# Forum Home Renovation Demolition  Demolishing a 1960s suspended concrete bathroom slab

## JonoRustyRuss

Hi, I am about to start demolishing a 2mx2m suspended concrete bathroom slab. It's around 700mm above ground. I know I will need to back prop it before I start cutting it up. Does anyone have any tips for safe/easy removal?  
Also have to remove the tile walls, which are on a concrete screed over a fine steel mesh. Any tips for removing this would also be great!

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## Bloss

What you need to do depends on a number of things - for example what is holding the slab up on its perimeter and is that slab holding anything else up above that i.e.: are there walls sitting on that slab or has it been poured in between the walls? And not sure what you mean by propping - if the demolished bits of slab are only going to drop 700mm onto the ground then why wouldn't you just let that happen then clear it all out once demolished? The slab will have steel reinforcing so you will need to have tools to cut that away - and there are a number of ways to do that. What tools do you have access to might determine how you do the job. 
It could be as simple as a decent rotary hammer drill, some masonry bits, drill a pattern of holes, bash through with a sledge hammer and keep going - but what happens at the edges, how neat that edge has to be and if there is any load bearing will change the approach. But you could also use a diamond saw, a large jack hammer - no shortage of options, but as I said you need to know what are the consequences of removing the floor before you start doing so. 
BTW - use masks, goggles/ face mask, gloves etc - safety items to fervent injury from flying material & dusts.

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## JonoRustyRuss

Thanks Bloss. This is all good stuff and I have definitely confirmed the walls sit on the frame, not the slab luckily. I am planning on cutting the slab up using a demo saw, but your suggestion of drill and sledgie is a good one. 
Reason I think I will need to prop the slab is I will be standing on it while I'm cutting it up. I am worried as I bust it up it might collapse and send me falling with it!

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## Jon

I had a similar problem many years ago and got rid of it the way Bloss said.
Drilled a series of holes through the slab down the centre line of the room and then hit it with a sledge hammer. It cracked down the row of holes and then folded in half and dropped through under the house.  Simple as.
I was standing outside the room and using the sledge hammer through the doorway for the last few hits, it gave plenty of warning that it was ready to go.

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## Bloss

In any case usually better to start in one corner furthest away from the door and work on small areas at a time. Start by getting a decent hole through - say 300x300 and that will tell you what the slab is like - how much steel etc. You will need an angle grinder to cut the steel - the small 100-115mm ones work well. Or bolt cutters if you have them - a hacksaw will do the job, but slower of course. It is possible for  slab to break away as you say, although in my experience most are overbuilt and as Jon says give plenty of warning. But a 700mm drop onto falling broken concrete would be unpleasant and dangerous so take care. For the sake of a couple of props if it is accessible might be worth doing, but so long as you do small areas at a time should be fine. Dust will be all over the place so a pump garden sprayer just to keep things damped down will be useful - make sure you have cleaned it and used fresh water - you don't want a dose of weedkiller!

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