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miguelito3218 · Oct 11, 2006, 10:30 AM

If you want to replace the water lines in a slab, one story house, can you just go up into the attic and come down to each fixture?

When going from an existing copper line to cpvc, can you use one of those male adapters like you would use on a shower body or water heater?

Also, water heater is fed by a 1/2 line, which only services on bath and kithen. I'd like to in the future run a 3/4 line to the water heater, then a 3/4 line to service all the hot water fixtures, in the future. Because I am currently building a new bathroom, can I run the 3/4 line to the new bathroom, then just cap it off in the attic until I get to redoing the kitchen and other bath in the attic? (so it would be 1/2 feeding the water heater with 3/4 outlet until I get around to replacing the feed to 3/4)

Could I just tap off the 3/4 line to 1/2 for each fixture, or do I have to tap off once and feed my other fixtures off the 1/2 line? Thanks for all the help from this site.

dmkegs · Oct 11, 2006, 06:17 PM

Originally Posted by miguelito3218

If you want to replace the water lines in a slab, one story house, can you just go up into the attic and come down to each fixture?

When going from an existing copper line to cpvc, can you use one of those male adapters like you would use on a shower body or water heater?

Also, water heater is fed by a 1/2 line, which only services on bath and kithen. I'd like to in the future run a 3/4 line to the water heater, then a 3/4 line to service all the hot water fixtures, in the future. Because i am currently building a new bathroom, can i run the 3/4 line to the new bathroom, then just cap it off in the attic until I get to redoing the kitchen and other bath in the attic? (so it would be 1/2 feeding the water heater with 3/4 outlet until i get around to replacing the feed to 3/4)

Could i just tap off the 3/4 line to 1/2 for each fixture, or do i have to tap off once and feed my other fixtures off of the 1/2 line? Thanks for all the help from this site.

You need to check code in your area, but a 3/4 will feed 4 fixtures without you being scalded in the shower when some one flushes the toilet. As far as put your new lines in the attic remember that they must be protected from freezing. I would take care of the supply to the hot water tank first. Run 3/4 with 3/4X1/2 tees to the present and future fixtures

miguelito3218 · Oct 11, 2006, 06:52 PM

Thanks! But when I carry the new 3/4 hot line through the attic, I need to feed more than 4 fixtures. I would need to feed 7 or 8 (2 baths plus kitchen sink, plus washer). So how would I go about doing that? The 3/4 line would be direct from the hot water heater.

iamgrowler · Oct 11, 2006, 07:40 PM

If you permit this job you may run into problems with the plumbing inspector.

Most jurisdictions do not allow water piping to be run in unheated spaces, which in most cases, means an attic is out of the question.

If you were to run the piping overhead, you would need to drill it through the rafters, which will likely be frowned upon by the building inspector, you will then need to insulate the rafter bays and sheet them in with plywood -- Which probably presents a whole host of other problems if the rafters aren't substantial enough to support the added weight.

If this is merely a hot water issue, are the bathrooms close enough together to install a Rinnai tankless hot water heater?

This would certainly beat undermining the rafters in your attic just to get the new system past the plumbing and building inspectors.

miguelito3218 · Oct 12, 2006, 08:12 AM

Thanks again! I live in Florida so I don't think the heating issue is a problem... could I not just run them along top of the rafters rather than drill through? Thanks!

speedball1 · Oct 12, 2006, 08:59 AM

"If you want to replace the water lines in a slab, one story house, can you just go up into the attic and come down to each fixture? "
Yes, This is called "overhead piping"and we use it when we pipe our condos here in Florida.

"When going from an existing copper line to cpvc, can you use one of those male adapters like you would use on a shower body or water heater?"
Yes you may use a threaded male to threaded female adapter to convert from copper to CPVC.

I'd like to in the future run a 3/4 line to the water heater, then a 3/4 line to service all the hot water fixtures, in the future. Because I am currently building a new bathroom, can I run the 3/4 line to the new bathroom, then just cap it off in the attic until I get to redoing the kitchen and other bath in the attic? (so it would be 1/2 feeding the water heater with 3/4 outlet until I get around to replacing the feed to 3/4)"
Increasing the hot water feed to 3/4" is a very good idea. You may run a 3/4"main and cap it off untill needed. A 3/4" hot water branch to each fixture is overkill and I'll address that later and this post.

"Could i just tap off the 3/4 line to 1/2 for each fixture, or do i have to tap off once and feed my other fixtures off of the 1/2 line?"
As I stated,"overkill". Code allows three fixtures off a 1/2" branch fed by a 3/4" main. However I would run a dedicatel 1/2" supply to the toilet. That saves someone in the shower from getting parboiled when the toilet's flushed. Regards, Tom