Obviously none of the people who have responded have even a remote clue about how to properly size a line. When designing a potable water distribution system you begin by selecting all the end use fixtures to determine what the end use load will be. In the case of the original post they want a shower head, body sprays, a hand shower and possibly a rain shower head. Quote:"How many fixtures will you have on at any one time? Remember that 3/4" pipe has double the capacity of 1/2" pipe." Code requires that we design a potable water system for a worst case scenario. The system must be capable of maintaining the code listed minimum fixture "Dynamic head pressure" even when every fixture in the house is turned on at the same time. The statement that a 3/4" pipe has twice the capacity of a 1/2" pipe is not true. The capacity, or properly the volume of flow is determined by the size of the metering orifice in the end use fixture. It is true that a 3/4" line has double the cross sectional area of a 1/2" line however both will supply the same volume, the difference being that the velocity of flow will be twice as fast in the 1/2" pipe. The problem here is that as the velocity of flow increases the "fiction head pressure loss" increases dramatically. In addition to the loss of pressure due to friction head if the velocity of flow exceeds 8fps we start seeing sever pipe wall erosion, which leads to premature pipe failure. In fact, while acidic water is the leading cause of pin hole failure in copper pipe, excessive velocity in undersized pipe is the second leading cause of pinholes. Preferably we should have the end use fixture data available when designing the system but in situations where that information is not yet available we use the gal/min flow rates that are published in the code. Now getting back to the original question. All the end use fixtures in question are types of shower heads and per code shower heads are restricted to 2.5gpm so let us begin putting it all in perspective. Using the code standard of 2.5gpm we get shower head (2.5gpm), hand shower (2.5gpm) and body sprays (2.5gpm)equals and a hand shower(2.5gpm) for a total load of 10gpm. Consulting the "Type L Copper Friction Loss Table" we find that if we supply this shower with a 1/2" line the velocity of flow would be 13.80ft/sec and the pressure loss would be 67.72psi/100ft of pipe. If we increase the pipe size to 3/4" the velocity of flow is 6.62ft/sec and a pressure loss of 11.17psi/100ft.

afaik. each province has its own code, and they all allow 1.5" drains. Everyone says so, but I've never seen it in writing. Check with a Master Plumber. Any Master Plumber. They are professionals who do not lie. They know 100% for certain what is required and they tell you the truth, when it concerns their expertise; also you do not have to hire them first before they answer questions about their area of expertise. Each Master Plumber will give you the same answer as the previous one and the next one. Ditto, do not decrease any "drain line in the direction of flow." The trap size has to be the same as the drain size. Many people conclude that a 2" trap can be reduced to a 1.5." pipe after the trap. Use a 1.5" trap if the drain line is to going to be 1.5" diameter. This is very serious, not to be disregarded. Ask a Master Plumber if you need to hear it again. You may wonder why you see on the internet that showers need 2" ... I feel that this forum is the right place for this discussion. It find the 2" diameter requirement for showers to be overkill. I'm surprised that after many years of searching, I've never seen an internet comment from an experienced Master Plumber telling me how Code changed over the years. I'm 100% certain that a 1.5" drain line used to be Code everywhere, for showers. I'd like to know what discussion went into voting for the new size, 2" diameter. (?) Here is a link showing 1.5" is OK in NY. http://publicecodes.citation.com/st/ny/st/b900v07/st_ny_st_b900v07_7_sec009.htm Code has changed over the years and will continue to change in the future. I'd like to think I'm helping to air out the issues which leads later to clearing up confusion about 2" shower drains. Imagine all the people who have been forced to do a lot of extra work for no reason !! When a 1.5" drain already plumbed could have been used, they ripped it all out and put a 2" drain in. I'm not a plumber. Since this is a discussion forum, I'm posting this here as part of a *discussion*; everything I have written here concurs with the previous post from an expert who knows, and who shares, precisely what is code today. Code has changed over the years and will continue to change in the future.

Thank you Annz. One of the installers called me back so he is the one I will use to install the floor. He is the middle of the price range and he told me he will take a break from the job he is on tomorrow to come by to let me know exactly what we need but from my description he feels I need 2 T-moldings (88" long and I need 4" more than this from my measurements for the two areas) and the reducer will not be good if the area is only a 1/8th difference. But he will see for sure and bring a floating pad and a 1/2" board. He also will let me know the exact number of reducers we will need since they are not returnable I just found out. He feels we have enough extra waste for the wood and he is very good at not wasting wood and is good at what he does. Hence, I guess I will wait for him to arrive tomorrow. Truehardwoods.com has been so patient with me and will give me a few more days (they have the order in the system but it is not yet sent to their distributor) to be sure about what I need as well as let me know which glue I ordered to allow me to change the wood glue to waterproof glue between the seams. Another installer just called me back and had no idea and that is not a good sign. So if the installer comes by tomorrow that called earlier, he has the job. I guess I better get back to my work and get a good night's sleep tonight and see what the installer has to stay that is stopping by tomorrow.

Yes, we have oak floors in 2 bathrooms, the entry ways, and the kitchen and other than the kitchen floor, which just needs to be refinished, the oak floors are in great shape. The carpet, although original to the 1984 house is top notch and no matter what I spend, I can't find a carpet like it. The carpet is badly worn out in the hallway and family room. So, I'm going to take the carpet from my living room and dining room and have that replaced with hard wood flooring which butts up against the entryway and the kitchen. I'll take the carpet from the living room/dining room area and have that installed in the family room. I was hoping to have the new oak floor in the living room/dining room installed in a chevron pattern. So, although I could go with an engineered product, I'd prefer to find a match to my existing floor. The hardwood floor would also be installed in the hallway.