The FastSlab Foundation System is a fast track method to construct foundations and ground floors, ideal for sites with limited access, poor ground conditions, flood plain locations and areas with tree root issues. It also works equally well in all ground conditions whilst eliminating a sometimes difficult and expensive muck shift. A typical FastSlab house foundation system can be installed within one week and is ideal for all forms of timber, LGS frame, SIPS or modular building systems.

The FastSlab foundation system uses helical steel screw piles, a LGS ring-beam, steel internal I beams, interlocking grey EPS insulation blocks and Lewis Decking for the foundation and ground floor structure. On top of this is then fitted a timber soleplate ready for the walls of the building. All this can be fitted very quickly meaning that the duration of the foundation & ground floor slab element of the build can be drastically speeded up and as such reduce costs on a project.

The geoLOGIC screw piles have a capability to carry significant loads at shallow depths to support a galvanised lattice beam ring beam, galvanised floor beams and large format EPS insulation and Lewis Deck composite floor slab. The ground floor is fully insulated and U Values of 0.16/ 0.17 are standard within the floor but can be improved to achieve 0.13 or better if required. The galvanised lattice ring beams are all manufactured to specific dimensions to eliminate waste and the standard length FastSlab floor beams are easily cut to length on site.

Floor insulation is taken care of by tightly fitting FastSlab EPS insulation blocks that sit snugly between the floor beams creating a thermally efficient sub floor ready to accept the DPM, Lewis Deck and screed. The weight of the FastSlab floor system is only a fraction of alternative PCC Block and Beam systems and can be installed without any heavy lifting equipment.

FastSlab Foundation Literature

  • Works with all ground conditions
  • Cost effective
  • No heavy lifting equipment needed
  • Fast & easy to install
  • Reduces time on site
  • High thermal performance
  • Efficient underfloor heating system
  • No excavation

The FastSlab Foundation system was the perfect solution to my site where the number of trees and roots meant I wasn't able to use a traditional foundation system. The speed of the installation also meant I could bring the timber frame in early than originally planned too.

Liz Galpin

The FastSlab Foundation system is suitable for all types of ground conditions however it comes into it’s own when dealing with unusual site conditions such as tree root issues, difficult site access, high water table, contaminated ground etc.

Steel Screw-piles, steel lattice ring-beam, steel internal beams and expanded polystyrene (EPS) insulation blocks with the Lewis Deck over the top
Steel Screw-piles, steel lattice ring-beam, steel internal beams and expanded polystyrene (EPS) insulation blocks with the Lewis Deck over the top


We have an experienced design team that can tailor the foundation design to suit your specific site needs. Please give us a call to discuss your requirements or if you need any further information.


Ask CDI a Question

  • Q

    What are the Lewis Deck sheet sizes?


    Q: What sheet sizes are held in stock for delivery within a few days after order? A: We stock 2500mm and 1300mm sheets.  These are all 630mm wide and 16mm deep.  Deliveries are made via the pallet network directly to site.  The smaller sheets are aimed at small bathroom renovation projects and can be supplied in small numbers via TNT. 2.5* and 1.3m sheets allow for the 100mm overlap to occur over a joist, with joist centres being either 300mm, 400mm, 600mm, 800mm*, 1200mm and 2400mm*. (*2.5m sheet only) For larger projects we are able to produce bespoke sheet sizes if required, please get in contact to discuss other options for sheet sizes.


    Lacomet – How come it has no scrap value?


    Lacomet – How come it has no scrap value? Many of the projects that we get involved in starts with a phone call or email to us from someone researching replacing stolen leadwork. Many of these are old buildings, such as schools or churches, where this isn’t the first time that the lead has been stolen and they call us fed up with having to replace it again full in the knowledge that they will more than likely go through the same problem once more in the near future if they continue to use lead. One of the big benefits that Lacomet FL brings to a project is the fact that it has no scrap value and therefore the chances of it being stolen are massively reduced. Due to the 2 thin aluminium layers, and its five layer total construction, it is of no value to thieves. Lacomet can be recycled but the polyester based coating would need to be de-laminated first and the amount of recovered aluminum is then very low, in fact it would be easier and more profitable to collect empty drinks cans than to mess about stripping Lacomet down. We can also supply stickers that can be placed in strategic locations informing people that what is now on the roof is not lead and that it has no scrap value.

  • Q

    Why don't my Lewis sheets interlock like they do in the video?


    Q: Why don't my sheets interlock like they do in the video? A: The sheets have two sides (one printed, one plain), the dovetails on either side are different widths, it is then necessary to alternate the sheets print up and then print down.


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