Precast concrete headwalls and the better alternative from Permashutter: the Patented Polymer Headwall
Tough polymer plastic headwall moulds filled on-site with concrete, complete with ancillaries to reduce construction time to hours whilst increasing the quality of the finished outfall.
Renowned for low cost, speed and ease of installation, Permashutter headwalls are fast becoming the headwall installation method of choice across a wide variety of projects.
When used as an alternative to pre-cast concrete or cast in situ headwalls, Polymer headwalls can offer huge savings in installation time and costs in many situations.
Additionally the finished headwall will have higher quality attributes than the other methods by reducing many of the variable factors from the construction process.
What is a polymer headwall?
A polymer headwall is a rigid polymer shell which servers as an external permanent shuttering for the headwall installation. It is simply filled with the correct concrete mix to form the finished headwall in one easy visit. The lightweight unfilled polymer headwall can be easily manoeuvred on site for ease of positioning.
Live water couses do not affect the construction of the headwall because of the polymer shell, and thus the time and expense of coffer dams and pumps is completely removed.
Advantages over precast headwall units:
- The headwall's light weight (unfilled) is also advantageous where heavy lifting capabilities would be required to locate a similar sized pre cast concrete unit.
- The delivery of a heavy pre cast unit to remote areas of the construction site can require the construction of temporary road surfaces in order to provide access by vehicles capable of installation.
- The Permashutter polymer headwall can be transported in the smallest of vehicles, and delivery of concrete to the unit can be achieved easily using any suitable means to hand such as an excavator bucket or dumper.
Permashutter also hold the patent for simultaneous attachment of ancillaries to the headwall at the moment of installation.
If a handrail is required, it is simply ordered and delivered at the same time as the headwall, and is inserted into pre configured locations on the polymer shell. When the headwall is filled with concrete, the handrail becomes an integral part of the construction. No drilling and mastic type products are therefore required for the attachment of any ancillaries to the headwall. In the same way, flap valves and trash screens can also be configured and included in the one visit headwall installation.
Unique possibilities with colour finishes and textures:
The external polymer shell can be ordered in a variety of colours and finishes, these enable the headwall to either blend in with it's environment in sensitive locations, or alternatively can be brightly coloured to denote particular outfalls or chemical laden flows.
The resilient and graffiti resistant polymer shell is very Eco friendly being made of recycled plastic. Additional huge savings are made in reduced carbon emissions when comparing to the heavy transport requirements of pre cast headwall units or the multiple visits required by the cast in situ headwall.
By removing the shuttering, steel works and bending schedules required when casting a headwall in situ, along with other variables such as weather and skill of the installers, it becomes entirely feasible to construct a higher quality finished headwall unit whislt utilising the lowest possible worker skill set to do so.
The headwalls presently come in two sizes to cover pipe sizes from 200-450 mm
Easy to specify Cad drawings are available to drop into your next scheme.
Available in a range of sizes, colours and stone effects. Permashutter heavy duty polymer headwalls provide a quick and cost effective alternative to casting headwalls insitu.
Headwalls are available in the following sizes:
- HW300C - Suitable for pipe diameters: 150mm/225mm/300mm
- HW450C- Suitable for pipe diameters: 150mm/225mm/300mm/375mm/450mm
Unlike precast headwalls they are lightweight (before filling) and highly durable, being resistant to cracks, chips, algae or graffiti.
Headwalls can now be installed in a few hours complete with high quality accessories.
A full range of accessories such as handrails, pipeguards, trashscreens, anti-vermin grills, flapvalves etc. are all available.
- Handrail: Hot dipped galvanised to BS 729 after fabrication.
- Handrail Recesses: Once the mould is full the handrail can be added by inserting into the preformed recesses. (see fig. a)
- Environmental Impact: The concrete is placed into the mould through the slots shown in fig. a. Caps are fitted once the mould is filled.
- Trashscreen: Hot dip galvanised to BS 729 after fabrication. It is fixed to the headwall with BZP steel bolts, and is both hinged and lockable for easy cleaning / maintenance.(see fig c)
- Trashscreen fixing points: Bolts are inserted into pre-formed holes in the front face of the mould to anchor the pipe guard.
- Flap Valve Fixing Point: Bolts are inserted into the preformed locators to affix the flap valve(see fig. b)