Howdy - I'm looking for some info/advice on our tar and gravel roof.
I'm not too savvy with roof stuff, so bear with me if I don't describe
things properly or miss out on some info.

We've been in this house about a year, it's about a 27-year old house,
on the Northern California coast (rain and fog, no freezing). The
garage and two rooms of the house are under a tar-and-gravel roof. It
may be the original roof, we don't know.

First thing I noticed was water pooling on the driveway, coming under
the garage door. Looking up, I see that it's coming over the top of
the roof, above the garage - but specifically, it's coming through
about one inch below the edge, where some trim meets the outer walls
of the front of the house.

We had a couple of roofing people look at it - the usual range of
"replace the whole thing" to "too small for me, just patch it
yourself." So I decided to try it myself, based on some suggestions
for how to approach patching the edges.

First thing I notice is that there are some big puddles. I've been up
a few different times and we've always got bigger puddles than our
neighbors, for longer. The roof is not flat or pitched properly for
drainage.

I've got a bunch of questions - any help with any of them is
appreciated!

* The only thing I've found about fixing some of these lower spots is
http://doityourself.com/roofing/roofstandingwater.htm - basically
putting down increasingly larger concentric circles of roofing
material to raise it up on the low spots. Any thoughts on this
approach? 1 - Does it have to be dry to do put this stuff down? and 2
- the gravel is loose on top but much of it is embedded in the tar -
so how low do I need to "scrape" before putting any new material on?

* what are some methods for removing the water? I tried sweeping some
directly into the gutter downspout, but that takes a LONG time with
very little effect and doesn't work for all the puddles given where
the puddles are and where the downspouts are?

* as far as the "leakage" along the front edge, I was advised to patch
the edge of the roof - I'm not sure how to describe this - but
whatever is joining the roof material to the edge - I can see sort of
a crack where it opened up. I scraped (using a wirebrush) whatever
loose gravel I could get, and took some Plastic Roof Cement (wet or
dry surfaces) and applied it. It seems to be mostly working, but it
also doesn't seem to harden. Is it supposed to, the way caulking does?
It's pretty tough to apply because it sticks to itself more than it'll
stick to a wet roof....


Thanks - a lot of intertwining issues here, appreciate any help!

Subject: tar-and-gravel roof - puddles etc. advice needed
From: (Steve Portigal)
Date: 11/17/04 5:03 PM Pacific Standard Time
Message-id:

Howdy - I'm looking for some info/advice on our tar and gravel roof.
I'm not too savvy with roof stuff, so bear with me if I don't describe
things properly or miss out on some info.

We've been in this house about a year, it's about a 27-year old house,
on the Northern California coast (rain and fog, no freezing). The
garage and two rooms of the house are under a tar-and-gravel roof. It
may be the original roof, we don't know.

First thing I noticed was water pooling on the driveway, coming under
the garage door. Looking up, I see that it's coming over the top of
the roof, above the garage - but specifically, it's coming through
about one inch below the edge, where some trim meets the outer walls
of the front of the house.

We had a couple of roofing people look at it - the usual range of
"replace the whole thing" to "too small for me, just patch it
yourself." So I decided to try it myself, based on some suggestions
for how to approach patching the edges.

First thing I notice is that there are some big puddles. I've been up
a few different times and we've always got bigger puddles than our
neighbors, for longer. The roof is not flat or pitched properly for
drainage.



There shouldn't be any puddles. What is the cause of the puddling? Are any of
the joists sagging? cracked? If so, I would jack up problem joists & "sister"
(glue & staple or nail) either plywood or another joist to the offending ones.
try to obtain a roof slope that leads to better drainage.

I've got a bunch of questions - any help with any of them is
appreciated!

* The only thing I've found about fixing some of these lower spots is
http://doityourself.com/roofing/roofstandingwater.htm - basically
putting down increasingly larger concentric circles of roofing
material to raise it up on the low spots. Any thoughts on this
approach?

this can work but you're adding more weight to a system that already sags? How
deep are the puddles? More than an inch?

1 - Does it have to be dry to do put this stuff down?

No, not if you use produces that are specifically formulated for wet
application. In a pinch I use "wet patch" but in SoCal I can usually wait for
the roof to dry or use a roofing torch to speed things up. I usually fix a dry
roof with "non wet surface" products.

and 2
- the gravel is loose on top but much of it is embedded in the tar -
so how low do I need to "scrape" before putting any new material on?


Read the directions; they typically want loose & dirty material gone. Think of
it as a rather crude paint job. Paint doesn't work very well on loose material
or over dirt/dust. I usually sweep, hose off, let dry.


what are some methods for removing the water? I tried sweeping some
directly into the gutter downspout, but that takes a LONG time with
very little effect and doesn't work for all the puddles given where
the puddles are and where the downspouts are?


wet/dry vac; vacuum up water & dump overboard


* as far as the "leakage" along the front edge, I was advised to patch
the edge of the roof - I'm not sure how to describe this - but
whatever is joining the roof material to the edge - I can see sort of
a crack where it opened up. I scraped (using a wirebrush) whatever
loose gravel I could get, and took some Plastic Roof Cement (wet or
dry surfaces) and applied it.

You did the right thing here.

It seems to be mostly working, but it
also doesn't seem to harden. Is it supposed to, the way caulking does?

It will eventually harden: the stuff is solvent based & takes a while for the
solvent to leave.

It's pretty tough to apply because it sticks to itself more than it'll
stick to a wet roof....

yes it is, I use the two knife system. A smaller (maybe 2 to 3" knife) & a
larger 6 to 8" knife. Take it out of the can with the small one & put it on
the big one. Use the big one as a pallet & apply with the small one. Where
appropriate you can smooth with the big one & touch-up / clean-up with the
smaller one.

I also use the asphalted fiber tape (~6" wide come is a roll) wrorks good fro
bridging cracks. When I'm done with the knife work I usually slather on a
layer of lap cement (the loose stuff, goes on with a long handled roofing
brush) to seal everything up. I only have a very small flat roof area; about 5'
x 20'

You're doing good, soon you'll be an expert. I learned the hard way too, one
my 80 year old garage that has a tiny flat section. It needs attention every
year or so. I've owed the house for about 25 years & have still managed to
avoid really fixing the flat roof problem. IMO you're doing the best you can
do short of replacing the roof & doing it correctly.

good luck
Bob

First thing I notice is that there are some big puddles. I've been up
a few different times and we've always got bigger puddles than our
neighbors, for longer. The roof is not flat or pitched properly for
drainage.

Puddles are bad especially if they are extensive or several inches deep. In
your area they may leak thru before they evaporate, due to wet conditions
there. Roofs are not meant to resist hydraulic pressure. May indicate rotted
or warped support rafters or plywood. You need to look under the puddle
areas, from the inside of the house. What causes the sagging. Fixing this is
important. A qualified carpenter might have some idea of what happened.
Most roofers want a quick sale, and could care less what causes sags. Many
will reroof, ignoring the sags, so you just have new puddles.

* The only thing I've found about fixing some of these lower spots is
http://doityourself.com/roofing/roofstandingwater.htm - basically
putting down increasingly larger concentric circles of roofing
material to raise it up on the low spots. Any thoughts on this
approach? 1 -

Bad approach, could overload roof. Definitely a temporary, and not very
good, fix, as those areas may continue to sag....

* what are some methods for removing the water? I tried sweeping some
directly into the gutter downspout, but that takes a LONG time with
very little effect and doesn't work for all the puddles given where
the puddles are and where the downspouts are?

Use a garden hose and siphon it off, if you don't have a vac. A gas powered
leaf blower could finish the job. Fill the garden hose with water, cap both
ends, weight down puddle end, remove cap, then remove lower cap, where it
dangles over the roof, below the water line. Suction will do the rest.

* as far as the "leakage" along the front edge, I was advised to patch
the edge of the roof - I'm not sure how to describe this - but
whatever is joining the roof material to the edge - I can see sort of
a crack where it opened up. I scraped (using a wirebrush) whatever
loose gravel I could get, and took some Plastic Roof Cement (wet or
dry surfaces) and applied it. It seems to be mostly working, but it
also doesn't seem to harden. Is it supposed to, the way caulking does?
It's pretty tough to apply because it sticks to itself more than it'll
stick to a wet roof....

This is a good first move. Henry's what I use, stays flexible and slightly
wet for a long time. That is what helps it seal, and resist leaking again.

* what are some methods for removing the water? I tried sweeping some
directly into the gutter downspout, but that takes a LONG time with
very little effect and doesn't work for all the puddles given where
the puddles are and where the downspouts are?

Been there, done that. Get one or more sump pumps, discharge hose(s)
through downspout. Be watchful that the hoses don't eventually start to
compress where they bend, though. Some can run with minimal water depth;
the ones that have an "automatic on" water sensing feature tend to need
more water depth in order for the float to trigger the operation, so I
found that the cheaper "no float" ones worked better in the long run.
For this reason Home Depot's variety didn't work as well as the "Ace" brand.

Does your house have excessive humidity (e.g. windows fog, condensation
on sills)? if so, the roof is undoubtedly in bad shape, letting in
excess moisture in addition to any obvious water leakage.

Good luck.

There shouldn't be any puddles. What is the cause of the puddling? Are any of
the joists sagging? cracked? If so, I would jack up problem joists & "sister"
(glue & staple or nail) either plywood or another joist to the offending ones.
try to obtain a roof slope that leads to better drainage.

I don't know the cause of the puddling! The roof just doesn't appear
to have any proper grading to it - there are sections that are lower
than others. How can one tell about the joists? There is nothing
obviously sagging etc.

There's nothing from inside the house that is amiss in any way.

[thanks for the help on the other stuff - very useful]

[good sump pump advice snipped - thanks]

Does your house have excessive humidity (e.g. windows fog, condensation
on sills)? if so, the roof is undoubtedly in bad shape, letting in
excess moisture in addition to any obvious water leakage.

No, everything inside is fine. No moisture, no leaking, no marks on the ceiling.

Just puddles on the roof!

Puddles are bad especially if they are extensive or several inches deep. In
your area they may leak thru before they evaporate, due to wet conditions
there. Roofs are not meant to resist hydraulic pressure. May indicate rotted
or warped support rafters or plywood. You need to look under the puddle
areas, from the inside of the house. What causes the sagging. Fixing this is
important. A qualified carpenter might have some idea of what happened.
Most roofers want a quick sale, and could care less what causes sags. Many
will reroof, ignoring the sags, so you just have new puddles.

The puddles have finally evaporated, but were about two inches at the
deepest and covered a good portion of the roof.

From the inside of the house, however, everything is fine. No signs of
anything amiss - the ceilings inside are level.

I'm a bit puzzled as to how to proceed and would like to avoid simply
replacing the roof - your point that a replacement may not even fix
the problem is a bit alarming!


[Thanks for the help on the other issues as well]