Fitting Prolock Sigma plastic bank protection is a job many home owners do themselves. The panels are lightweight, the sliding system is straightforward and the build-up is clear. It is a fine do-it-yourself job, if you prepare properly.
This step plan walks through the complete process, from getting ready and the strength check to fitting the last capping beam.
Before you start: materials and tools
Materials you require
- Prolock Sigma panels: bank length divided by 0,50 m panel width. Pick height from the strength check.
- Wooden posts of 10cm: one post per 1,00 m to 1,50 m. Use round milled spruce or hardwood.
- A capping beam: bank length divided by 6,00 m. Optional, but a very proper idea.
- Capping beam connectors: one less than the number of cover caps. They join the beams.
- Corner profiles: one per corner over 15 degrees. They adjust from 10 to 110 degrees.
- Cover caps: two pieces, one for the start and one for the end.
Tools you require
- A measuring tape and a spirit level for the guideline.
- A wooden pile driver or a vibrating hammer, by hand or machine.
- A shovel or a mini digger for the excavation.
- Pickets and rope so you can set out a straight line.
- A saw, in case you need to shorten posts.
- A hammer or a sledgehammer for driving the posts.
Step 1: Project prep and permits
Always start by mapping out your undertaking and put the sizes on paper.
- Measure the length of the sheeting you want, and do it with precision.
- Determine the height gap between the water line and ground level.
- Ask your water board whether a permit or a notification is necessary.
- Check for cables and pipes. Call the free KLIC line on 0800-0080.
Note: Most water boards set regulations on the distance to the water line and on the variety of material. Some towns add additional rules for walls higher than 1 metre typically.
Step 2: Strength check
The strength check sets the panel height and the space between posts. That hangs on:
- The soil type, including clay, peat or sand.
- The height gap the bank wall must retain.
- The water level and the ground water level.
- The load above the wall, such as vehicles or storage.
Guidelines:
- Height gap up to 30cm: use a 50cm panel and 1,50 m between posts.
- Height gap 30 to 60cm: use 80 to 100cm panels and 1,25 m between posts.
- Height gap 60 to 100cm: use 120 to 150cm panels and 1,00 m between posts.
- Height gap over 100cm: use 200cm or more. A strength check is then a must.
Need a free strength check? Houthandel Jan Sok will prepare a complimentary calculation and a fit plan for your site. Call 0522-851551 or email info@houthandeljansok.nl.
Step 3: Set out the line
- Drive pickets into the corners of the planned bank wall.
- Span a rope between the pickets. This is your guideline.
- Check with a spirit level whether the line sits level.
- Mark the post spots on the line, at most 1,50 m centre to centre.
Tip: Always start at a fixed location, such as an established wall or a jetty. Work from there so you stop the line from tilting.
Step 4: Drive the posts
Now you drive the wooden posts into the ground and proceed steadily.
- Start with the corner posts. They determine the position of the rest.
- Drive each post at least one third of its full length into the ground.
- After each post, check that it is upright and on the string line.
- Use a pile driver on top of the post so the head does not fracture.
- Work from one corner to the other in a steady order.
Driving tips per soil type
- Peat or soft clay: drive by hand. The post sinks easily, so utilise a longer model.
- Clay: drive by hand or with a vibrating hammer. Pre-drill to half depth in compact clay.
- Sand: use a vibrating block or water injection. Spray water alongside the post while you drive.
Step 5: Fit the Prolock panels
This is the moment where the system demonstrates how straightforward it is.
- Take the first panel and lower it from above between the first two posts.
- Slide the panel down to the depth you require.
- Take the next panel and slide its lock edge into the last panel.
- Push the second panel down and repeat this for the complete length of the wall.
- Check often that the tops of the panels remain level.
Important: The lock join allows a small bend of at most 15 degrees. For sharper corners, such as around a pond, use the Prolock Sigma corner profile. That allows angles from 10 to 110 degrees.
Step 6: Fit the capping beam and finish
The capping beam is the horizontal finishing strip that remains on top of the sheeting.
- Place the capping beam on top of the panels and posts.
- Click the capping beam over the top of the panels.
- Join more than one beam with a connector for a seamless connection.
- Place cover caps on the ends.
The capping beam does several jobs:
- It protects the top of the panels and provides a sleek, finished appearance.
- It prevents soil and debris getting behind the panels.
- It increases the stiffness of the structure.
Mistakes we frequently observe
Avoid these pitfalls, as they cost time and money later.
Posts too far apart
More than 1,50 m centre to centre reduces stability a lot. For higher walls over 100cm, 1,00 m is a better pick.
Posts not deep enough
The rule of thumb is at least one third of the post length in the ground. On soft soil, go even deeper. A post of 3 metres must then sit at least 1 metre in the ground.
No strength check on higher walls
For walls higher than 1 metre, a strength check is essential. Earth pressure rises with the square of the height. A wall of 2 metres must take four times the force of a 1 metre wall.
Panels not deep enough in the ground
The underside of the panels must sit below the water line. If not, soil will wash away under the sheeting.
Wrong choice of post
Do not use preserved posts right next to water. The chemicals can pollute the water. Choose untreated pine or hardwood.
How much material do you need?
A worked example for 10 metres of wall with panels of 100cm:
- 20 pieces of Prolock Sigma 50 by 100cm at 34 euro 50: 690 euro.
- 8 spruce posts of 10cm and 2,00 m, at 1,25 m spacing, at 9 euro 50: 76 euro.
- 2 cover plates of 6,00 m at 175 euro: 350 euro.
- 1 connecting piece at 11 euro: 11 euro.
- 2 cover caps at 3 euro 80: 7 euro 60.
- Total: 1134 euro 60.
That comes to about 113 euro per metre, including all materials.
Conclusion
Fitting Prolock Sigma is a manageable job. Most people who work with their hands can do it with the right prep. The keys are a sound strength check, the right post, and accurate setting out.
Unsure about the right approach for your site? Houthandel Jan Sok in Meppel is happy to help with a free strength check, a materials list and advice that fits.
Call 0522-851551 or email info@houthandeljansok.nl. Shop: houthandeljansok.nl.
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