Laying Pipes in a High-Rise

Residential plumbing isn’t always just about homes: there are apartment buildings that require adequate plumbing and sometimes installing pipes in that situation can be very challenging. This situation presents issues surrounding how to ensure all floors have equal water pressure, how to make sure all floors have equal distribution of water, how to save water, how to most efficiently get the water to the upper floors when gravity is working against it and so on. Here are some things to consider when laying pipes in a high-rise building.

Pressure Reducing Valves

These are usually only installed on the first few floors because as water moves up the pressure will drop naturally thanks to gravity, but these might not actually be needed with a system that matches the needs of the building accurately. They come in different quality levels, like most products, however a lot of buildings don’t use the highest quality in an effort to save time and money. What this means is that they wear down quicker, they have a lot more leaks and will experience significant pressure differentials.

Pressure Ratings

Pipes have different categories with regards to the amount of pressure they can withstand, and a high-rise building’s water system should take into account these various types of pipes and determine which are appropriate for this building. The system designed should be looking at the minimum pressure needed for the fixtures on the highest floor of the building and then ensure that at least the pressure is maintained, especially during peak hours like 7 – 9 am and 5 – 7 pm. However, they also need to consider the maximum pressure amount for the fixtures on the lower floors. The ultimate goal is to ensure the fixtures on the top floor have enough pressure and those on the bottom floors don’t have too much so that the water is distributed equally among all floors in the building.

Maintenance

Most high-rise buildings have full time, or at least part time, maintenance staff. It is really important that these staff have experience and training in the problems of plumbing with high-rise buildings. If the owner cannot hire full time staff with this experience it is strongly recommended to outsource the tasks to a company with experience who can monitor the water system and recommend maintenance before the issue becomes too big. If staff don’t have proper training and attempt to fix a problem they can actually make it worse and end up causing bigger problems.

Drainage

While, in theory, it is water in and water out what some forget to account for is that with drainage comes a considerable amount of air in the pipes. What’s more is that not all pipes will drain vertically; some, due to design or even lack of space, will drain horizontally but when that happens the rate of drainage significantly decreases so design should take that into consideration when working on the architecture of the building and to make sure everything will drain properly and safely from the building.

Fire Protection

It is a building code that all high-rises must have a working sprinkler system on all floors. These systems are effective in preventing damage and saving lives but the number of sprinklers needed, location and coverage are all dependent on building size. In addition to that, high-rise buildings often have a dedicated pump for just that system to ensure the right amount of pressure and flow is provided when the system is needed. It’s important when designing a water system for a high-rise to keep this system in mind when placing equipment and thinking about the required allotted space.

 High-rise buildings are home to many people, and they are very common in large cities where living space is harder to find. High-rises come with their own unique set of challenges when it comes to designing a water system where all residents get equal water distribution both in temperature and amount, and one that meets all building code. When gravity is working against the design, accurate pressure and flow is pivotal to ensure all residents are happy and their fixtures work the same.

Laying Sewer Pipe

They aren’t always fun to talk or think about but sewer pipes are an important part of any community’s water system, and it’s even more important they are installed and run properly to avoid backups into houses, drinking water or fresh waterways. When laying a new sewer pipe it’s vital to follow the appropriate steps, so here are the steps to follow in order to ensure the pipe is installed correctly and will not cause any issues in the surrounding community.

Determine Elevation

First things first: you have to know how far this sewer pipe is going, whether it’s connected to any specific fixtures or other extending pipes and, most importantly, the installation height. The general guideline is that sewage should run downhill and away from communities so you need to know the initial and final elevation, measured at the interior point of the connecting pipe. This can be done using a laser level, GPS or regular surveying equipment.

Slope

With the elevation and the pipe length known you will then need to figure out the pitch, or fall, of the sewer pipe. To do this, subtract both elevations and divide the horizontal pipe length into the difference in elevation. This gives you the drop per foot or meter of pipe. Something to keep in mind is that if the drop is greater than ¼” per foot won’t work while a slope that’s too small (less than 0.003” per foot) will not be adequate either. Ideally, for 4” piping, a 1/8” to ¼” per foot is recommended.

 Trenching & Bedding

You will need to dig a trench to lay the pipe itself in. Make sure you are following all safety procedures for workers completing the trench. It is recommended to grade the trench, and remove all loose dirt, so that the pipe is installed on a smooth service. You might have to use some bedding to provide the required support for the pipe being installed. The best bedding material to use is sand, but gravel is a close second should sand not be available to you. Make sure the bedding you do end up using doesn’t contain any sharp stones as these could puncture, or wear away at, the pipe and cause issues or require a replacement pipe prematurely.

Laying the Pipe

Once the area has been properly prepared it is time to lay the pipe. Usually it is recommended to start at the bottom and work your way up to the higher elevation. If the pipe has a bell end on it then the bell must be placed on the uphill side so as to reduce the possibility of leakage. Also, make sure to apply the PVC primer before applying any PVC glue.

Final Section

It is very possible that the last section of the run will only need a portion of a full pipe, but it’s important to know that you will also need other fittings to complete the pipe installation. Once the installation is complete, you should check along the run to make sure none of the previously installed pipes are leaking, cracked or otherwise damaged potentially from the installation.

If there aren’t any damages or leaks you can start covering the pipes with sand or gravel (as you used in your bedding material) making sure you cover the pipe by at least 10” with this material. Then the ground can be compacted – as appropriate for this kind of piping – and soil can be added on top. It is also important to put a warning tape just over the first layer of soil so that if this area needs to be excavated in the future others will be aware that there’s a pipe underneath.