Building a shed, Quantities help

steamjetjoe

Ok im planning on building a shed this summer.Its going to be under the limit for planning permission (13 x 18 internally).
Ill be laying a slab of concrete for the foundation with reinforced steel mesh, I would imaging about 6 inch deep. So how mush sand & gravel mix would I need for a foundation thats 6 inch deep & say 14 x 19 feet????

I plan to use 4'' solids. How many would I need if its 13 x 18 internally & 10 feet high???? Not including the window or door because I dont mind having a few left over.

Thanks all

slavetothegrind

for a start have the concrete delivered and decieve two mates into coming over to help barrow it. Much faster and easier all round.

Others here better able to advise on the rest!

Good luck!

steamjetjoe

joeclif wrote: »

for a start have the concrete delivered and decieve two mates into coming over to help barrow it. Much faster and easier all round.

Others here better able to advise on the rest!

Good luck!

Yeah I would need to get them out under false pretences;) I barrowed concrete before and its back braking.

I would imagine that the quantity of concrete I would need would not be worth a companies while to deliver. I have a mixer so I reckon it would be handy just to mix it myself.

slavetothegrind

Fair enough!

Just think of the quantity you need, and the amount you can mix at once, all that shovelling and stuff!

And you can bet the concrete companys are glad of any order right now!

I helped a neighbour pour a raft about twice that size, barrowed in, three barrows, all done in about an hour! Not bad!

There was four of us in fairness, but we did get a decent breakfast out of it!


.....must stop with the exclamation marks!....dammit!..doh!...aaaargh...

cork1

i reckon 12 bales of blocks. thats 528 blocks and should have half a dozen left at that. what width is your foundation?

mp22

convert your measurements for the slab to metric lenght x with x depth the answere will be in meters cubed just what concrete or gravel companies are looking for

JohnButler

agree with previous poster about converting to metric..lot of lads become pretty emotional with the mention of feet and inches!

I'll give you now a rough breakdown of what ya need...

You mention using 4" blocks so i presume you will have a cavity and two leafs of blockwork? Unless it will be lived in or anything like that your much better off using cavity blocks for sheds. Just my preference but its up to you.

Converting the size you want you slab to metric works out at 153mmx4300mmx5800mm....multiplying these tells you the area is 3.8metres. So your aswell to order 4 metres of concrete for your slab.

If you are indeed putting in a cavity then for you two leaves of blockwork all round you will need 588 4" solids. If you want to do it in cavitys then you need 294. I havent left out any for doors or windows that for the entire shell.

Hope this helps and if you have any other questions fire away.

steamjetjoe

Thanks for the advice lads, John= just thinking of what you said and ill prob go with the cavitys instead. The shed wont be lived in, just going to be a mini gym and storage for tools etc. Ill put up some of those insulated boards and then have it plastered.

Im confused as to where or when to put the damproofing down on my slab of concrete

Do I lay the plastic sheet down first and then pour the concrtet or do I pour half the concrete and then add the plastic sheet & then pour the second half of the concrete.

Joeclif- I starting to think just ordering the readymix is the best solution. Bring on the pain the next day:(

jack of all

For estimating concrete blocks- remember that 10 concrete blocks (215x 440 x relevant thickness) builds 1 sq. metre of wall. Order readymix for the base, it's quicker, easier and produces a better result. As already pointed out any of the readymix companies will be glad to deliever smaller loads now. For the base- 6- 8" of well compacted hardcore, blind with 2" sand and lay your 1200 gauge polythene, followed by your concrete base.

steamjetjoe

jack of all wrote: »

For estimating concrete blocks- remember that 10 concrete blocks (215x 440 x relevant thickness) builds 1 sq. metre of wall. Order readymix for the base, it's quicker, easier and produces a better result. As already pointed out any of the readymix companies will be glad to deliever smaller loads now. For the base- 6- 8" of well compacted hardcore, blind with 2" sand and lay your 1200 gauge polythene, followed by your concrete base.

Ok I get you. Would you recommend that I use steel mesh with the readymix?
And will a 6'' concrete slab be sufficent?

jack of all

You are effectively building your shed walls off a concrete raft, two things about rafts:

1. They are generally designed by an engineer and are site specific (I know this is only a shed) but as I am not an engineer and haven't seen the ground conditions I can only guess...As a rule though, a ground bearing floor slab will be at least 150mm (6") thick, if you want to make this a raft, supporting walls also i think you'd need 200mm (8") of concrete.

2. A raft must be reinforced, other

jack of all

You are effectively building your shed walls off a concrete raft, three things about rafts:

1. They are generally designed by an engineer and are site specific (I know this is only a shed) but as I am not an engineer and haven't seen the ground conditions I can only guess...As a rule though, a ground bearing floor slab will be at least 150mm (6") thick, if you want to make this a raft, supporting walls also i think you'd need 200mm (8") of concrete.

2. Your raft must be reinforced with steel to function properly and take the loads from the walls without cracking. Maybe an A143 mesh?

3. A specially designed "toe" detail is used around the edge of a raft for reasons of weathering (maintaining 150mm floor level above ground level, dpc placement) and taking the wall loads. I don't think you need to go down this route for a shed, unless the area is prone to flooding.

mickdw

For a small shed like this, I would go with 6" slab but thickened to about 9" around the perimeter. I wouldnt you to the bother of using cages of steel like used in a house raft as its a very small area werre are dealing with. So if you put the thicker section all the way around the outside of the building to a width of about 2 feet then reducing to the 6". I would lay a strip of mesh in the bottom of the thickened section about 2" off the ground and then a continuous mesh layer over the top about 30mm under concrete finish.

You will not mix this by hand so get readymix.