Type of roof material

Originally Posted By: gporter
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What is the name for a roof that has gravel or small pebbles


Originally Posted By: psisler
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Gary,


This type of roofing is called BUR or (built up roofing). After the sheathing in laid down there are applications of roofing felt (sometimes several layers) then an application of bitimen and then a layer(s) of asphalt, coal tar, or lap cement. Then the gravel or pebbles or what ever is spread over the surface. There can be ASBESTOS in some of the coatings though. These type roofs have been around for quite a while and if properly applied could last as long as 50 years depending on weather conditions etc. Hope this helps.

Patrick


Originally Posted By: gporter
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Outstanding Pat. Thanks.


Originally Posted By: rcooke
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Great roof last a long time . They too have suffered with E&O insurance problems and not many wish to do it any more in Canada . The reason is hot tar and it can catch on fire very easy and burn hot and fast , A good site with info is http://www.metroroofing.ca/landing.htm


Roy sr.


Originally Posted By: rmeyers
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Gary,


The gravel or pebbles are actually a ballast to help hold the system in place from the effects of "wind lift". The base sheets were generally spot mopped to the roof plywood or solid mopped over insulation board. Nailing was not standard for the felts unless the slope required back-nailing to hold the sheets in place for installation.

These systems were very heavy, with standard specifications often using 300lbs of slag or 400lbs of gravel or 500lbs of white marble chips per square for the surface. (In addition to the varying layers of felt and tar.)

The stones also helped protect the tar surface from weathering. (White chips reflecting heat etc.)

The systems were great while they lasted but when problems started, they were hard to maintain because leaks were often difficult to track down and generally costly to repair properly.

Today's adhered or mechanically fastened single membrane systems have now replaced many of these systems and is the system of choice for most designers when working with "flat" roofs. These modern systems have also made our job as inspectors easier in tracking down roof leaks.(Usually at flashing details.)

Just a few more rambling comments from an old contractor turned inspector!

HAVE A GREAT DAY!!! ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif) ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif) ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)


Originally Posted By: psisler
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Gary,


You are welcome!

Russell is right in many areas. Today, however, Bitumen is used in almost a single layer that is sealed with heat, usually a propane torch that seals all of the seams and the surround and a light mop (either cold or hot) is added for the topping. The toppings nowadays is usually just for looks and has no ballast what-so-ever. Years ago it was truly a ballast but not anymore, strictly ambiance. The seals, if done correctly will not leak for a very long time. Just my HO.

Patrick