SPECIFICATION
Nidagravel is a 100% permeable paving platform that is both environmentally friendly and human friendly.
Nidagravel is ADA compliant for pedestrian, handicap, and bicycle uses. Nidagravel qualifies for many LEED credits and meets BMP Storm Water Criteria and Low Impact Development.
Our range of Nidagravel gravel stabilizers are tried and tested in almost every application and can be relied upon to provide a long term, stable, and permeable gravel surface. The Nidagravel range includes four different products... Nidagravel 129, 130, 140 & XHD.
Each product in the range will stabilize gravel effectively and each product is suitable for a variety applications. The area, loading and intended use of your gravel surface will determine the choice of product. All products can be used for small and large projects, both commercial and non-commercial as all products in the range are multi-purpose with a range of benefits depending on the application.
SUMMARY OF PRODUCT APPLICATIONS:
Nidagravel 129 - lightweight use (pathways, patios, roof gardens, and tight spaces)
Nidagravel 130 - medium weight use (driveways, public pathways & plazas)
Nidagravel 140 - heavy weight use (Car parking, heavier use driveways & public space)
Nidagravel XHD - extra heavy weight use (Industrial and commercial areas)
SPECIFYING THE FILL MATERIAL:
For Nidagravel 129, 130, and 140 we recommend using a hard, angular decorative aggregate with an average maximum size of 3/8” in diameter. This nominal size aggregate can contain smaller sizes, but ideally not larger.
There are two main reasons for this fill specification, firstly this size aggregate settles and compacts well into the individual 1.93” diameter hexagonal cells of the honeycomb panels providing a solid, stable platform. Secondly, the stabilization panels are designed to be hidden and this size of aggregate allows for a 3/8”-5/8” surface layer of aggregate to cover the sheets making them invisible. The finished surface dressing also allows for any torsion forces applied to the surface, ensuring optimum performance and lifespan of the gravel stabilization system.
Nidagravel XHD is a different type of gravel stabilizer to Nidagravel 129, 130 and 140. The XHD is designed for heavy duty, commercial and industrial applications. It has thicker cell walls, will accept a larger aggregate size and is intended to be visible when filled. The fill specification for Nidagravel XHD is the same as Nidagravel 129, 130 and 140, but with decorative aggregates up to 3/4” in size.
SPECIFYING THE SUB-BASE MATERIAL:
An assessment of the sub-grade should also be made and the surface of the sub-grade material should be prepared according best regional requirements and practices. Nidagravel products do not replace any part of the sub-base build up and are designed to stabilize the gravel surface only.
The honeycomb cell structure of Nidagravel 129, 130, 140 and the matrix structure of XHD reinforces the gravel infill and transfers vertical loads from the surface, distributing them over a wider area. Nidagravel products have very high compressive strengths when filled, from 300 to 400 tons per sqare yard, depending on the product. These high compressive strength allows the products to be specified for commercial and industrial use or applications where heavy axle weights are applied to the surface. It is important for specifiers to ensure the sub-base thickness is designed to meet the hydraulic and loading factors of the application.
Where Nidagravel products are to be used as a full infiltration, part infiltration or zero infiltration layer to a Sustainable Low Impact Development (L.I.D.) then the guidelines for permeable sub-bases should be applied.
SPECIFYING THE INSTALLATION:
All Nidagravel stabilizers are designed to be laid on top of the appropriate sub-base for the application and loading. A 3/8” - 5/8” layer of sharp or grit sand should be used to blind the surface of the sub-base and provide a thin bedding layer for the Nidagravel panels. Nidagravel 129, 130 and 140 honeycomb gravel stabilizers have an overlap of membrane along one short edge and one long edge. Once the first sheet is laid these overlaps of membrane are folded out and the next sheet is placed on top and butted up to the previous sheet.
No mechanical fixings are required as the weight of the gravel fill is more than sufficient to hold the sheets in place. We recommend laying full sheets across the flow of traffic in a running bond pattern to stagger the joints, but where the site does not permit or it is not economical to do so, other layouts can be used without detrimental effect. Where possible full sheet sizes should always be used in high use areas, such the entry to a driveway. Off cuts can be utilized, to minimize wastage on site, but these should be kept to a reasonable minimum size and be used towards the edge of low use areas. The honeycomb sheets can be cut to fit any shape required including curves and acute angles.
It is best to cut Nidagravel sheets using an electric angle grinder or circular saw for a clean cut. Standard cutting discs can be used including diamond grit masonry discs. Sheets can also be cut with a fine toothed handsaw. It is important to note that Nidagravel achieves its full strength when filled and no mobile loads should be moved onto the sheets until filled.
SPECIFYING THE GRAVEL FILL & FILLING THE SHEETS:
We recommend using any decorative aggregate with an average size of 3/8” to fill Nidagravel 129, 130 and 140. There are several reasons for this specification, firstly this size of gravel fills the 49mm diameter honeycombs cells perfectly and compacts well with minimal voids. The compacted gravel within the honeycomb cells gives the Nidagravel sheets their full load capacity.
It is generally acknowledge that the characteristics of more angular gravels or decorative chippings can bed down or compact a little better than more rounded gravels due to their shape and the use of a harder stone, such as granite, quartz, basalt, or similar. Softer calciferous stones, while able to work, will degrade over time, lowering the lifetime expectation of the surface.
Nidagravel is designed to be an invisible gravel stabilizer and to achieve this, during installation, the sheets should be overfilled by approx 3/4” of gravel. This can best achieved by using a gravel with an average size of 3/8”.
Approximately 4 - 6 weeks after installation the gravel overfill will have naturally settled into the honeycomb cells and have been compacted by vehicle and pedestrian traffic to leave approx surface layer of gravel. This settlement / compaction process can also be accomplished as a last stage process by compacting the gravel overfill with a plate compactor or wake plate at the end of the installation.
SPECIFYING THE MAINTENANCE ROUTINE:
This is a simple area to specify as the product range requires very little maintenance after installation, making the Nidagravel product line a very low ongoing cost factor when considering material selections for your clients. We would recommend that in addition to standard maintenance of external surfaces, that an inspection of the surface is carried out twice a year, to ensure that the honeycomb cells of Nidagravel 129, 130 and 140 are covered with a 3/8” - 5/8” layer of gravel.
This simple visual inspection is quick to complete and where necessary more gravel can be added and leveled as required to maintain the surface layer. This maintenance routine will insure a long term performance of the Nidagravel panels.
