The spot it’s getting
through the roofing can easily be several feet away
from the spot it’s showing up inside.
Drips can also get diverted by rafters and stuff they
land on in the attic. I chased one leak that rode an
air conditioning duct for twenty feet from the spot it
came in.
Analyzing leak signs in the house. The first
step in finding a leak is to check out where it is
showing up in the house (assuming it’s not just
leaking outside through a soffit).
What you see inside can tell you a lot. It can tell
you if you’re looking for a big leak, or a small one.
A tiny stain on the ceiling indicates one thing. A big
hunk of drywall lying on the floor indicates a lot
more water coming in.
If the stain is still wet, you know it’s an active leak.
If not, it might be from an old roof repair, but the
ceiling was never fixed. Or perhaps the old stain is
bleeding through the new paint.
The most important thing you learn is EXACTLY
where it is showing up inside the house. The roof
problem may not be directly over the spot, but
that’s the best place to start looking. Here’s how to
transfer the location from inside the room to the
roof.
• Measure the exact distance from the leak to a
"reference point" you can see both inside and
outside the house. Windows and exterior doors
make great reference points. Draw a little sketch,
showing the distance between the leak and your
reference point
• When you are back outside, place your ladder
right by the reference point, IF that’s a safe place
for it. (See the section in Chapter Seven on ladder
safety) If that’s not a good spot for your ladder, just
toss a little pebble on the roof directly over the
reference point, to get you orientated up on the
roof.
• Note the width of the soffit overhang on your
sketch.
• Also, remember that your measurements
inside the room are horizontal and the ones on the
roof will be along a sloped plane (unless the roof is
flat). You need to allow a little for this difference.
On a roof with a 5:12 slope, add 8.3% to the
horizontal measurement. That comes out to an
extra foot along the slope for every 12 feet
horizontally. Add a little more for steeper slopes, a
little less for those with a lower slope.
This may allow you to find the roof problem without
ever going in the attic. That is especially helpful
when you have little or no attic access. It is also
helpful when you are not athletic enough to crawl
around attics. That’s a condition I found myself in
recently while recovering from some broken
bones.
Finding leaks without going in the attic can be a
little more challenging, but entirely doable. Like
most things, it gets easier with experience. www.macgregorroofing.com
Following the water path through the attic. Still,
finding a roof leak is somewhat simplified if you
have good attic access… and you’re up to the
task. You can see where the water is dripping
through the roof sheathing and if it is being
diverted. This is how to proceed…
• Gather up a flashlight, a bucket, a tape
measure, a hammer, a couple long nails, a short
board (two to three feet will do), writing paper and
a pencil or permanent marker.
• Go on up in the attic but watch where you step
(or crawl). You could easily break through the
ceiling. KEEP YOUR WEIGHT ON THE
FRAMING!
• Get directly over the wet spot. A helper can tap
on the ceiling with a broom handle if you're not
sure of the location.
• If the water is still dripping, get the bucket
under it. It’s better to catch the water in the attic
before it soaks into the insulation and ceiling. Set
the pail on your board, spanning two ceiling joists.
Don't set it right on the ceiling because the drywall
might not take the weight as the bucket fills up.
• Mark the spot on the underside of the roof
sheathing where the water is coming through.
• If the water has already stopped dripping, pull
the insulation back and set your flashlight on the
stain pointed straight up. Look for water marks on
the wood and mark the spot where they first show
up.
• Look for a reference point you can use when
you are up on the roof. This might be a plumbing
vent pipe going through the roof, a “goose-neck”
vent, a skylight or a chimney.
Measure from your reference point to the spot
where you first see the water coming through the
wood sheathing. This may not be the exact spot of
the actual leak, but it’s where to start looking when
you are up on the roof. Make a little sketch to keep
yourself orientated.
• If there are no good reference points to use,
you can make your own. After the rain has stopped
and you're ready to make the repair, go ahead and
drive a nail up through the roof at the exact spot
the water was coming through.
You might be reluctant to put a hole in your roof,
but this can be the best way to pinpoint a leak.
Using this method, I have found hidden leaks that
stumped other roofers.
Just don’t forget to patch the nail hole!
Pinpointing the problem on the roof. Using the
detective work you’ve done so far, you should be
able to get on the roof directly over the leak… or at
least where it's showing up inside. Now you need
to be very observant.
Starting at the spot you've pinpointed, do a very
thorough search of the area, particularly the
"uphill" side of the leak. You are looking for any
place at all where water could get through the
roofing.
Sometimes the problem is obvious, sometimes it’s
hidden. Keep looking. Be patient. The water has to
be getting in someplace.
Water-testing tips. Flooding the area with a water
hose MIGHT help you pinpoint the problem.
One big caution here; avoid walking on a wet
roof… especially if it is wood, tile or metal. Keep
your ladder off to the side -- away from the water
Start low at first. By that I mean, direct the water to
the lower parts of the roof. Let the water run on
each area for about fifteen minutes, before
directing the stream to a higher spot.
If there is a flashing detail in the area such as a
vent, plumbing pipe or valley, it might very well be
the problem. Directing water right on it will quickly
reveal if that’s the source of your leak.
It’s easier and safer to have a helper in the house
(or attic) monitoring the leak area while you are
water testing. Other wise, you will have to keep
running up and down the ladder.
Cell phones work good for coordinating your
efforts. Just don’t lose your phone in the attic
insulation. Yep, I’ve done that too!
After the repair, water-testing the same area
MIGHT tell you how effective your work was.
Just remember that water testing isn’t always
definitive. It’s tough to duplicate a torrential
blowing rain with a water hose. But if it still leaks www.macgregorroofing.com
when you water test it after the repair; you know
you still have a problem.
Six “head-scratchers” that might trick you. I
hate to throw technical jargon at you, but nothing
fits like the term us roofers use to describe a leak
that’s tough to find. We call it a “head-scratcher.”
An especially puzzling one is called a “REAL headscratcher.”
Back when I “knew it all” I would get irritated when
I couldn’t instantly find a roof leak. There’s a fine
line between confidence and arrogance… I
confess to having strayed over the border on
occasion. But as I’ve gotten a little older, I’ve
become more philosophical on the matter. I’m now
convinced that the very purpose of a “headscratcher” is to keep me humble!
Another thing I’ve learned over the years is that
leaks aren’t always caused by roof problems. Here
are some of the other things it might be:
1. Plumbing pipes. Leaks in water supply lines
can show up even when it's not raining. Typically,
a joint is dripping or there’s a little spray of water
coming out a pinhole in a pipe. Drain lines can also
leak. You find those under roof drains, plumbing
fixtures and hot tubs.
2. Air conditioners. Clogged condensate lines
are the main culprits.
I lost a 4’ x 4’ piece of the ceiling over my
daughter’s bedroom from this very thing. My wife,
Martha, saw the bulging drywall and thought it was
a bad roof leak. She told me I better come quickly
because it was going to collapse. But… I was
watching a good football game at the time. I
glanced out the window at the sunny day with no
rain in site, and told her I would get to it at half
time. About two minutes later I heard the crash
and she hasn’t let me forget it ever since. Some
day I’ll learn to LISTEN to that woman!
Another common leak problem with air
conditioners occur when the drip pan under the
condenser rusts out. One time I asked an AC tech
why they weren’t made from aluminum. He just
grinned and said “Why do you think?”
3. Windows and siding. These leaks show up
with torrential rains combined with strong winds.
4. Stucco cracks. Even small cracks suck water
like a sponge. The horizontal cracks are the worse.
And your sprinkler system might be supplying the
water when it’s not raining.
5. Chimney leaks. Leaky mortar joints might be
the problem. Or it might be an ill-fitting chimney
cap that is letting water in.
6. Planters. Some times these are mounted on
an exterior wall and leak inside, but it has nothing
to do with the roof .
macgregorroofing.com

5 basic roof repair methods.

Here are some basic methods for repairing roof
leaks. In most cases, only a small amount of
material is needed. In fact, $100 worth of material
can fix many leaks.
Caulking can be used for many roof repairs,
providing it is done right. Here are some tips:
1. Use a good grade of caulk. Painters latex caulk
isn’t a good choice for roofing, because it won’t
last long. For a little more money, you can get
polyurethane sealant, which is a good choice for
many roofing applications.
2. To get a good bond, make sure the area to be
caulked is CLEAN AND DRY.
3. Don't just run a bead with a caulking gun. Work
the caulk into the joint. I haven’t found anything
that works as well as my finger for this.
“Three-coursing” is a quick and easy method to
stop almost any leak. When applied properly it is
compatible with just about any roof system. This is
how to do it right.
• Make sure the area is clean and dry.
• Spread a THIN layer of flashing cement over
the hole or crack and work it in to the
underlayment. Be sure to use flashing cement that
is compatible with the roof system you are
repairing.
• Test the adhesion by “patting” the cement with
your trowel. If you pat the cement and it comes up
with your trowel, the surface is too wet or too
dusty.
• Lay roofing membrane in the flashing cement
and work it in with your trowel. I like the strong
fiberglass type of membrane that comes in 4” wide
rolls. Unlike cotton membrane, you can’t rip it. You
have to cut it with scissors or a sharp knife.
• Spread another layer of flashing cement over
the membrane. Put just enough on so the fabric
mesh is not visible.
• For a final touch, the repair can be finished off
with roofing granules (applied when the cement is
fresh) or roof coating (applied after the cement has
set up).
Roof Coatings serve some useful purposes that
are discussed in Chapter Six. But generally
speaking, they are designed more for leak
PREVENTION than for leak REPAIRS.
However, roof coatings do go hand-in-hand with
the “three-course” method just described.
Coating can improve the appearance of the repairs
and more importantly, it will extend it’s life by
minimizing solar degradation.
Both white and aluminum coatings are available
for this purpose. They come in one gallon and five
gallon pails and can be applied with either a paint
brush or roller.
Again, make sure the surface you are applying it to
is both clean and dry.
Mending Tape is a relatively new material that is
excellent for many types of repairs. There are
several types made in several sizes by several
manufacturers. A company that specializes in this
type of product can be found in the Resource
Section.
Mending tape has a self-adhering backside that
sticks like crazy to just about anything. The
material is also flexible, so it can move with the
roofing as it expands and contracts.
And the top surface is white or silver to reflect
damaging UV rays.
Once again, make sure the roof surface is clean
and dry before installing the tape.
The stuff is “pressure sensitive” which means the
effectiveness of the bond depends on the amount
of force applied when installing it. A steel roller
helps you exert a strong, consistent pressure over
the entire patch.
Just replace it. When the roofing is damaged so
badly it can’t be repaired, it must be replaced. I’m
not talking about the whole roof, just the damaged
parts.
This is where that bundle of material leftover from
your reroofing project comes in handy. It’s the right
size, the right color and is available for “free” right
in your garage. You don’t have to spend thousands!
Macgregorroofing.commacgregorroofing.com

How to Ensure All Your Roofing Bids Are Specified Correctly

How to Ensure All Your Roofing Bids Are Specified Correctly

Before you solicit your first bid, you need to
determine the scope of work. If you don’t do this,
the proposals you get from prospective roofers
may be very different from each other. You will be
trying to compare “apples to oranges”.
The problem is: Most people don’t know enough
about roofing to write good specifications. If you
do… great! If not, here are some other ways you
can come up with a good spec:
• If the scope of the project is large enough to
justify the expense, a roof consultant could
establish the scope of work. He (they’re usually www.macgregorroofing.com                                        Roofing Contractors                                
men, but not always) can also help select bidders,
oversee the project and inspect the work to make
sure you’re getting what you paid for.
• Most roofing manufacturers have specs written
for their products. Of course they specify their own
components wherever possible, but that is not
necessarily a bad thing. Extended warranties are
available from these companies when you use
their “system”.  These specs are often available
right on their websites, which you can find in the
resource section at the back of this guide.
• Another way to get a scope of work is to get
your first bid from the most solid roofer you can
find, and then make a copy of his specs for each of
the other bidders. Be sure to remove the name of
the original company and his price from the specs.
The other bidders may want to use their own spec,
but explain what you’re doing and ask them to use
your spec, so you can compare “apples to apples”.
If they want to present their own spec as an
alternative for your consideration, that’s fine.
Although you might not get the ideal spec with this
method, at least everybody will be bidding the
same way.
To give you an idea of what a good residential
spec looks like, here is one I’ve used a lot. It’s for a
complete reroof down to the bare wood, and
includes both steep-sloped and low-sloped roof
sections. It also includes clauses that are fair and
reasonable to both the homeowner and the
contractor.
======================================
For the “Steep-sloped” areas…
• Remove the old existing roof down to the bare
wood deck.
• Repair any deteriorated wood and re-nail
sheathing as required to meet current building
codes. (See Note # 9)
• Furnish and install Titanium UDL
Underlayment
• Furnish and install new .025 pre-painted
aluminum drip edge.
• Furnish and install new mill finish .025
aluminum valley metal.
• Furnish and install new lead flashings at the
plumbing vent pipes.
• Furnish and install new mill finish aluminum
“goose-neck” vents.
• Furnish and install GAF-ELK “Timberline” 30-
Year, fungus-resistant, fiberglass architectural
shingles with six nails per field shingle and four
nails per cap shingle.
• Furnish and install ___ feet of new pre-painted
aluminum ridge vent
For the “Low-Sloped” areas…
• Remove the old existing roof down to the bare
wood deck.
• Repair any deteriorated wood and re-nail
sheathing as required to meet current building
codes. (See Note # 9)
• Furnish and install tapered system to provide
positive drainage.
• Furnish and install Certainteed Base Sheet.
• Furnish and install Certainteed Self-adhering
Mid-Ply (smooth-surfaced modified bitumen).
• Furnish and install new .025 prepainted
aluminum drip edge.
• Furnish and install Certainteed Self-adhering
Cap Sheet (white granular-surfaced modified
bitumen).
Please note…
1. All material is guaranteed to be exactly as
specified (or equivalent if not available).
2. All work to be completed in a workman-like
manner and meet or exceed all applicable
building codes.
3. All workers to be fully covered by workers
compensation and liability insurance as
required by law.  Roofing contractor to provide
copies of insurance certificates prior to
commencement of work. www.macgregorroofing.com                                      Roofing Contractors                                   50
4. This agreement is contingent on items beyond
our control such as weather, accidents and
material delays.
5. Water intrusion due to leaks within a roofing
system can lead to the proliferation of mold on
exterior and interior surfaces.  In performing
this work, it is understood and agreed that the
roofing contractor and their insurance carrier
disclaim liability for any mold problems and will
not be held responsible for any direct,
incidental or consequential damages, including
health problems attributable to past, present or
future water intrusion and associated mold,
fungus, mildew, or algae growth.
6. Any legal claims relating to this agreement
shall be settled by arbitration in accordance
with the American Arbitration Association.
7. This proposal excludes any interior repairs,
painting, gutters, soffits, fascia, pool cages and
solar removal and replacement.
8. Any alteration or deviation from the above
specifications involving extra costs will be
executed only upon written orders, and will
become an extra charge over and above the
estimate.  
9. Since deck problems are a hidden condition
until the old roofing is removed, any work
needed to repair it is in addition to the price
quoted below. We charge $37 per man-hour,
plus materials (including sales tax and 15%
mark up) for this work.  Roofing contractor to
provide before and after photos of all wood
repairs. Alternately, we would be pleased to
work with any carpenter that you might
provide.
10. This proposal includes clean up and removal of
all roofing debris. It also includes all permits,
inspections and filing of the “Notice of
Commencement” at the county clerk’s office as
required by law.
======================================
The proposal should also specify the warranty, the
price for the work, and when the payments are
due.
Keep in mind though, that roofers in different parts
of the country do things a little differently. In snow
country for example, it is common to run a selfadhering waterproof membrane along the eaves to
help protect the edge of the roof from water
trapped by ice dams in the gutters.
Once you have a scope of work, the next step is
choosing your roofing contractor.  Good luck in your search!
macgregorroofing.com

Where to find the most reputable roofer in town.

Start a file on prospective roofers. Stick with 

professional roofing contractors. In most areas that 

means they are accountable to a local or state 

licensing board. That gives you some leverage if 

you need it. “Roofers from Hell” don’t worry about 

licenses, permits or their responsibilities to you. 

Ask your friends, neighbors, relatives and 

coworkers if they can recommend someone. They 

might also tell you who to avoid! 

  

Call the roofing suppliers in your area or drop by 

for some product literature. Talk to the manager, 

tell him about your project and ask for the names 

of a few good roofers. If nothing else, he knows 

who pays their bills and who doesn’t, which is part 

of being professional. 

Call the building inspector’s office for your 

municipality and speak to a roofing inspector. Ask 

about the permit and inspection requirements for 

your project. While you have him on the phone, 

ask for a few names of roofers in your area who do 

good work. He probably won’t make an official 

endorsement, but he might give you a few names 

to check out. 

I don’t recommend getting bids from everybody in 

the phone book, but your roofer should be listed 

there if they’ve been in business longer than a 

year or so. A phone listing is just part of being 

professional, so prospects and customers can find 

you.  

But don’t be overly impressed by the big ads you 

see in the yellow pages. They’re very expensive 

and may be an indication the company depends 

on them for leads rather than referrals from 

satisfied customers. www.macgregorroofing.com                                        Roofing Contractors                             

Pay attention to roofing work going on in your 

neighborhood. Look for yard signs and company 

names on the vehicles.  

What’s the condition of their trucks? If they don’t 

care about their own equipment, how much do you 

think they will care about your roof?   

What about the roofing crews? Do they go about 

their work in a quiet professional manner… or 

does the jobsite resemble a wild roof party, 

complete with beer and music blasting from a 

boom box?  

Do they keep the jobsite clean… or are there 

shingle wrappers and debris blowing all over the 

neighborhood?  

If you get the chance, talk to the homeowner after 

a hard rain… is he a happy camper? 

Finally, check out your prospective roofers on the 

internet. Google the names of the companies and 

also the owners.  

See what Angies List (www.angieslist.com) and 

the Better Business Bureau (www.bbb.org) have 

on them. Also check their status with your local 

and state licensing boards. 

By now you should have several companies to 

choose from. Select the three with the strongest 

reputation. 

Call each of the three you have selected and 

request an estimate. Make an appointment with 

each of them… at least two hours apart. They 

expect you will get other bids, but they don’t like to 

run into their competition on your roof. It gives the 

impression you are calling everybody in the phone 

book and going with the cheapest price. 

The good guys will go the extra mile for you, but if 

they think all you are interested in is the cheapest 

price, they probably won’t be very interested in you 

or your project. 

When each roofer shows up, make note if he’s on 

time. This is a clue to his character and business 

savvy. If he can’t even be on time when he’s trying 

to get your business, how responsible will he be 

after he gets it? Anybody can be late, but he 

should at least call. 

You should try to establish some rapport with each 

roofer. Keep in mind that while you are sizing him 

up as a potential contractor, he is sizing you up as 

a potential client. He’s trying to separate the 

“prospects” from the “suspects”. 

He wants a client who is friendly, decisive, 

reasonable, non-obtrusive, and one who will allow 

him a fair profit. The good guys usually have plenty 

of work. They can afford to pass on people and 

projects that are problematic. 

The impression you want to give this guy is that 

you are friendly, but also an informed consumer 

who is serious about getting a good job. 

Give the estimator your spec sheet and ask him to 

bid it this way. If he wants to do it different, get his 

reasoning and ask him to bid his way as an 

alternative. 

Some roofing contractors estimate their own jobs; 

some have a salesman do it. Some do it in one 

trip, some measure the roof up and come back 

with a presentation. Any of these methods is 

acceptable. 

Once the roofing proposal is prepared, it would be 

good to sit down with the roofer to discuss it. You 

might offer him a soda or coffee. Ask questions 

and listen carefully to the answers.  

One important question to ask is: “Exactly why you 

should hire HIM rather than his competitor”. If he 

doesn’t have a good reason for that, maybe there 

isn’t one.   

If you have a salesman pushing you to sign, just 

tell him you are getting two other bids and you 

can’t possibly make a decision until you have all 

the information. 

At this point, you should have a bid from each of 

three roofers for identical scopes of work. Review 

the information you have on each roofer. Call them 

back if you need a clarification. Compare the 

prices, terms and warranties.  

As you make a decision, pay close attention to 

your “gut feeling”. This is really just your 

subconscious picking up little clues that you 

weren’t consciously aware of. It might be his body 

language, his handshake or something in the way 

he makes eye contact.  

It doesn’t really matter what it is. But something is 

telling you that you can trust this guy or you better 

not trust that one. Listen to these feelings as they 

are surprisingly accurate.  

If you are leaning towards a particular roofer and 

he is the lowest price of your three candidates you 

have an easy choice. 

If your first choice is higher than the others, you 

have a decision to make. You could try to get him 

to lower his price. Just call him and say that you 

really want him to do the job, but his price was “X” 

dollars higher than his competitor. He may be 

willing to match that price, or come down some to 

get the job. 

On the other hand, you may want to give him his 

price. Some roofers get offended when you try to 

beat them down and any rapport you’ve built with 

them will be shot.  

If this is the guy you will probably hire anyway, you 

want his best efforts… rather than something less 

because you’re paying him something less than 

his price. 

If you decide to pay his price even though he is a 

little higher than the others, be sure to mention it. 

He will appreciate your trust and possibly try extra 

hard not to disappoint you. 

Once you’ve decided who you want, you are in a 

good position to encourage the roofer to “sweeten 

the deal” a little. 

For example, say you want to get the work done 

fast.  Call the roofer and ask him if he could start 

right away if you gave him the job. He might be 

willing to juggle his schedule a little to get the 

work. 

If getting the best job is your hot button, call the 

roofer and ask if you could get his best crew if you 

gave him the job. Again he might be willing to 

juggle things around so you get his best guys and 

it didn’t cost you an extra dime to get them. 

My point is: If there is something else you want, try 

to award the job contingent on you getting it. 

That’s when you have the most leverage. 

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