# Gym Shed Concrete Base



## fishpat86 (29 Jan 2014)

Hello all,

I plan to build a 9' x 12' shed this summer to use as my home gym. Someone suggested using thick paving slabs for the floor but I don't think they would last having 150kg plus dropped on them occasionally. Would paving slabs work ok or do I need to go with a concrete base and if I do, do I have to use hardcore underneath the concrete?

Pat.


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## MARK.B. (29 Jan 2014)

Paving slabs will crack quite easily when you drop weights on them. imho if you put a concrete base in you will most definitely require a decent sub base ,i believe that type 2 crushed chalk is used in preference to old bricks etc,but as its a shed i guess old brick etc would be ok.You will need to cover your hardcore with a layer of sand(blinding ?) and compact this down before installing a DPM (damp proof membrane) and then your concrete on top . 
Not a builder but thats how i would do it and i'm sure one of our friendly members will be along and will give you better advice if i'm wrong. 

Ohh yes welcome to the site.


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## carlb40 (29 Jan 2014)

That sounds about right Mark, i would also have some insulation before laying the concrete - if spending any length of time in there.


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## fishpat86 (29 Jan 2014)

How thick a layer of old bricks or chalk do I need? Also, insulation is not an issue. I currently train in my single car garage that is in a block. The coldest it has been in there is minus 5c and I soon warmed up.


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## MARK.B. (29 Jan 2014)

I would think about 4" would be plenty and as for the insulation you might as well put it in now as wish you had at a later date.


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## powertools (29 Jan 2014)

Slabs will crack. The reason I know this is a while ago I spent several days laying a patio area in the garden and when finished I wanted to place a 150kg old anvil on a tree trunk 18" high I did this with an engine crane with a makeshift sling and about 12" off the ground the sling gave way and the anvil hit the floor cracking 3 slabs in the process.
Maybe you could pop round and lift it on to the trunk for me.


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## cambournepete (30 Jan 2014)

As youre doing this yourself I'd be tempted to put a layer of rubber down and a wooden floor on top of that...


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## DMF (30 Jan 2014)

Hi don't know if it's any use but helped a mate out converting his garage into a gym, I take it your using cast weights? If so then sprung timber floor or rubber covering anyway if there's a chance of dropping them, they can crack easily by all accounts and he said the free weights bit at his gym had it down.

Dean


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## MMUK (30 Jan 2014)

Personally I would dig a perimeter trench about 16" deep and spade width. Concrete this up and level all round. Then lay 3 courses of Class B engineering bricks (giving you a wall height of approx 9"). Once the motrar has cured (a couple of days in current weather) level out the inside and blind with building sand and fit a DPM, making sure that the DPM has plenty of overhang on the brickwork to allow for it to pull down once the concrete is poured in. Then I would lay in 75mm polystyrene sheets and concrete over, giving you a concrete depth of around 6".


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## Joe Shmoe (30 Jan 2014)

If you want to do things properly, go onto pavingexpert.co.uk and read up on how to lay a garage base rather than a shed base, seeing as you'll be having quite a bit of weight dropped about. If you're lazy, make a big square the size of your shed out of 2x4 timber and fill it with concrete, perhaps put a sheet of A142 mesh in... .. I'm sure it will suffice, it's a home gym not anything special. 

For my Gym, I have ex-commercial playground rubber matting, which is 50mm thick or so, and handles large Dumbbells being dropped with ease. You can buy new for £50 a mat or sometimes they are second hand on eBay etc. Don't bother with the normal gym flooring or mats you get on fitness websites, they are rubbish and twice the price of playground matting.


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