For Your 4WD, Ute, Caravan or Boat
Setting up water storage for your next trip? Maybe you’re fitting out a 4WD, planning a fishing weekend on the boat or making better use of space in your caravan. Before you worry about litres, start with a simpler question: where is it going to sit?
The best bladder is one that fits your space, is properly supported and is easy to fill and use. Here’s how to work it out, step by step.
Not sure how much water you need? Have a read of our 4WD Water Needs & Payload Guide for Safe Travel.
Step 1: Measure your space
Pick the spot first. Popular places include:
- The rear footwell
- The cargo area
- A ute tray
- A drawer compartment
- Behind the seats
- Under a seat, platform or deck on a boat
Grab a tape measure and write down the length, width and height in millimetres. Then look for anything that might get in the way:
- Transmission humps and centre consoles
- Seat rails, brackets and moving parts
- Wheel arches
- Sharp edges or rough surfaces
- Space needed for fittings and hoses
Handy tip: Measure the available installation space. Because the bladder is flexible, a model approximately 100 mm larger than the space may still fit, depending on its shape and your setup. Check fitting and hose clearance, and confirm suitability with our team before ordering.
Stuck? Send us a few photos and a rough sketch with your measurements. We’ll help you find a suitable fit.
Step 2: Pick a shape that suits your space
Bladders come in different shapes for different spots. Here’s a quick guide:
| Your space | Bladder to consider |
|---|---|
| Flat floor, ute tray or cargo area | Box-shaped (B) |
| Rear footwell with a transmission hump | Hump-cutout (BH) |
| Footwell with a centre console | Box with console cutout (BC) |
| Footwell with a console and a high transmission hump | Box with dual cutouts (BDC) |
| Shallow space, under a platform or a boat installation needing a lower profile | Low-profile pillow (BLP) |
| Behind the seats or beside a cargo barrier | Tall or hanging-style (H / CBH) |
| Cavity behind the rear quarter-panel trim | Vehicle-specific rear quarter-panel bladder |
| Irregular compartment | Custom-shaped |
Box-shaped bladders
Box-shaped bladders work well in a clear, rectangular space. Because the material is flexible, unsupported side panels can bulge outwards as the bladder fills.
Check the surrounding support and allow enough room for the filled bladder, including clearance around the fittings.
Hump and console-cutout bladders
These designs help make the most of your rear footwell by fitting around a transmission hump, a centre console or both.
Your vehicle’s make, model and year are a good starting point, but always measure your actual space, including the usable door-to-door length. Trim levels, factory storage and accessories can all change what fits.
Check the hump height, width and position, along with the console clearance.
Low-profile pillow bladders
Pillow bladders are made from top and bottom panels joined together, with no separate side panels. They expand into a rounded pillow shape as you fill them.
They’re handy in shallow spaces where a taller box bladder won’t fit. Keeping water weight low can also be useful in vehicles and boats.
Allow for the maximum fill height, and make sure the bladder is properly supported and restrained.
Tall and hanging-style bladders
These designs suit some spaces behind seats or next to a cargo barrier. They must sit fully on the floor, with suspension helping them keep their shape.
Check that you have suitable suspension points, and follow the support requirements for the design you choose. Never let the fittings or hoses carry the bladder’s weight.
Rear quarter-panel drinking water bladders
These designs use the cavity behind the rear quarter-panel trim, helping keep your footwell and cargo floor free for other gear.
Fitment depends on your vehicle’s model, year and the components inside the cavity. Before ordering, check the usable space. You may need to remove the trim to take accurate measurements.
Look out for fuel filler pipes, air-conditioning equipment, speakers, wiring and brackets that could affect installation.
Plan access for filling, the breather and the outlet, and check how the bladder will be supported and secured. Send us your vehicle details, measurements and photos of the cavity so we can help confirm a suitable design.
Custom-shaped bladders
An L-shaped, tapered or custom design may help you use an awkward space.
Send us photos and a dimensioned sketch. We’ll review the shape, estimated capacity, fitting positions and support requirements together.
Setting up for a fishing trip or boat?
Fresh drinking water is easy to forget until you’re a few hours from the ramp. A low-profile pillow bladder can suit some boat installations, including beneath a seat, platform or deck.
When choosing a location, think about how the boat’s movement will affect the bladder and its connections:
- Keep the weight low and secure. Support and restrain the bladder so it cannot slide or shift.
- Check the boat’s load limit. Remember that 100 litres of water weighs around 100 kg. Consider its position alongside passengers, fuel and gear.
- Plan access. Make sure you can reach the filler, outlet and breather once your tackle and esky are on board.
- Protect the material. Cover exposed bolts, brackets and rough surfaces that could cause rubbing.
Not sure what suits your boat? Send us photos and measurements of the space, and we’ll help you work out a suitable option.
Step 3: Choose a capacity you can carry
Think about:
- How many people are travelling
- How long you’ll be away
- Whether the water is for drinking only or also for cooking, washing and showers
For help estimating your needs, read our 4WD Water Needs & Payload Guide for Safe Travel.
Then think about weight. One litre of water weighs approximately one kilogram. A full 100-litre bladder adds roughly 100 kg before you count the bladder and accessories.
Check your vehicle’s payload or boat’s load limit, along with the load rating of the supporting floor or platform. Pick a capacity your setup can safely carry and support.
Step 4: Think about filling and drawing water
Picture your setup fully packed, then ask yourself:
- Can I reach the filler without moving the bladder?
- Will I use a tap, a pump or both?
- Where will the hoses run?
- Can I access the breather?
- Will any fitting press against a seat, wall or bracket?
Fitting arrangements differ between designs. Some have separate fill and outlet points, while others use a combined inlet and outlet.
Confirm the fitting sizes and positions for your model before buying hoses, adaptors or a pump. Keep the breather open during filling, following the supplied instructions.
Step 5: Give it a smooth, supportive base
Before you fill the bladder:
- Clear away sharp objects.
- Cover exposed bolts and rough edges.
- Check that the base supports the bladder across its whole footprint.
- Let hoses run freely so they do not pull on the fittings.
- Check clearance around seat rails and moving parts through their full range of movement.
- For taller designs, confirm whether suspension flaps or other support are required.
Check the space with the filled shape in mind, including any outward expansion.
Step 6: Make sure it’s made for drinking water
Always choose a bladder made for potable water. Do not use a grey water, non-potable rainwater or fuel bladder for drinking water, and keep your drinking water bladder dedicated to potable water use.
Fleximake drinking water bladders come in two material options:
Suitable for regular use.
An option for extended trips and tougher conditions.
Both drinking water material options are tested to AS/NZS 4020:2018 for suitability for contact with drinking water.
Use drinking-water-compatible hoses and accessories, and follow the cleaning and storage instructions supplied with your bladder.
Before you order, have these ready
- Available length × width × height in millimetres
- Measurements of any hump, console or wheel arch
- Your preferred capacity
- How you plan to fill and use the water
- Your vehicle’s payload or boat’s load limit
Need a hand?
Setting up a 4WD for camping, adding water storage to a ute, fitting out a boat for a fishing trip or working around an awkward compartment?
Send the Fleximake team your photos and measurements. We’ll help you choose a suitable standard drinking water bladder or talk through a custom design.
