Pitch and gravel roof?
The initial advice would still be,
"If it ain't broke . . . "
Your best answer would be from a local roofer.
Your existing roof may be a coal tar pitch roof which, if applied
correctly, is self healing. Most roofers do not like to work with
or around coal tar which will add to the cost.
He could give you the best advice about the following:
Spud back the existing ballast (gravel)
Apply a fresh 3 ply or 5 ply hot mopped roof or a flood coat of
hot.
He would have to advise you about coal tar pitch or bitumen.
Reapply ballast.
- OR-
Spud and remove existing ballast
Apply single layer modified bitumen roof over your existing roof.
It looks a bit like rolls of 90# roofing with the stoma granules
already on it. It is a very different product, you cannot tear it
or break it by bending.
Modified bitumen has become the method of choice for most flat
roof applications.
- OR -
The other choices would be EPDM (a glued down continuous rubber
sheet similar to an inner tube) and foam roofing with an
elastomeric seal.
If you need extra insulation, it can be added on top of your
existing roof with the new roof added on top with all methods.
Your contractor friend can advise you about the load carrying
ability of your existing roof framing. By removing the ballast,
the foam roof, the modified bitumen roof, and the EPDM have the
least change of weight to the framing.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing. . . .
DanG
"Terry" wrote in message
...
Would welcome any advice about our pitch and gravel roof.
A single storey bungalow roof, 72 feet by 37 feet, with a slope
of about
three feet in an 17/20 foot span. (The ridge is off centre).
Total area about 2700 sq feet. The low slope allows one to walk
on it
without difficulty. At the edges it's only about nine feet off
the ground;
all of which makes it easy to work on. The roof overhang is two
feet which
keeps the drips away from the house; no gutters, hate them and
feel they are
recipe for rot in edge of the roof? Seems to have worked too!
Only twice have we had to shovel snow off the roof; normally it
blows away
into the North Atlantic! Occasionally we get wind gusts to100
mph here.
The only downside is that the roof space (one couldn't bless it
with the
word 'attic') above the ceiling is less than three feet high;
difficult to
crawl through and somewhat full of blown in loose fill
insulation added
some 20 - 25 years ago.
Roof has the minimum number of apertures through it. One brick
18 inch by 36
inch chimney, with suitable flashing. One 3 inch pipe vent. One
2.5 inch
electrical supply mast (in end eave) and one small one inch pipe
with
weatherhead for antenna cable. All these are inspected and kept
caulked.
Very plain shed roof, no dormers, or intersection of sections of
roof etc.
Plain and simple.
We have had minimum to no trouble with the roof, but it is now
33 years old
in a climate probably best described as 'Maritime' (i.e.
probably like the
Maine or Scottish coasts.?).
The only trouble has been that in one two spots between the
aluminum
(aluminium) edge flashing and the built up layers of tar and
felt, with
gravel scattered over, a slight gap might develop probably due
to
freezing/thawing etc. Each time this has been treated promptly
by flowing
hot tar into any gaps and checking for rot in the wooden facia
board and/or
soffits. In some 30+ years I have only had to repair two small
spots of rot
in the facia board each a few inches long; one a corner over the
garage,
where some condensation must have occurred. Also have added
extra
ventilators and ensured adequate overall ventilation of the roof
space in
all seasons. There is no evidence of rot in the roof structure
(gang nailed
trusses on two foot centres) or the roof deck which is T*G
lumber nailed
down to the trusses.
We have lost some of the original gravel due to wind and snow
over the years
and there are one or two small spots where the felt is starting
to look
bare.
It seems the original roofing contractor did a good job; roof
performing as
well or better than anticipated. But due to it now being some 5
to 7 years
beyond what is often cited as the 'life' of almost any roof here
it's time
to at least have a look at it.
Spoke with a leading and well respected contractor here who gave
a
recommendation for a reliable roofing contractor; but also
advised "If it's
not broke why fix it!". That was two or three years ago.
So that's the pitch (pun intended)! I would really welcome
advice from
anyone about experience of this type of roof. Viewing its
condition I am
wondering if the best course is to have a roofing contractor
sweep the
gravel clear and apply an additional coat or two of hot roof tar
or some
other product and then spread gravel again? Maybe that will make
it last
another 15 years by which time I'll be heading towards 90!
Honestly, I don't think I'm deceiving myself when I say the roof
looks that
good. Point is it IS 33 years old. I'm prepared financially to
do something.
It isn't in bad shape.
Any advice please.
My cordial thanks in advance.
Terry.
PS. I apologize for cross posting; but in eastern Newfoundland
we are
located sort of halfway between the major areas of North America
and the UK
with weather conditions common to certain areas in both!
|