Fibreglass Swimming Pool Installation: DIY

Our friendly, supportive team at Pools for Africa are committed to ensuring clients have all the necessary information to start their fibreglass swimming pool installation journey. Those who opt for a DIY install will benefit from our detailed guideline. Keep reading for more insight into the installation of fibreglass swimming pools.

DIY Swimming Pool Options

Basic – includes the fibreglass pool shell and a weir/skimmer box and aim-flow fitted.

Standard (recommended) – includes the fibreglass pool shell, weir/skimmer box, jets and a LED light fitted as standard.

Delux – all the same fittings as the Standard option, but with expert hand-lamination.

Plans and Planning Permissions for Swimming Pool Installation

Familiarise yourself with building restrictions and planning permissions required in your area before planning your pool installation.
Using utility plans if available, determine whether any utilities will interfere with the placement of your pool. If not available, use above ground evidence, e.g. manholes, to assess whether there are likely to be utilities that need to be moved.
Determine the exact size and shape of the pool and, if you are not comfortable drafting plans, contact a draughtsman or architect to assist with your minor works plans for submission should you require planning consent.
At the same time, determine where you would like to place the pump and filter, as this will impact the type of pump and filter and quantity of materials you will require.
Once the required permissions have been received, order the pool and fix a date for delivery.
Note: Most swimming pool manufacturers require the buyer to offload the pool on site, so please ensure that there are enough hands or the correct machinery is on site for delivery.

Mark Out

Once on site, measure the exact dimensions of the pool. Ensure that measurements are taken on all sides of the pool and note down these measurements.
Mark out the exact shape of the pool on the ground, allowing for a 250-400mm over dig, using rebar pegs and string, paint or chalk. The 400mm allows space for backfilling the pool. (With clay conditions increase the quantity of your over dig to allow for the additional movement). Ensure you also mark out the position of the weir/skimmer.
Select a fixed datum point like a concrete patio or a mark on the fence. This datum point will then become the reference point for all measurements.
All pegs are to be marked for the datum level which is the exact pool height lip or flange. Mark with tape, paint or hammer peg down to exact height. Transfer datum to other pegs using a water level (see-through pipe filled with water).
Note: When selecting the datum, remember to allow for the pools finishes e.g. timber deck +-25mm thick, paving +-40mm thick, or tiles +-12mm thick, a cement bed and adhesive for tiles roughly 10mm.

Excavation for Swimming Pool Installation

Excavate the pool with the sides as vertical as possible.
Using the measurements above, ensure that the depth is a minimum of 50mm deeper than the pool to allow for a sand/crusher dust screed.
If the depths of the pool shell is 1m to 1.7m, then the depths of the excavation should be 1.05m at the shallow end and 1.75m at the deep end, all measurements are in relation to the datum point
The depth of the pool before bedding is always measured by placing a string across two datum points and measuring vertically down. Take your time with this. The best pool builders will take their time, focusing on getting these measurements spot on. Any errors will result in a lot of additional work.
Place new pegs or bricks in the deep and shallow ends according to the depth measurements.

Pool Bedding and Swimming Pool Installation

String a line between the left side deep and shallow ends base pegs and then the right side. Some people temporarily lay bricks from deep end to shallow end on the left and then right-hand side, while others use temporary levelling timbers.
Throw a bed of river sand or crusher dust that just exceeds the required depth. Thoroughly compact the sand with a heavy batten plate or boots and make sure you wet the sand so that it is easy to screed and compacts easier.

Use a straight edge on your brick lanes or levelling timbers to the pull the screed to the required depth. Then remove bricks or levelling timbers and fill the cavity tracks they left.

Check your datum and then your pool depth and finally stand back and check for stones in the bedding.
If you are not confident, repeat procedure until satisfied your pool will be level and the base flat.
Again, take your time. It is essential that the pool is level.

Placing the Pool Shell in the Hole

If not pre-installed, now is the time to install the weir/skimmer, light and aimflow/jets.
Depending on the size of the pool shell, you may need some assistance with this step.
Lift the pool on the corners of the rectangle (never the bay as this could cause gel coat cracks).
Lift and move the pool to the shallow end of the hole and then slightly overhang the pool in the shallow end.
Get two or three people under the pool and carry the pool on the bedding into the deep end. The best way is on your back
Note: No pool is worth long-term injury, so be sure to put the safety of the workers first, enough manpower is the key.
Once in the deep end, two to four helpers should hold up the pool in the deep end allowing the braves below to exit from the nearest and easiest point.
Place the pool as gently as possible onto the compact bedding and line up to your plan and pegs. Check and check again.

Final Adjustments

Once in position, check your datum level. Start on one side and move around the pool using your water level. If one or more sides are marginally out, lift the pool while one guy using a trowel throws sand under the corner that is being raised. You are trying to level the rim of the pool so concentrate on the sides at the base of the pool. The inside floor of the pool is flexible and is not as important as the level of the pool.
Should the levels be significantly out, lift the pool out and start again making sure your measurements are correct. Each pool is different and thus requires discretion. Take your time as you only get one chance. Use a straight edge and level on all four sides to ensure the sides are level.

Backfill for Swimming Pool Installation

Start filling with water.
Tie a string/fish line on both sides to the flange of the deep end and the shallow end in line with the edge of the pool. Use a hacksaw to make a small cut into the flange to hold the string. The two strings will act as a guide during backfilling, ensuring that the edge remains straight.
“Lock in” the pool by backfilling the first 300mm in sand or crusher dust only and saturate thoroughly. Ensure that the sand firms up by pushing a batten into the soil whilst saturating.
Backfill using 1:10 cement to river sand mix (this is a minimum). Some installers will use a 1:6 mix. Alternatively, crusher dust can be used to backfill.
When backfilling a fibreglass pool it is the industry standard that the pool is filled 300mm at a time: 300 mm water in the pool, then 300mm backfilling. This is continued to keep the sides of the pool straight.

The pool may naturally bulge as the water increases. Let the edge go beyond the string line before backfilling and compacting by foot, straightening the edge again. If the edge of the pool goes beyond the line, remove some of the backfill. Take your time to get this right.
Under the steps and seats, using the same cement and sand mix, use a small batten to force the sand into any hollow spots. You can tap on the step to see if it is still hollow. Get in there as low down as possible, but at the same time ensure that you do not damage the shell with the batten.

Plumbing & Filtration

Once you get to the base of the weir/skimmer, it is time to complete the plumbing and filtration of the pool.
Position the pump and filter as near as possible to the pool and as close as possible to the same level as the pool.
Temporarily put the pump and filter on bricks and level.
Connect the pipes using PVC cement and ensure that PTFE tape is used on all threaded pump and filter connections. Tighten by hand and gently use water pump pliers to tighten with one more quarter turn.
Do not insert the jets until you have rinsed the pool piping on the multiport valve. Go online and see how pool pumps and filtration work.
Below is an illustration of the pump, filter and chlorinator configuration.

Electrical

Always use a qualified electrician and ask him to issue a COC (certificate of compliance).
Run the cable back to the distribution box and ensure it is earthed.
Where the pool light is connected to twin and earth, make sure the electrician uses a resin box with two connectors to ensure the connection is waterproof.

Ring beam and Coping

At a 100mm from the top of the pool cease backfilling and lay a ring beam of concrete. This is to secure your pool edge in position and give you a secure coping.
The ring beam should be as wide as the coping. The coping overhang should be 30mm on bull nose coping.
The ring beam should be a 1:3:6 mix of cement, stone and sand.
Many installers would attach the pool to the ring beam with ties, drilling holes in the flange and concreting pegs into the ring beam

CONGRATULATIONS!!!! You have completed your first fibreglass swimming pool installation.