Browse Forums General Discussion 1 Nov 01, 2010 12:59 pm Hi Can anyone tell me if it is possible to install a basement under a concrete slab floor (I have a single-storey two bedroom townhouse). Is it possible to cut a hole in the slab then excavate a chamber under the slab? Or would this destroy the integrity of the slab? My plan is to dig down under the slab then hollow out a space about 5m x 5m x 2m high (which would sit completely inside the existing slab borders). I would then lay a concrete floor in the basement, build walls using cinder-blocks, then use RSJs to support the ceiling. Is this just a dream...? Cheers Installing a basement under a concrete slab floor 2Nov 01, 2010 1:41 pm I think it's a dream unless you can secure such building permit as well as the cost of re-footing the perimeter of your house. To install a basement the load bearing footprint of your home will need underpinned footings. These will need to go deeper than the basement. So you are not looking at just cutting into your slab. You are looking at an excavation exercise and lots of concrete pumping. This would be a $100k plus exercise. Re: Installing a basement under a concrete slab floor 3Nov 01, 2010 5:31 pm Provided your foundations are suitable and you can get a permit, it would be cheaper to go up another storey than try and dig out a basement. It is hellishly expensive and not to mention you will need to relocate your services which come up through your slab. Re: Installing a basement under a concrete slab floor 4Nov 01, 2010 11:05 pm Its an interesting proposition. I really have no idea if its viable but would be possible. I just installed a cellar in my new house before the slab and footings. The slab cutting should be the least of your problems. Footings are the concern, going near footings could be expensive. The reason why builders would charge so much because of the chance for something to go wrong. I have seen excavation under a concrete slab from the front or side or back of the house. Yes lots of prop supports. Anyway speak to an engineer. Obviously it would be cheaper to go up. Good Luck Pulpo DIY, Home Maintenance & Repair to do it properly you need to dig out the garden and waterproof the outside of the wall. There are some products you can put on the face of the bricks but the water is… 2 2386 Hello - we were hoping to apply laminate click lock panels to our concrete ceiling, but not too sure how to go about attaching the panels to the concrete. Any idea what… 0 691 Thanks for the insights, that makes perfect sense, and yeah, I will be leaning on the experience of the excavator operator entirely. 6 11049 |