Copper pipe through foundation

[Kevin C]

I'm just getting ready to connect the water feed lines for the garage to the house. That means bringing two lines through the foundation wall.

My question is should I sleeve the copper or not? I read a report that indicates that corrosion is not a problem, the copper can be in direct contact with concrete. I did buy heavy wall copper.

I was thinking of adding a thermal break on the hot water, but at the same time I'm not crazy about taking more concrete out. The lines are in a foam sleeve all the way to the shop.

The largest drill I could find for my deluxe Harbor Freight SSD drill hammer was 1". The 3/4" copper pipe just slides in the hole. I used a chisel to open the hole up a couple of inches in so I can pack it with hydraulic cement.

For the rest of the hole depth through the wall, I could just about fit a layer of heat shrink over the copper. I was thinking as long as I used some urethane adhesive to seal the heat shrink it should be fine.

Mostly, I dont want to open the hole up the entire 8" through the wall.

From what I read, code only requires a sleeve on new construction.

I'm bringing copper six inches away from the wall and connecting to the pex outside the foundation. That seems to be the norm.

My water line coming in is PEX and the plumber connected just outside the foundation. However, he made a pretty large hole in the wall and put a 2" OD thin walled sleeve in the wall to bring the pipe through . Both were then packed with hydraulic cement (the sleeve is still packed with cement, so the copper is still going through cement. Not sure i see the advantage)

I'm thinking i can do a bit neater job than that.

Comments and suggestions?

Thanks,

Kevin

 

[Big Bad Dad]

Code requirements apply to any new work, even in an existing house.

 

[Kevin C]

Code requirements apply to any new work, even in an existing house.

Following code is always good advise.

My reference was that it seems that the code is differant when your doing a retrofit.

Sleeves make a lot of sense when you are pouring a footing or a wall.

I'm not as sure they make as much sense when you are modifying an existing wall. Again, from what I read, the requirements (aka code) are differant when its new work to an existing structure.

I did find this in the Oregon plumbing specialty code: "313.10.1: Sleeves shall be provided to protect piping through concrete and masonry walls and concrete floors.

Exception: Sleeves shall not be required where openings are drilled or bored."

So it's OK to just send my copper pipe out through bored hole in the wall and seal it up. Just looking for the best approach and what has worked for others.

 

[coolreed]

I would run the copper through a lPVC pipe for protection. The only problem with copper is that sharp rocks in a foundation can cause penetration over time.

Copper kills bacteria naturally and is the way to go for a water supply.

 

[FluxCore]

Never required for bored holes. The sleeve prevents corrosion of copper from chemicals in poured concrete, plus allows a little 'slip' between pipe and slab.

But as good practice and to prevent entry of insects, moisture and as insulation, you should seal the entry around the pipe.

 

[plumbstupid]

Do it right the first time and run it through a sleeve. I fix several water lines every year that are leaking in the wall because they were not properly sleeved.

 

[surpdlr]

For what it's worth, I grew up in an early 1950's built house with radiant heat (copper pipe direct in concrete slab). By 1971, there were multiple leaks due to corrosion!!! All the house's in that area had the same problem!

I vote for keeping corrosive concrete away from copper!!

Good luck,

Jeff

 

[AZ Pete]

I believe that any pipe will move a little as it heats and cools, as well as when there are pressure changes within the pipe. In the long term, if the pipe is in contact with anything that is abrasive, you may well grind a hole in the pipe. Sleeve it, and save yourself some hassle in the future.

 

[Kevin C]

Thanks for all the input.

http://www.copper.org/applications/plumbing/techcorner/prevent_corrosion_cu_tube_buried.html

I did a bit more searching this morning... One good writeup.

One thing I found was a recommendation against using hydraulic cement against to hold the copper in the sleeve. Same article says not to use silicone caulking since it can affect copper.

"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."

I also found this:

http://www.copper.org/applications/plumbing/techcorner/problem_embedding_copper_concrete.html

According to the Portland Cement Association the interaction of copper with both 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.

I'm going with a two step system.... The entire pipe gets a heat shrink sleeve. The sleeve is sealed to outer 4" of concrete and the tubing with urethane sealant. That allows for expansion and abrasion protection.

That saves me from having to make a 2" diameter hole all the way through the wall. I actually have to bring four lines in. Two for hot water and two for a future solar project.

The inside, side of the foundation wall gets opened up for a 2" OD PVC sleeve. I will open up the hole about 4" deep. The PVC will be sealed to the wall with hydraulic cement. The pipe is sealed to the PVC with urethane caulking.

The shrink sleeve will cover the copper line all the way up to the PEX. The lines all have foam insulation sleeves. A sheet of plastic goes against the foundation. A bed of gravel placed a few inches under pipe to provide drainage away from the wall. The pipes get back-filled with clean sand.

 

[djjsr]

For what it's worth, I grew up in an early 1950's built house with radiant heat (copper pipe direct in concrete slab). By 1971, there were multiple leaks due to corrosion!!! All the house's in that area had the same problem!

I vote for keeping corrosive concrete away from copper!!

Me too, in Levittown, PA. My house was built in '54 and leaks began in '74. First time it happened, there was a big wet spot on the carpet and I yelled at the dog. She probably thought I was nuts.

No radiant heat for me ever again. (and I don't trust pex for hot water)

 

[BD1]

''I'm bringing copper six inches away from the wall and connecting to the pex outside the foundation. That seems to be the norm.''

WHY ???? Run the pex inside to avoid a outside joint. Much easier connecting and monitoring a joint inside then one buried outside.