We are building a small front extension and have had to go down the piled/ground beam foundation route due to the clay soil and the proximity of trees with building control. The piles and ground beam are now in so I'm now finalizing the ground floor design.
Building control have now also asked us to incorporate anti-heave in the ground floor design, so I'm looking at using 160mm 7/10 Cellcore HX S to incorporate this requirement and provide the base for the concrete slab.
The slab area is approximately 2.3m x 5.3m and will need to connect in to the existing house walls on two sides.
My plan is to drill and resin fix rebar at 200mm centers into the outer leaf of the existing walls and the inner leaf of the new extension walls. The bottom of the slab will be on the inner edge of the ground beam with the rebar support in the new wall half way between two courses of engineering bricks.
A142 mesh will then be tied into the perimeter rebar supports.
My questions are?
How to incorporate the DPM, current design is above the slab before the insulation layer?
Diameter and length of rebar to use to tie into the existing walls?
Given the slab is sitting on a compressible layer of anti-heave material, would incorporating T12 or T16 rebar at set intervals across the width of the slab tied into the walls either side provide a better solution or will the A142 mesh on its own be okay?
I've included a couple of diagrams below showing the proposed section and foundation plan.
Any guidance or suggestions appreciated.
Building control have now also asked us to incorporate anti-heave in the ground floor design, so I'm looking at using 160mm 7/10 Cellcore HX S to incorporate this requirement and provide the base for the concrete slab.
The slab area is approximately 2.3m x 5.3m and will need to connect in to the existing house walls on two sides.
My plan is to drill and resin fix rebar at 200mm centers into the outer leaf of the existing walls and the inner leaf of the new extension walls. The bottom of the slab will be on the inner edge of the ground beam with the rebar support in the new wall half way between two courses of engineering bricks.
A142 mesh will then be tied into the perimeter rebar supports.
My questions are?
How to incorporate the DPM, current design is above the slab before the insulation layer?
Diameter and length of rebar to use to tie into the existing walls?
Given the slab is sitting on a compressible layer of anti-heave material, would incorporating T12 or T16 rebar at set intervals across the width of the slab tied into the walls either side provide a better solution or will the A142 mesh on its own be okay?
I've included a couple of diagrams below showing the proposed section and foundation plan.
Any guidance or suggestions appreciated.
