Ground Floor - Block & Beam

Block and beam construction is an approach to ground floors that should be more sustainable, involving blocks with recycled materials and better thermal properties than using concrete in solid floors. The completely dry construction system approach also has many on-site benefits.

Technical information

Install Block & Beam floor to the designed layout, ensuring careful placement of any detail where loading support is required. The use of aerated blocks such as H+H Celcon Standard, with their inherent thermal properties, provide a significant contribution to achieving an improved thermal performance from the floor area. Once blocks are in place the whole floor should be grouted using a 3:1 course sand and cement mix, creating a homogenous structure.

A 30mm PIR upstand should be installed around the perimeter of the floor and continued up the wall to meet the bottom of the plasterboard. Using this method will reduce the Ψ value achieved at this junction. Lay 120mm PIR insulation on top of the suspended floor with all joints taped and sealed, then finish with a layer of screed on top of a VCL. This method allows for easy installation of underfloor heating by using pipes laid on the insulation secured with proprietory retention clips.

Allow a minimum 150mm gap between the bottom of the floor beams and the ground level below. The ground below the suspended floor should be treated with weed killer prior to the installation of the beams.

How to install

This animation illustrates the Travis Perkins plc recommended installation of a new build ground floor block and B=beam with a good balance between cost of the solution and thermal efficiency, using traditional building materials. Providing a 58.75% improvement over SAP Appendix K.

Watch video

Hints & Tips

The level of the floor should be calculated before installation to ensure the finish is at the correct height below the doorway thresholds to comply with Part M of the Building Regulations.

100mm PIR insulation installed in the wall cavity below DPC will further decrease the Ψ value achieved at the junction between the floor perimeter and external wall.