CONCRETE FLOOR SLAB - SECOND POUR

In January, the second concrete floor slab was poured for the majority of the house footprint.  Using the same construction as the first floor slab, the insitu concrete floor is poured over 'EXPOL' 100mm thick EPS polystyrene insulation which is laid on top of a continuous layer of polythene.  The slab is reinforced with steel mesh, spaced off the EPS insulation boards on spacers that maintain cover to the steel mesh.  Beneath the polythene is a layer of compacted sand on top of a porous hardfill.  Pipework protrusions are made with sleeves to accommodate the necessary services (e.g. plumbing, wiring and ducting for 'Zehnder' ventilation system from Fantech, which will be installed later in the programme) for the requirements of the house design.

A portion of this slab was a suspended concrete floor using a Stahlton precast system.

Service pipes were set into the hardfill, and prepared to be cast into the slab  protruding where needed to facilitate the house services required.

At this stage, the timber framing for the walls and roof of the rear section of the house can be seen in place.  (Refer to the 'TIMBER FRAMED WALLS' and 'TIMBER FRAMED ROOF' sections of this blog for detail on these elements.)

Preparing for the concrete slab - laying pipes and spacing the reinforcing mesh.
At the rear the timber framed walls and roof trusses are visible.
Scaffolding is being crane delivered - viewed to the left of this picture.

Stahlton precast beams for the suspended concrete floor slab

Formwork around the edge of the slab is braced to support the 'Ecoblock' formork.
Reinforcing mesh is spaced up from the layer of grey insulating foam.
Grey and orange conduit for services is ready for casting into the concrete slab



Service conduit protrudes through the suspended concrete slab


 





 

Conduit protrudes through the hardfill and foundation walls 

Polythene, grey insulating foam board 
('EXPOL' 100mm thick EPS polystyrene ) 
and reinforcing mesh are laid over the compacted hardfill. 
The reinforcing bars are bent into the concrete slab.

 

 

  

This rebate is for an 11meter, fully-sealed, PH certified sliding 

glass door supplied by EcoWindows.

Base detail for the fixing of the steel portal frames is allowed
to be recessed into the concrete slab.

Viewed across the area prepared for the concrete floor slab concrete pour,
the reinforcing steel mesh can be seen lapped and spaced off the  
'EXPOL'  EPS polystyrene insulation , the reinforcing starter rods for 
the footings are bent to allow for positioning within the concrete slab,
and service conduits and drains secured.

Preparation for the concrete slab pour is completed, 

ready for the arrival of the concrete delivery.

 

 Concrete is pumped into place

 

Concrete workers move and vibrate the pumped concrete into place

 

 

 

Service pipes protrude through the wet concrete

 Concrete is float finished up to the edge formwork.

 

The concrete floor slab is then floated off.

 

 

The second concrete floor slab is complete, and left to cure. 
To the left of the slab, timber formwork has been set into the slab to 
form a rebate for the sliding glass door supplied by EcoWindows.

FLOOR SLAB - FIRST POUR

The lower level floors of the house are concrete.  'Eurosteel' reinforcing bars connect from the footings, as well as the insitu concrete walls.  The insitu concrete floors are poured over 'EXPOL' 100mm thick EPS polystyrene insulation which is laid on top of a continuous layer of polythene.  The slab is reinforced with steel mesh, spaced off the EPS  insulation boards on spacers that maintain cover to the steel mesh.  Beneath the polythene is a layer of compacted sand on top of a porous hardfill.  Pipework protrusions are made with sleeves to accommodate the necessary services (e.g. plumbing, wiring and ducting for 'Zehnder' ventilation system from Fantech, which will be installed later in the programme) for the requirements of the house design.

The sand layer beneath the polythene is screeded level. 
The black polythene can be seen,and the insulation board sitting on top. 
The 'Ecoblock' forming the edge of the slab isbraced with timber 
ready for the concrete pour.

Starter rods protrude from the adjacent concrete wall to tie into the concrete 
floor slab. The DPC can be seen turning up at the slab edges, and wall.

The sand layer is compacted

Gaps between the insulation board are 
sealed with 'Loctite'

Reinforcing mesh is spaced off the 
insulation board.The deeper level is a 
thickening in the slab.

Reinforcing steel at the intersection of thickenings in the concrete slab.  
Spacers sit on the insulation board. 

Pipes that penetrate the slab have an insulating sleeve applied, 
with a closed end to protect the pipe from concrete entry

Viewing the house from the west looking east, the lower level floor slab is being set out.  
The edge containment of the future slab can be seen by the 'Ecoblock' formwork.

The slab preparation is complete, ready for the concrete to be poured over

Once the preparation was complete, and the wet weather cleared adequately,  the concrete was  poured to form the rear floor slab.

The poured slab is kept moist to control the drying process
allowing the concrete to cure and  to minimise shrinkage cracks.