Full Structural Engineering Service Available
Structural Engineering for Domestic Residences and Home Units Commercial Office Buildings, Public Buildings and Industrial Buildings. Civil Engineering Designs for Retaining Walls, Storm water Drainage Systems.
We can design your concrete floor slabs:
- Concrete Raft Floor Slab
- Concrete Suspended Floor Slab (all types)
- Concrete Floor Slab on Ground
- Concrete Foundations & Concrete Pier Pads
- Concrete Structural Beams
We can design your steel structural components:
- Steel Portal Frame
- Steel Universal Beams (UB)
- Steel Column
- Steel Roofing Structure
- Steel Roof Decking
- Steel Base Plates and Anchor
- Steel Bracing
All structural engineering designs are certified by our Business Associates: Practicing Structural Engineers
- Kneebone, Beretta & Hall P/L
- Mr T. Hall (F.l.E. Aust CPEng)
RAFT SLAB REQUIREMENTS
Level the area as much as possible, where the proposed floor slab will be situated by excavation, scraping etc. Dig the edge beam at the perimeter of the proposed slab at a minimum of 500mm deep and 300mm wide. Clean out the edge beam trenches, no residue soil or fill to be in the edge beam trenches. Pour 50mm of clean fill or sand under the proposed floor slab as a base (floor slab only…not trenches and beams) Spread the polythene (plastic) black or orange blanket over the proposed floor and trench area. Do the same with the floor slab beams as shown on the engineers’ drawings. Floor slab beams are 500mm deep and 300mm wide with an 45degree up angle, see engineers drawings.
Built the concrete slab timber formwork around the perimeter of the concrete slab. Make sure the thickness of the concrete floor slab is according to the structural engineering drawings. In most cases the floor thickness is 100mm or 120mm (check the engineers’ drawings).
Prepare the trench mesh that will fill in the edge beam trenches. Tie with trench mesh wire the layers of trench mesh (top & bottom) as approved by the structural engineers’ drawings. In between the trench mesh layers (top & bottom) tie down the tie bars at nominated centres’ with tie wires.
Place the steel mesh support chairs in the edge beam trenches to support the two layers of trench mesh and tie bars as per engineer’s drawings. Make sure there is a clear space top and bottom of at least 20mm from the bottom and top of the edge beam trenches, the trench mesh should be in the centre of the trenches with the concrete surrounding the mesh.
This is also required for the floor slab beams, these are beams in the floor slab at a 6.0m centres see engineers drawing.
Check the engineers’ drawings for the specification of the floor mesh or fabric. The floor mesh is specified as SL 72, 82 or 92 depending on the size or use of the proposed concrete floor. Place the steel support bar chairs on the floor area as per engineers’ specification or drawing. Place the floor mesh on the support bar chairs, tie the floor mesh to the next floor mesh to fully cover the slab with the floor mesh from end to end. The floor mesh should overlap over the installed trench mesh as per engineers’ drawings. Make sure the floor and trench mesh are in position and tied down by tie wire. The floor slab mesh should overlap the next floor mesh with a minimum of 450mm to provide an uninterrupted top layer of floor mesh over the entire concrete floor.
At this stage when the steel mesh and trench mesh are in position, call in for a steel inspection by either the local council or structural engineer, to approve the steel in position stage before the pouring of concrete. Make sure that the steel inspection is approved by the council or structural engineer before ordering the concrete to be poured to form the floor slab with the edge and floor slab beams in position.
RAFT SLAB NOTES:
- Characteristic concrete compressive strength (F’c) in accordance with AS. 3600 to be 32Mpa.
- Maximum slump to be 80mm.
- Concrete in slab to be mechanically vibrated during placing.
- Cure concrete by keeping constantly damp for at least 5 days after placing.
- Reinforcement to be supported on bar chairs spaced at every 5thwire in both directions.
- Grade finished ground surface to divert water away from slab on all sides and to prevent ponding.
- Install “TERMI MESH” or “Kordon” blanket strip or similar termite protection system as per manufacturers’ specifications on the slab as shown on the manufacturers’ brochures and drawings.
DO NOT USE RUSTED MESH AND/OR TWISTED REINFORCEMENT RODS……!
ALWAYS USE “FRESH/CLEAN” FACTORY SUPPLIED MESH AND REINFORCEMENT RODS, RUSTED METAL IN CONCRETE CAUSE “CONCRETE CANCER” THIS WILL CAUSE THE CONCRETE SLAB TO FAIL /COLLAPSE.
Concrete Floor Slabs
As a guide only (minimum to maximum price range). All pricing is in Australian Dollars (AUD).
|Concrete Floor Slab||Concrete Raft Floor Slab (plan & details) design drawing @ $7.50 per Sq M||$|
|Concrete Waffle Slab||We do not design/draw waffle slabs (Polystyrene is not a construction product)||N/A|
|Structural Steel Portal Frame||(plan & details)||On Application|
|Concrete Suspended Floor Slab||Concrete Suspended Floor Slab (plan & details) @ $ 10.50 per Sq M||$|
|Foundations & Footings||Foundations & Footings (plan & details) @ $ 9.00 per Sq M||$|
|Structural supporting Beams||Structural supporting Beams (plan & details) @ $ 8.00 per Sq M||$|
|Structural Engineering Certification and/or Hard Copies||Structural Engineers Certificate & Specifications||$650|
|Drawing & Document Printing|