In the past electrical contractors have dissuaded their clients from using the Echo system believing that downlights were not possible when using hollow core precast floors, unless false ceilings were used. This is incorrect. Consider the following points :

• The placing of any light point into Echo hollow core floors is not only possible, but simpler and more economical than with traditional in-situ or beam and block floors, which require the positioning of concrete boxes between the steel and/or blocks. These are sometimes not only difficult to locate once the shutters are removed, but in many instances lining them up accurately is difficult.

• Fitting downlights into Echo slabs is simply a matter of coring holes through the slab, or using a chisel and hammer (we recommend chiselling from the bottom up) to form the required diameter hole to accommodate the downlight. For suspended or other light fittings, simply drill a hole through the slab and into the slab's hollow core to fit the electrical wiring through. Any excessive edge chipping is easily repaired with Rhinolite or similar material. Coring is done only once the slabs are placed into position on the building and the light positions have been marked. This results in accurately aligned lights so that false ceilings are not required. This means that there is virtually no preparation necessary, as is required before traditional in-situ or beam and block concrete is placed.

• Echo has researched the suitability of coring through slabs by drilling 7 cores and cutting through the reinforcing steel in each core. The slab was then loaded and the deflections measured over a period of time. Results were assessed by a professional civil engineer who found the slabs to be well within allowable tolerances, making coring for downlights through Echo slabs technically safe and acceptable.

• The cost per light point is also more economical. Electrical wires and single light transformers can be placed into the horizontal hollow cores of the slabs after coring. This instead of the traditional method of fitting light boxes and conduits before in-situ concrete is placed and then returning to pull wires through once shuttering and scaffolding have been removed several weeks later.

• Conduits can be laid across the slab, i.e. perpendicular to the slab direction. They must be placed onto the Echo slabs before the builder places the screed.

• Echo provide the builder with copies of the slab layout from which the layout of the wiring is easily determined by using the formed horizontal cores in the slab as conduits. This eliminates any necessity for criss-crossing conduit. Ask your builder for a copy of the layout drawing if you know that Echo slabs will be used.

• To accommodate 12 volt single light transformers into the slabs from a maintenance aspect, a minimum core diameter of 70mm is required. This will easily allow short cylindrical transformers to be taken out and replaced for maintenance. Longer transformers will require bigger diameter cores or it won't be possible to take them out. For 230 volt downlights smaller diameter cores can be used.

• Heat dissipation from the downlight globe and transformer is not a problem because the hollow core of the Echo slab has 67% more void space (per linear meter) than a conventional concrete box.

Some don’ts when working with Echo Floor slabs:

• Don't lay conduit into the V joint above the slab, unless the joint runs directly above a wall or beam. In this case however, be aware of where the expansion saw cuts will be.

• Don't glue wiring into the smaller V joint below the slab.