Working with Hydraulics Engineers

Blue water... by ERIO, on FlickrIn Australia hydraulic engineering and wet fire engineering (sprinklers/fire hose reels and hydrants) are often the work of a single engineer on smaller fitout projects.    For this reason I’ve decided to cover these two disciplines together in this one post. In other locations people may be more familiar with the use of the word plumbing to cover these disciplines.  In Australia, we also have fire engineers, who undertake work related to overall fire and life safety systems – which I’m not covering in this post. (Perhaps for another blog post – this series seems to keep expanding!)

The extent of hydraulic engineering works on many fitouts can be quite minor – perhaps limited to a single tea room sink.  Sometimes the fact that the hydraulic engineering works are so limited can mean that sufficient attention is not paid to coordinating this discipline.  Due to recent changes to the accessibility standards  in Australia it has become more and more common that a wheelchair accessible toilet facility will also be part of the fitout.  Installing new toilets into existing building structures greatly increases the need for coordination and early planning in relation to hydraulic items.

In my experience there are three major issues that arise again and again in relation to the hydraulic engineering works.

Clashes with existing structural elements
Frequently what needs to be coordinated is not so much the interior design and the hydraulic engineering or pipe work but the pipework or fixture locations and the structure or other impediments below the fixture.  It is important to try and find out at the very early planning stages what is underneath any rooms proposed to have hydraulic fixtures and in particular toilets.

Sometimes it is not possible to gain access to the ceiling below in order to run the pipe work. For example if there is another organisation’s server room below or if there is a fixed plasterboard ceiling – the costs, risks and difficulties of access may mean that it makes sense to move the toilet or kitchen to another location within the fitout.

The other issue is  locations of structural elements. In particular, this has a major impact upon locations for toilets as usually pipework for sinks, basins or showers can be slightly modified or moved to avoid structural elements.  Generally with a toilet waste this is not possible (there may be 2 options an P or an S trap only).  For accessible toilet facilities this becomes a more significant issue as the location of the toilet pan is quite critical and cannot necessarily be easily moved to accommodate structural elements.  If the room is designed to the minimum code dimensions this may prevent any rearrangment of the room to suit the structure. The best solution to this problem is again to try to obtain the information on the structural design early if possible (and import it into your plans/model so you can check and see it during your design process) – although often this isn’t possible with an existing building. In this case in may be necessary to scan the concrete slab to determine the location of beans or post tensioning cables. Another good options if it is possible, is to slightly oversize the rooms to allow for some future flexibility. The final option you are left with if this issue is discovered only when you are on site, is to install a pump. In my opinion and experience this is a very simple solution for sinks and basins and I have no problem recommending it to clients for these applications. However it’s not something to be recommended for toilets – whilst it is possible – it’s not pleasant when it leaks onto the brand-new carpet! (broadloom of course)

The other information that should be obtained early is the location of hydraulic stacks.  In my opinion as an interior designer or architect you can’t let these drive the fitout planning, as you would often end up with kitchen/breakout areas in the most unpleasant parts of the building with no access to natural light, but you should take them into account and be aware where they are located. That way when someone asks you about why the kitchen is not next to the stack you can explain that you considered them, and the reasoning why you located sinks away from them.

The most important thing is to consider these constraints and gather information as early as possible in the planning process.  By the time we get to a client signoff milestone where we have locked in the locations for rooms such as toilets and tearooms we may not yet have a hydraulic engineer on the project. As interior designers and architects we need to take responsibility for this early coordination.  If there is a hydraulic engineer already appointed it is a good idea to have them review approximate fixture locations prior to finalising the agreed layout with the client.

Sprinklers seemed to be an item which frequently cause trouble on a project. I have never quite understood it but it seems that the sprinkler code in Australia appears to be open to some level of interpretation. I can ask three different hydraulics /fire engineers and get three different opinions as to what the design criteria should be to comply with the code. If anyone else has a solution to this problem and how to manage it I’d like to know!

The other issue that interior designers and architects need to be aware of when it comes to sprinkler design is to ensure that the engineer is aware of any high level elements such as bulkheads, feature ceilings, compactuses or joinery which could impact upon the sprinkler head flow.

Coordination of hydraulic fixtures
Hydraulic fixtures should only be specified once. It does not matter if they are specified by the interior designer or architect or by the hydraulic engineer. However it is important that it is agreed who will select the fixtures and that the other party is given information on what has been selected – and the chance to comment on the selections.

The interior designer or architect also needs to ensure that sufficient space has been left for the hydraulic fixtures including items such as pumps, hot water or boiling water units and the pipework or any ventilation needs associated with these items. Whoever is taking overall responsibility for coordination should also check that the electrical engineer has provided power where required.

The other item that should be checked early on (prior to finalising plans with the client if possible) is if existing fire hose reel locations will be sufficient. If new reels are required ensure to allow space for these too. In Australia, the need for a new hose reel may also highlight that you have an issue with your egress distances so you may need to check these (a hose reel covers 40m – the same distance as the permitted egress path).

Do you have any tips on hydraulic and wet fire coordination? In particular any suggestions on the mysteries of the Australian sprinkler codes? Are there other specific regulatory issues that need to be considered in the countries you work in?

I’m planning further posts on working with sustainability consultants, acoustic engineers and fire engineers – if you have any tips on these topics please email me. As always any suggestions for future blog posts are always welcome too.

Image credits:

Creative Commons Attribution-Noncommercial-Share Alike 2.0 Generic License  by  ERIO 

2 thoughts on “Working with Hydraulics Engineers

  1. Ceilidh,

    Thanks for this well put together article. I’ve put a couple of comments below for consideration:

    – Interior Designers collaborate with the Hyd Engineer & consider using pre-fab modules (such as the Geberit GIS system) which can prove to be cost effective and reduce the construction period.

    – It is imperiative to speak with your Hyd consultant as soon as possible to identidfy potential tea prep / wet area locations to minimise potential issues in making conneciton with the existing services. I know you go into this in some detail, and highlight the need for some of these rooms to receive natural light etc, but I feel that servicing the area is more important than aesthetic needs. Sure, many fitouts have a brief which is more akin to provision of a cafe, rather than a sink with kettle next adjacent the cleaners store, which is fine. It is just worth weighing this up with issues such as accessibility to ceiling space below, contents of ceiling space below preventing a gravity connection, or provision of pumped waste.
    Whilst pumped systems have advanced over the years, and are quieter and more reliable than ever before, they are still a mechanical device which requires care, maintenence and has an ongoing OP-EX which needs to be considered. Particularly on GS / NABERS fitouts, this solution is not generally the best project outcome. As you’ve already said, best solution for all of this is early communication with the Hyd consultant.
    – Great point about the FHR’s. These are often overlooked, or left till last minute. (to clarify, coverage is 36m + 4m throw. This distinction needs to be made, cause you need to get inside the door of every room with a clearance of 1m, within the 36m distance) Also, this isn’t a radial measurement, for obvious reasons it needs to be measured by laying out of a hose along the ground, around desks.
    – Lastly, one thing which has previously caught me out with respect to sprinkers is pendant light fitting. I know you’ve mentioned about bulkheads, feature ceilings, compactuses and the like, but it’s often the large feature lights which are not picked up by your hyd/fire consultant. Perhaps it’s best to put this on the list to warn him of, as these can sometimes provide baffles which break up the spray pattern and lead to coverage black spots.
    Thanks again for an informative post
    D. Preston

  2. Dennis
    Thanks for your comments, some good points there. Now you remind me – I had also heard of the problems with light fittings and sprinklers before, a good one to remember.

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