copper pipe in masonry wall

[geothrm]

My house is made of cinderblock and concrete. I need hot water in my utility room.

I want to run 1/2 copper pipe from under my kitchen sink, thru the wall to the outside, along the outside wall to the back of the utility room, and thru the wall again. The outside run is about 18 feet long.

A friend told me that I can use a circular saw with a masonry blade to cut a trench for the outside run. Then lay the pipe in the trench, and refill the trench.

Does this sound feasible? What size saw do I need? Any special masonry blade? What should I use to refill the trench: concrete, mortar?

So, I think I know how to do this, I just don't know the specifics. If I could get some assurance, before getting started, that I won't ruin my saw, or (worse) my house, that would be greatly appreciated.

Geo.

[master plumber mark]

I dont know what it will do to your saw blade. or how many
saw blades you will chew up....maybe you ought to rent a saw..

I know it would be wise to put the copper pipe in
some sort of protective sleeve through the wall and
in the trench .before you cover it up...

the black armaflex covering works best..

[geothrm]

Thanks Mark. I guess this is not really a plumbing question, so I'll switch to a masonry forum. But thanks for the tip on insulation, which I wouldn't have thought of.

Geo.

[frenchie]

Always wrap copper in insulation (compressible foam type sleeves are typical) where it contacts masonry. The pipe needs some play for expansion & contraction without rubbing against the masonry.

I'm going to assume you're somewhere warm enough for pipe freezing not to be an issue...

[geothrm]

Yes, actually in Puerto Rico. I'm guessing the temp swing is rarely any greater than 60-95. May be enough to cause damage over the years?

[frenchie]

The pipes will still move from hot/cold water going through them, so you still need to sleeve them in something compressible.

You might have a harder time finding the foam insulation sleeves I was talking about, down there, than up here, though!

... just wrap the pipe in something that will create some space around it when you re-pack the trench.

[geothrm]

OK, thanks frenchie.

[daz49]

you may want to find out what the chemicals in the concrete will do to the copper overtime

[geothrm]

It appears there are no chemical reactions between copper and concrete that would prevent this.

[Terry]

Copper and concrete are always a bad combination.

Code here requires that the copper be protected from the concrete.

[geothrm]

And the insulation should take care of that.

[SewerRatz]

This is what I use for any pipe that is getting encased in concrete or buried underground. http://www.northtowncompany.com/polyc.html