Tree grille frames

Frames are necessary to stabilise the grilles and stop them sagging around trees. All types support the grille and retain the surrounding surface, the correct choice depends upon several factors. Frames are offered in four sections as standard. This means that both the inner and outer frame are split, ensuring that all circumstances can be accounted for. The large variety of sizes and shapes of frame has only allowed us to give examples for each weight. Frames are available for all grilles, even if not illustrated. Rimless types are made to order.

Medium duty frames
These are the most versatile type of frame, suitable up to 2000mm. They can accept bolted down segments if required and will offer good retention to block paviors. Medium duty frames will carry all tree guards, using the adjustable mounting system. These frames will accept a 6.5 tonne SMWL vehicle overrun (for occasional traffic only).
Heavy duty frames
Heavy duty frames offer full support for vehicle overrun when used with cast iron grilles. They also provide excellent resistance to side thrust for paviors, retaining the full height of block and sand base. These frames will accept a 11.5 tonne SMWL vehicle overrun (for occasional traffic only).
Rimless frames
Rimless frames can be manufactured to suit our entire range of products. These are particularly useful if you are fixing to a predetermined pit size or there are physical restraints on the size of the planting bed. The grille is designed to sit on top of the frame, so the overall size is that of the assembled castings only.

Please note that frames can be 35-40mm larger (dependant on frame type) than the stated size for the grille casting i.e. a 1200mm square grille could have a frame measuring 1235-1240mm square overall. Before designing tree pits etc. please contact out sales office for assistance. Should you wish to build the pits in advance of the delivery of grilles and frames why not ask for a template? CIS Street Furniture can provide templates for all designs of grilles and frames. A small charge may be made dependant on order.

Tree grille and frame installation

Tree grille and frame installation

Box out area to suit outside dimensions of sub-frame – grille + 35mm = frame ± 3mm.
Ensure the depth around edge has a minimum of 100mm of concrete under the angle or outer frame.
Compact sub-soil base for firm bed for concrete strip and infill with concrete (a 3:2:1 mix is advised, sulphate resisting if necessary) around the edge. Reinforce if loading requires it.
Assemble outer frame and bed frame fixings in concrete foundation. Bed in angle frame ensuring top is level and at a height to suit the surfacing.
Ensure fixings used to join angle frames are tight and pulled up to maximum torque. Re-check level.
When concrete strip has set sufficiently to hold angle frame, check tightness of inner support frame fixing bolts, ensuring they are tightened up to maximum torque to achieve optimum frame rigidity and allow concrete strip to fully cure (allow minimum 24 hrs).
Fit tree grilles, ensure that anti-vandal bolts are fitted and the nuts are applied finger tight. Sufficient space for operative’s arms should be left below the grille for anti-vandal bolt fitment.
nfill with pea gravel ensuring that the area under the inner aperture is compacted firm and free from voids and that the anti-vandal bolts are obscured from view.