Home Page link

Plumbing - Pipe size question

Home| Search | About
Login Password
Register Now! Lost Password?

Home Repair - - If it ain't broken, don't fix it. Otherwise look here. 

Page 1 of 3       1 2 3 > last >> Bookmark this page:  YahooMyWeb Yahoo!  Google Google  Windows Live Favorites Windows Live  del.icio.us del.icio.us  digg digg  Add to Netscape Netscape
Subject Author Date
Plumbing - Pipe size question greatyetiofthenorth@gmail.com 05-22-2007
If you were  Registered and logged in, you could reply and use other advanced thread options
Posted by greatyetiofthenorth@gmail.com on May 22, 2007, 2:54 pm
Here's a general plumbing question for the group:

I have a home built circa 1920 and the water main was recently
upgraded to a 3/4" copper pipe. Yet all the copper inside the house
is 1/2". I am going to be redoing my kitchen and bathrooms, and am
considering replacing all the 1/2" pipe with 3/4". Is this upgrade
worth doing? The challenge is that the water pressure coming in off
the street is fairly low, and I am concerned that adding a larger pipe
will only decrease the water pressure that much more.

Thoughts?


Radiant Heat 468x60
Posted by Edwin Pawlowski on May 22, 2007, 3:11 pm

> Here's a general plumbing question for the group:
>
> I have a home built circa 1920 and the water main was recently
> upgraded to a 3/4" copper pipe. Yet all the copper inside the house
> is 1/2". I am going to be redoing my kitchen and bathrooms, and am
> considering replacing all the 1/2" pipe with 3/4". Is this upgrade
> worth doing? The challenge is that the water pressure coming in off
> the street is fairly low, and I am concerned that adding a larger pipe
> will only decrease the water pressure that much more.

No benefit unless you upgrade the main trunk in the feed, but after that,
1/2" is plenty as it is reduced further at the fixtures. The downside is
that for hot water, you have to drain out more water sitting in the line to
get the hot to flow at the fixture.



Posted by EXT on May 22, 2007, 3:28 pm
Feed your hot water heater with 3/4" pipe and make your main cold runs all
3/4" with 1/2" branches to the fixtures. If your showers do not have
temp-pressure compensation you may want to make sure that all the toilets
have the 3/4 main trunk come close to the fixtures with unshared 1/2
branches dedicated to each toilet and the same for the shower valve.

>
>> Here's a general plumbing question for the group:
>>
>> I have a home built circa 1920 and the water main was recently
>> upgraded to a 3/4" copper pipe. Yet all the copper inside the house
>> is 1/2". I am going to be redoing my kitchen and bathrooms, and am
>> considering replacing all the 1/2" pipe with 3/4". Is this upgrade
>> worth doing? The challenge is that the water pressure coming in off
>> the street is fairly low, and I am concerned that adding a larger pipe
>> will only decrease the water pressure that much more.
>
> No benefit unless you upgrade the main trunk in the feed, but after that,
> 1/2" is plenty as it is reduced further at the fixtures. The downside is
> that for hot water, you have to drain out more water sitting in the line
> to get the hot to flow at the fixture.
>



Posted by Sacramento Dave on May 23, 2007, 12:44 am

> Here's a general plumbing question for the group:
>
> I have a home built circa 1920 and the water main was recently
> upgraded to a 3/4" copper pipe. Yet all the copper inside the house
> is 1/2". I am going to be redoing my kitchen and bathrooms, and am
> considering replacing all the 1/2" pipe with 3/4". Is this upgrade
> worth doing? The challenge is that the water pressure coming in off
> the street is fairly low, and I am concerned that adding a larger pipe
> will only decrease the water pressure that much more.
>
> Thoughts?
>

The best thing to do is have a professional size it for you. You are also
getting pressure a volume mixed up. You can't change the pressure with a
larger pipe or smaller pipe. But you will get more volume out of a larger
pipe. Also if you increase the hot water lines ( 1/2 " to 3/4 " ) all you
will accomplish is a longer wait for hot water unless you have a
recalculating pump. Pipe sizes are calculated on fixture unites each facet
toilet hose bib has a fixture unite assigned to it . But one thing the don't
account for is low flow fixtures so if your piping is a little under sized
it might not be worth changing.



Posted by on May 24, 2007, 4:58 am
On Tue, 22 May 2007 21:44:16 -0700, "Sacramento Dave"

>
>> Here's a general plumbing question for the group:
>>
>> I have a home built circa 1920 and the water main was recently
>> upgraded to a 3/4" copper pipe. Yet all the copper inside the house
>> is 1/2". I am going to be redoing my kitchen and bathrooms, and am
>> considering replacing all the 1/2" pipe with 3/4". Is this upgrade
>> worth doing? The challenge is that the water pressure coming in off
>> the street is fairly low, and I am concerned that adding a larger pipe
>> will only decrease the water pressure that much more.
>>
>> Thoughts?
>>
>
> The best thing to do is have a professional size it for you. You are also
>getting pressure a volume mixed up. You can't change the pressure with a
>larger pipe or smaller pipe. But you will get more volume out of a larger
>pipe. Also if you increase the hot water lines ( 1/2 " to 3/4 " ) all you
>will accomplish is a longer wait for hot water unless you have a
>recalculating pump. Pipe sizes are calculated on fixture unites each facet
>toilet hose bib has a fixture unite assigned to it . But one thing the don't
>account for is low flow fixtures so if your piping is a little under sized
>it might not be worth changing.
>

A professional ????
How hard is it to use 3/4" as the main trunk and use 1/2" to each
fixture. Or, if you want to run 3/4" to everything, do it....

BTW: I recommend running 3/4" to outdoor spigots.

Page 1 of 3       1 2 3 > last >>
Similar ThreadsPosted
Re: Plumbing: What size hot water pipe do I need? April 3, 2008, 9:14 am
Re: Plumbing: What size hot water pipe do I need? April 3, 2008, 9:50 am
Plumbing question: getting piece of broken pipe out of drain pipe October 21, 2006, 3:01 pm
Plumbing: Is a larger stack size quieter? January 26, 2007, 1:46 pm
gas pipe size October 30, 2008, 6:16 pm
Water pipe size August 2, 2005, 8:29 pm
What size hot water pipe should I use? April 3, 2008, 7:35 am
Size of pipe to the Septic Tank? August 25, 2006, 1:20 am
size of pipe to shower riser? July 28, 2008, 10:24 pm
Re: size of pipe to shower riser? July 29, 2008, 12:15 pm

Contact Us | Privacy Policy

XML SitemapXML Sitemap