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Groundwork & Foundations

Concrete Slab for Garden Office/Workshop

Anonymous user 09/03/2024 - 3.13 PM

Hi everyone :) I am starting an exciting project to build my own garden office/workshop. I have been doing lots of research on the foundation and have settled on an insulated concrete slab - mainly to maximise head room as i will be building this through permitted development so need to keep height down to 2.5m. I just wanted to sanity check my calculations if you wouldn’t mind. I am building quite a long, thin building 2.7m x 9m (its all i could fit into the space! So far i am thinking the following build up: Hardcore - 75mm Sand - 10mm DPM Insulation board - 25mm DPM Reinforced slab - 125mm DPC I have struggled to find consistent guides on depth of slab, hardcore and sand so it would be great to understand if i am good with those depths or completely over doing it. Thanks Ned

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2 Answers

Anonymous user

Hi Ned you would definitely need to increase depth of hardcore to equal depth of slab both 125mm would be sufficient. As for sand it is not required and you would need to think of edging the concrete pad with engineering bricks and roll DPM under the pad and over the top of bricks to stop Damp rising through the pad. Hope this has helped you. Tyler sanders at TJB construction

Answered18 August 2020

e.lyon construction

Rating: 5 out of 5

Prescot

100mm hardcore sand blind 10mm dpm 1200 gauge visqueen 100mm floor insulation ( 25mm upstand round the edges) 100 mm concrete ( no need to reinforce)

Answered18 August 2020