well yes, as I said I was a little concerned about the effects of burying copper pipes in cement, but as you correctly point out doyle, this is how it is normally been done for gas fires..
for everybody concerned, please read the following website.. proves to be a bit of an interesting read.. about 3/4 of the way down the page.
http://www.copper.org/copperhome/faq_page_2.html
or extracted as below:
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Would you please inform me of any negative effects regards to cement and copper piping. Could the cement cause leaks over time, and if so, how long does it generally take to see the effects?
In spite of numerous myths regarding the acceptability of copper in contact with concrete, it is completely acceptable to bury/embed both hard drawn and annealed copper water tube in concrete. Decades of satisfactory service experience with the use of copper tube for in-floor radiant heating systems, water distribution systems and snow melting systems attest to the compatibility of copper tube embedded, encased or in contact with concrete.
It is also acceptable to run a copper water tube through a concrete floor or wall, provided that allowance is made for the lateral thermal expansion and movement of the tube and protection of the tube from abrasion. This can be done by insulating the tube where it passes through the wall or by wrapping the tube with an approved tape (to avoid abrasion) and installing it through a sleeve. Please refer to your local plumbing code for specific requirements regarding the protection of pipes and tubes passing through concrete and masonry floors and walls.
Both of the protection methods outlined above and the requirements listed in most plumbing codes are simply to protect the copper tube from the fatigue and wear caused by thermal expansion and movement. These protective measures are in no way dictated by the interaction of the concrete and the copper tube.
Also, the interaction of copper with either dry and wet concrete should not cause a corrosion concern. However, copper should be protected when it comes in contact with concrete mixtures that contain components high in sulfur, such as cinders and fly-ash, which can create an acid that is highly corrosive to most metals including copper.
One of the most prevalent myths regarding the use of copper in concrete is that lime in the concrete will have a negative or corrosive effect on the surface of the copper. In fact, a screened soil/pulverized limestone mixture is actually recommended as a selective backfill for copper tube to help eliminate corrosion concerns. There should be no concern regarding the interaction of the copper with lime in the concrete.
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Out of curiosity guys, with the advances of technology, is it now deemed more appropiate or required as part of Building Regs or something similiar, to have this special 'yellow plastic pipe' where running gas buried in concrete nowadays?
