Another shed build..

[Welderpaul]

Slabs laid on sand is the way forward. Or is it also a base for a motorway flyover?

 

[Ratty]

Mornin Si, I know I'm starting to wonder myself! My neighbour has two sheds (albeit, smallish ones) almost touching each other and sitting on bits of 4x4...been there for years. Mind you I did notice water running down in the gap the other day so they'll probably be rotten before too long.
I don't want a wooden floor in this shed, it needs to be good concrete for wheeling large containers in and out that may be full of liquid.
My walk-in freezer is sat on a steel base full of shingle and hasn't moved a mm in many years.
Still....I can weigh up the options, no harm in that. Weigh 'em up...then plough ahead regardless

 

[Ratty]

Slabs laid on sand is the way forward. Or is it also a base for a motorway flyover?

How did you guess?
No it really does have to be concrete but it's not a garage, maybe some of the advice being given is thinking cars but even my wheelie swimming tubs won't be that heavy.

 

[Drains]

for wheeling large containers in and out that may be full of liquid.

Just liquid?

 

[Ratty]

Just liquid?

Well...obviously no but this isn't the forum to discuss the contents

 

[Ratty]

Here's a question; farmer has said I can help myself to crushed concrete which sounds great in principle but the site is about 4 miles away and it will mean loading a trailer by hand - and paying someone to help (I no longer have the arm or back strength ). Is it worth it?
I really want to get on with this shed but we have another to build, a bigger one so I'm trying to decide the wisdom of getting a lorry load dumped that will do both pads or just getting enough to get on with this one (a lorry load will be a big pile of stuff to have in the way).

With the stuff I've already got I reckon I only need about another cubic metre

 

[snowcat]

crushed is about 15ish a ton, iv screwed down to 6-7 on large amounts, but unless you can collect you are going to be shafted on the haulage for anything under a load..

Id agree on the reinforcing being way Ott put down slabs in barns designed to have Artics on them with only reinforcing layed in strategic places..

4" and a half decent job on the prep is more than enougth.......

 

[Mikey D]

Dont forget the dpm ,worth it for the price of a roll £30 or so .
hire a wacker plate for a day to compact the hardcore ,then 100mm /4" concrete jobs a goodun .
Obviously wait for a few days of frost free weather
oh and add on about 10% when you work out the amount of concrete

cheers mike

 

[Drains]

For the quantity of hardcore you need Rats, it might be worth getting it in 1m cube bags (don't take my word for it) - much lower delivery charge from the builder's merchant, and not a dirty great pile o' aggregate all over the shop.

 

[Ratty]

Id agree on the reinforcing being way Ott put down slabs in barns designed to have Artics on them with only reinforcing layed in strategic places..

Righto - sounds good to me and will save a good few pennies. Cheers Snowy

Dont forget the dpm ,worth it for the price of a roll £30 or so .
hire a wacker plate for a day to compact the hardcore

Already have the dpm and deffo a wacker plate (see below)

For the quantity of hardcore you need Rats, it might be worth getting it in 1m cube bags (don't take my word for it) - much lower delivery charge from the builder's merchant, and not a dirty great pile o' aggregate all over the shop.

Think I've sorted the aggregate side and will get a load delivered. I had a look at the site for the other shed - for the ratman's gardening/woods stuff (tools and machinery...approx 20' x 12'...bigger if ratman isn't looking ) Whilst it was going to be a majorish job sorting the plot (removing tree stumps and levelling) I realised I could easily move the chestnut fence and re-route the track between two different trees and not only create a better space but may even be able to persuade the truck to drop the aggregate much closer to the site (and out of the way of the drive).
The weather (and Christmas ) may stop play for a while but if we can get the second site prepared next week we can get a wacker in to compact both areas. The second shed may end up being a pre-fab, this doesn't look too bad except for the annoying bar across the threshold which will have to go or the chipper will be a pig to get in and out.
His and Hers sheds
Just got to work out how much aggregate to get and try and get it delivered before the world shuts down.

 

[scarecrow]

if the slab is less than 13 or 14 ft. wide you should have no trouble in tamping it in one run and there is no need for reinforcing unless the ground is very bad. make sure you get off all the topsoil and it should be fine

 

[Ratty]

Hi sc slab is nearly 16.5' x 11.5' and would have to be tamped lengthways..reckon we can do it in one? I have a good length of 6x2".....

 

[mike os]

easy....well easy as in you can do it

 

[Ratty]

thought you were going to say 'eeeeasy cowboy'

 

[scarecrow]

your shed shouldn't stop you from pouring on the 11.5 run you just need to fill your footprint as you go

 

[Ratty]

your shed shouldn't stop you from pouring on the 11.5 run you just need to fill your footprint as you go

sorry - being a bit dim...I don't understand

 

[scarecrow]

sorry - being a bit dim...I don't understand

it could be me im more than capable of confusing myself sometimes
I presume you're thinking of tamping if from right to left you can also tamp from the back to the front you just have to stand in the cement on the shed side
tamp a little take a step fill your footprint shouldn't take much more than a couple of metres concrete
make sure to have a bit dug away in front of where the door is going so if there is any leftover you have somewhere to put it

 

[Pete.]

Ratty I poured a 4" 12'x15' un-reinforced slab over a DPM straight onto the dirt. My ground is quite hard though being in a chalk area, but it's held up fine, no cracks even under my mill and lathe which are right next to each other. I used a darby to get a decent level and troweled a finish onto it, then a gallon of floor paint to keep the dust down.

I used one expansion joint across the middle. Important thing is to keep out moisture (DPM) and avoid wide swings of temperature inside by having the workshop insulated. This will also save it from getting uncomfortably hot inside in summer.

 

[Ratty]

Thanks Pete, that's very helpful information. I'll need to put down hardcore tho' as the ground used to be a garden and there is still very soft topsoil which needs removing so it looks like it will be 4" hardcore compacted, blinded with sand, dpm and 4" concrete.
Scarecrow - thanks, I get it now ,the problem was that there is nothing on the old shed side to tamp against (unless I screwed a batten to the existing slab) but as I've decided on advice to do it in two hits with an expansion joint that solves the problem.

 

[pidgeon chit welder]

There is a nifty bit of small plant hire that is called a magi-float ( Or magicfloat ). It runs on a small petrol engine and floats above the concrete as the float bar is specially shaped & hollow enough to float the whole machine . My base was 5 mtrs by 6.5 mtr of 150 mm bridge building spec concrete on a a jointed engineering poly sheet 1 mm thick over a barely settled live when wet silt garden.

Currently ....There are no cracks or movement in the monolith slab .. it supports some five tonnes across the whole area.

Providing you can locate a working one you could easily do a complete pour of slightly wetter than normal mix .
Wearing watertight wellies you walk over the rough raked out concrete with the magcifloat , starting at one end and use it like a hover mower side to side and back and forth working your way backwards leaving the finished concrete infront of you , it will tamp and screed in one finish as smooth as any powerfloated job for it oscillates the beam like a vibrating poker. It brings all the finings up to the top and then settles them like a steel troweling would .
Time wise it took about an hour to do both the inital floating and do a second finings floating on my base.

It's worth thinking of IMHO especially if you can see someone use it to give you the visual method of using it...
The one I hired two years ago cost £38 for a days hire and arrived just before the ready mix lorry.( thankfully )

It is so light to use you would find it amazing.. I have major upper & lower back and both shoulder joint problems and thought it was an absloute breeze to use it by myself .