# base for wooden shed



## carocris (4 Dec 2008)

I was thinking of getting a wooden garden shed 12x10 or 12x8, is it a reasonable idea to sit the shed on say battons of 4x4 which just lie on the earth or wood i definitely need to put some kind of concrete base down?


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## yetloh (4 Dec 2008)

Can't understand why no one has replied. 

I wouldn't put bearers on bare earth - they will surely rot even if treated and putting the problem right will be much tougher than doing something better in the first place. If you have big trees very close by whose roots could push up your base, nothing less than a substantial concrete slab will do. Otherwise, ordinary cheap paving slabs laid on a couple of inches of gravel will be fine. You might want to block off the spaces between the bearers so that rats can't make a nice cosy home there. I reckon 3x2 inches would be ample. 

Hope this helps.


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## yetloh (4 Dec 2008)

Sorry should have added place them about 15inches apart.


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## carocris (4 Dec 2008)

What if i used say oak and put a layer of polythene between the wood and soil? And would you go for paving the whole area of the shed or could you get away with say three strips of slab, two on the outer edges and one down the middle? Thanks.


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## joiner_sim (4 Dec 2008)

For a shed, I would definatley put down a completley slabbed area underneath. My mini workshop is a shed and lies on top of a slabbed base, with small bearers providing a gap.

I think I've heard people on here saying that if you are going to build one as a workshop, a damp proof course is advisable. I may be wrong though.


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## MikeG. (4 Dec 2008)

Sorry, I didn't spot the post......

A piece of plastic sitting on the earth is completely pointless! Indeed, it could be worse than useless, actually holding dampness against the timber. There is a much better case to be made for sitting timber bearers on some crushed hardcore, shingle or granite chippings .....anything to raise the timber off the earth and to allow moisture away and air to circulate.

Having said that, I would try and do the job properly, with a concrete base and two-course brick plinth, then a DPC and then plant your shed walls on top of that. The concrete should have a DPM under it, and be cast such that the top is a couple of inches above finished ground level.

I wonder if I should write "Mike's Definitive Guide to Shed Building" and post it somewhere obvious before I get accused of being too repetitive?

Mike


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## carocris (4 Dec 2008)

Thanks. Any ideas on cost of materials for building a 12x10. I would probably go for tongue and groove, looks good. I've been warned off buying one of these flat pack sheds, has anyone experienced one?


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## MikeG. (4 Dec 2008)

No idea of costs I'm afraid......but doing it properly won't cost you all your tools rusting or getting chewed by vermin, and you don't have to allow for building it all over again in 3 or 4 years time!

T&G? Do you mean for cladding the outside?

Mike


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## carocris (4 Dec 2008)

Yeah T&G for the outside. Do you know what sort of size requires planning regs? i'm sure 12x10 is probably within limits. Sorry for making you go over old ground, i'm new to this forum.

I think i'm just trying to get away with doing the minimum work on a shed because i only rent the property, so i'm trying not to go to town on it. But i guess it can always be made to be dismantled. Do you have any ideas for skylights in the roof, the more natural light the better?

Once again thanks for your time.


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## MikeG. (4 Dec 2008)

There are two different sets of rules you need to comply with...........Planning Permission is one, Building Regulations is the other. 

Planning Permission is whether you are allowed the building on not, and what it should look like (essentially). Building Regulations is the technical specifications you are required to adhere to in building it.

So long as you keep this in your back garden and away from a boundary you won't need either PP or BR Approval (so long as you aren't in a National Park or other designated area). You must keep the ridge below 4m, or if it is a flat roof, keep that below 3m.

I would recommend feather-edge boards rather than T&G. FE is much cheaper, and is designed for the job.

Mike


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## carocris (4 Dec 2008)

Thanks Mike.


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## filsgreen (5 Dec 2008)

Mike Garnham":2log8suw said:


> I wonder if I should write "Mike's Definitive Guide to Shed Building" and post it somewhere obvious before I get accused of being too repetitive?
> 
> Mike




Maybe a stickey at the top of this topic would be a good idea Mike?


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## mailee (5 Dec 2008)

I don't know if it will be of any help to you Carocris but I have recently built a shed using CLS and shiplap of 10'x8' and the cost was a little under £500 for the timber. HTH :wink:


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## Shultzy (5 Dec 2008)

carocris, there are a number of shed builds in this section with different bases, do a search. The cheapest is probably plinth construction, followed by slabbing, then solid concrete. Any of these methods will provide a level surface to build your shed, which is essential for a workshop. Check out my workshop build if you go with a slabbed solution.


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## gedereco (10 Dec 2008)

HI, sorry i'm a bit late on this but i work in groundworks usually do bases for houses ans large industrial buildings. I would recommend you put it on a 150mm slab if you work it out a shed comes out at about 1.8 meter cubed. If you get Gen 1 spec you could get a mini mix to deliver just watch they don't charge you for waiting time and mt space in truck. it cost around £80 plus vat a meter . If you want to mix it yourself it works out about 2 tonne a meter cubed and for each tonne of aggregate you'll need 10 bags of cement .Usually takes two of us about an hour todo 40 mixes and float finishing for a base that size. I would recommend putting a concrete base down as it is a pain to move a shed when it's full of tools also put dpm membrane(polythene 1200 guage ) underneath to stop frost cracking slab and damp rising as concrete is very porous.
hope this helps. dont forget you'll need hardcore underneath then about a 1" of sand to lay membrane on...


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## Rich (10 Dec 2008)

carocris":2panx4lj said:


> I was thinking of getting a wooden garden shed 12x10 or 12x8, is it a reasonable idea to sit the shed on say battons of 4x4 which just lie on the earth or wood i definitely need to put some kind of concrete base down?


Hi Carocris, I purchased a 12x10 h/d workshop/shed in flatback mode with heavy duty flooring, for the base I dug out the space and laid a raft of con blocks on their sides about 100mm bigger all round, a rectantangle with 2 rows across the 10ft width equally spaced, the outside was two courses whilst the two cross rows were single, I laid 2 4x4 treated posts on these, dpc under, after leaving for a week, the shed went up in about 2 1/2 hours, it can be done on your own with a long length of 4x2 and some 3" screws, I left the roof felting till the next day, btw, a dpc was laid on all bearing surfaces and weed proof membrane was laid with sand on top of that, the 4x4's allow a little bit of forgiveness in the floor, which I covered in 18mm t/g loft board, traversing the h/d floorboards. hth.

Rich.


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## Escudo (10 Dec 2008)

> Mike Garnham wrote:
> 
> I wonder if I should write "Mike's Definitive Guide to Shed Building" and post it somewhere obvious before I get accused of being too repetitive?
> 
> ...



I think that is a great idea. A guide to the different type of shed and workshop buildings, design, construction, materials, damp proofing, insulation etc.

A nice project for the christmas holidays, Mike.  

Tony.


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## johnf (10 Dec 2008)

Paving slabs laid on sharp sand is adequate for a lightweight timber shed quicker and cheaper to.

the 150mm concrete slab on a hardcore base is complete overkill


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## Smudger (11 Dec 2008)

johnf":3ukngttn said:


> Paving slabs laid on sharp sand is adequate for a lightweight timber shed quicker and cheaper to.
> 
> the 150mm concrete slab on a hardcore base is complete overkill



My experience was that the slabs moved over time and made the floor uneven. I now have a slab, and it is great. Mind you, I bullied two of my sons into laying it for me...


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## Rich (11 Dec 2008)

johnf":2y9ciq64 said:


> Paving slabs laid on sharp sand is adequate for a lightweight timber shed quicker and cheaper to.
> 
> the 150mm concrete slab on a hardcore base is complete overkill



Depends what machinery you have

Rich


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## MikeG. (11 Dec 2008)

Escudo":2ex3h61g said:


> > Mike Garnham wrote:
> >
> > I wonder if I should write "Mike's Definitive Guide to Shed Building" and post it somewhere obvious before I get accused of being too repetitive?
> >
> ...



Sorry Tony.........it isn't going to happen....!!


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## MikeG. (11 Dec 2008)

johnf":2l4s3uok said:


> Paving slabs laid on sharp sand is adequate for a lightweight timber shed quicker and cheaper to.
> 
> the 150mm concrete slab on a hardcore base is complete overkill



The 150mm depends on the area of the shed, but the principal is certainly not overkill if you are looking for a decent long-lasting building. If you are just sticking something up to store the garden tools and some bikes, then it would be unnecessary. If you are building a workshop...........do it once, and do it properly.

Mike


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## Benchwayze (12 Dec 2008)

Feather edged cladding (Clapboard) is not so 'pretty' as T/G or Shiplap, but it's designed for the job, usually of treated timber and it won't open up due to prolonged exposure to sunlight. (Due south aspects esp.).
Also, whenever a strip needs replacing it isn't so big a problem as with 'mating' boards. 
HTH


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## gedereco (13 Dec 2008)

We have always done bases of 150 mm thick as that is the minimum i recommend to all our clients , in the end of the day you want to put it down once and forget about it for life as it takes about 25 years to get concrete to full strength. it should out last your shed. a bit of outlay and work at the begining is worth it or if you don't want the hassle get a firm like mine to come and do it for you, for a reasonable price that is.


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## CWatters (15 Dec 2008)

Would be interesting to know typical costs for a professionally laid base.

I decided to do my own. The slab was 5m x 4m x 150mm and I wanted it almost flush with the ground so I could drive a mower in. Site had a 6" slope from one side to the other. It took...

Digger hire (weekend)
Dumper hire (3 days)
Wacker plate hire (1 day)
7T Skip hire 
3 bulk bags MOT
1 bulk bag sand
2 bulk bags gravel (drainage around edge)
Stainless steel studding
Membrane
6 x 2 formwork
3 cubic meters ready mix
Two brick courses and DPC

Total cost was >£1,000 but I daren't add it up.

The dumper was used to transport dirt to the skip and concrete back the other way due to site layout. I'd definitly go for ready mixed concrete again. I was concerned about having the hired kit waiting around for days but the concrete co said they could deliver at 24 hours notice and they did. The delivery driver even helped get it placed. I think it would have been impossible mixing that lot on my own even with a mixer. It was hard work just tamping it down and levelling off. The studding was used to make long bolts embedded head first in the wet concrete and will be used to fix shed down later (windy location).


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## filsgreen (15 Dec 2008)

Have you posted pics of the finished product Colin?


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## CWatters (15 Dec 2008)

Not yet. Got lots of other stuff to do so may not get the actual shed built until warmer weather.

Some drawings and a photo here ..
https://www.ukworkshop.co.uk/forums/view ... hp?t=24724

Discovered I probably should have extended the hardcore over a larger area than the area of the slab.


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## gedereco (17 Dec 2008)

Hi colin a rough cost would be about £1200 in and out finished in a day the only thing different we would of done would raise slab out of ground and put a ramp upto the doors on shed so any ground water always hits slab and not mortar joints


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## MikeG. (17 Dec 2008)

gedereco":7gdtbczn said:


> the only thing different we would of done would raise slab out of ground and put a ramp upto the doors on shed so any ground water always hits slab and not mortar joints



I presuming that this shed is going to be built on a low brick plinth.....overcoming the point raised by gedereco. Two courses are all that are needed to turn this into a first-rate job.

Mike


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