House Casting Methodoloy
An example of casting a three (3) bedroom low cost house design costing.
We have multiple usage for LCM as it can be applied to making all kinds of blocks and panel ( precast), LCM can be utilize as sound-proofing materials, fire-proof materials for walls and other, foundation, slope protection, gabions, drains casting and many more. Using a system formwork, the foundation is cast and the next day, formwork is erected and cast in-place with lightweight concrete, this method makes construction of house very simple and fast, also remember that there is no need for columns and beams and not a single piece of bricks is used. There is no need for reinforcement unless it is above single storey. Raft foundation requires 1 layer of BRC.
We have also develop another system where a LCM-core system is precast and only some simple plywood is used as the formwork, LCM system allows you to used mixed of up to Grade 30 concrete to cast load-bearing walls. In the single and double storey high housing cases, LCM walling is acting as an alternative to conventional burnt clay bricks, thereby saving on wastage of precious agricultural soil and energy used in baking bricks. The technology enables reduction in dead weight, saving in cost, provides superior thermal comfort and enables much faster pace of construction. The ordinary burnt clay brick has ruled as the primary walling material for many centuries so far. Now even countries like China has ban the productions of clay-bricks.
Materials requirement and procedure for house casting
The major steps in construction are:
Materials generally need during the casting for electricity and water
- Clearing, leveling and compacting of foundation
- Assembly of nominal two way reinforcement ( BRC) with a few dowels projecting along the walls to act as starter bar for walling.
- Foundation pouring of lightweight concrete in 1800 kg/cu.m to wall base area and 1600 kg/cu.m to internal and external foundatin and finishing to plinth level
- Assembly of storey high wall forms for internal wall faces to the ceiling level or required sloping profile for the roof.
- Fixing door/window frames in position, fixing in position of relevant embedded service lines for electricity, water and fixtures like switch boxes etc.
- Assembly of appropriate external wall forms for 100mm thick walls, placing of fixtures for roofing purlins and proper alignment of total formwork.
- Pouring in-situ Lightweight Concrete in density range of 1,400-1,600 kg/cu.m.
- Demoulding of shuttering after hardening of concrete the following day and restart the same procedure for next cast.
- Fixing the roof covering, door/ window shutters, sanitary fittings, electrical fixtures, laying PVC / Tiles flooring or other wearing coat on floor, white colour skim coating of walls (no plaster needed) painting work.
100 mm UPVC sanitary outlet pre-install, 50 mm UPVC waste water outlet preinstall, 19mm Poly Pipe PN 10 water inlet and distribution pipe, 25 mm Poly PN 10 riser pipe to water tank, 13 mm UPVC Vent pipe, stopcocks and Electrical conduit with casings. Ceiling can be cast by using a thin layer of LCM and casted in between the truss of the roof. Toilet wall tiles can be inserted into formwork before casting. Generally, in terms of saving for many other application like floor tiles work, as casted LCM flooring with a high density design makes the finish level of the floor smooth enough for a thin application of adhesives mortar for the floor tile or the whole house can be PVC laid with PVC flooring.
House Detail :
Building materials require for foundation and wall casting are :
- Utilizing LCM -CORE System.
- LCM casting methods - Flat Raft Foundation
- Foundation Total 20' x 48' Inclusive car porch and perimeter drain.
- Floor Thickness 150 mm c/w 1 layer BRC - A7
- Total = 32 meter cubes. Utilizing LCM - 1800 kg/ m3 design mix for foundation and wall
- 100 mm thick with a 1500kg/m3 density mix.
- Cement 50 Kg bag x 280 bags.
- Sand - fine river sand x 3 loads.
- BRC - A7- (2.2m x 6m) x 7 pcs.
- 10 mm MS round bar x 10 pcs.
- 1" x 2" and 1" x 6" wood for foundation formwork.
- It cost around RM 4000.00 for a fast track casting of foundation and walls with the above not inclusive labour.
- Generally a low-cost house will have 7 doors and 9 windows, overall cost for Door frames, window frames and actual door and windows should be around the budget of RM 1500.00.
- Rental of system formwork for projects above 30 units should come to below RM 400.00 per unit to cast complete wall in a single day.
- Electrical and Plumbing work should cost around RM 1,500.00 Sanitary fittings and tiles for wall and floors RM 1000.00.
- Roofing truss and covering cost to be determine by type of covering and design, cost should be around RM 3,000.00.
- Skim coating and painting of house should be around RM 1,000.00.
- Total cost for LCM Foaming agent should be around RM 300.00.
Give or take a hundred here and a few hundred there it is my estimate that to built a low cost house is around RM 12,000.00 to RM 13,000.00
Much more saving can be assured from the utilization of LCM for the construction of the infra structure work as LCM is applicable for the roads, drainage and many more. It is evident that using a LCM casting methods should be much cheaper and faster to built houses.
Note : It is not practical to cast one unit as the system formwork people charges at a monthly rate of around RM 10,000.00 per month, but by utilizing LCM methods, the costly rentals can be overcome by a daily cast target. Assuming, using a single set of formwork to produce 30 casted units of complete walling for the project. Sub- contractors for electrical works and plumbing workers must be available at site during casting process. Windows and Door metal frame is special made 100 mm inserted inside formworks.
Door frames and window frames are manufacture to LCM casting methods and readily made available by many metal frames manufacturer.