Shed base and floor questions,- SORRY.

[garywayne]

Hi all.

I have been watching the shed builds in the hope that I wouldn't have to ask these questions.

I need a shed, but I am going to move house as soon as it is refurbished and decorated.

The shed is going to be 10 feet by 12 feet, with no heavy machinery.

1)- Would patio slabs with concrete blocks on top be enough to build the shed on?

2)- If the above is good enough, do I then put on a DPM, then the joist, then a poly membrane, then the floor boards? Or. Do I do the above but put more joist in between the first joists and the poly?

3)- What is the minimum and maximum space between centres of the joists?

4)- What distances should the joists be supported?

5)- What would be the best for the floor joists? Pressure treated, or tantalised wood?

In writing this I have just noticed. Do I put up the walls before laying the floor?

As my wife and I intend to move, and I desperately need to vacate the dinning room, I have to build this shed as cheaply as pos. In saying that, It doe's have to be workable in during the winter months. So any suggestions will be more than grateful.

 

[OllyK]

The shed is going to be 10 feet by 12 feet, with no heavy machinery.

1)- Would patio slabs with concrete blocks on top be enough to build the shed on?
Depends how you lay your slabs. I've done this in the past, digging down to firm ground (a spade depth or so depending on your garden), fill with quarry bottoms, compact and then lay the slabs. Never moved in 6 years

2)- If the above is good enough, do I then put on a DPM, then the joist, then a poly membrane, then the floor boards? Or. Do I do the above but put more joist in between the first joists and the poly?
I didn't bother with anything, but concrete blocks can absorb water so I'd put some kind of membrane between the wood and concrete. If you are insulating the floor, the vapour barrier should be on the "warm" side of the insulation.

3)- What is the minimum and maximum space between centres of the joists?
depends what you're putting in there and if you are supporting at just the edges or in the middle of joists, also depends on the size of joists. If you use 2x8s, then 15" centres will probably suffice - make sure you put a couple of noggins in per joist!

4)- What distances should the joists be supported?
A 2x8 will cope with 10 foot happily enough (and more), but for larger spans I consider additional supports or beefier joists i.e. 2x10 (it's the depth that's more important than the width)

5)- What would be the best for the floor joists? Pressure treated, or tantalised wood?
For the most part they shouldn't be getting wet as there is a shed over them

In writing this I have just noticed. Do I put up the walls before laying the floor?
Personally I'd get the walls attached to the joists / floor structure directly rather than going through your surface flooring, however, you could floor and stop short to make life easier with construction

 

[Anonymous]

Hi Gary,

the recent shed building threads have been very good but they are very complex. You don't necessarily need such an expensive and complex building. There are lots of people on the forum who are working from garden sheds (or the like).

My shed was built using 2x2 timber bought from wickes. It sits directly on patio stones. It has no damp proof membrane. I've left space between the patio stones which allows air to circulate freely underneath. I've coated all the timbers in several coats of preservative.

Building your own shed is more expensive than buying one off the shelf. The main thing about building your own is you get exactly what you want. I can bump into my shed without a wall moving. It was built with an extension in mind. The roof is my only window (for security and light).

If you can afford the best then go for it. If not then ignore lots of the building methods used in the current threads. The main thing is that you get it finished and start using/enjoying it.

Dave

BTW. floor first, then walls.

 

[Johnboy]

Agree with most of what olly says but think that with no heavy machinery 6 x 2 would be plenty and standard centres is 16" not 15". Allows insulation to be fitted without cutting it. I would use pressure treated (same as tannalised) only for the floor. For the walls I would use 4x2 on 24" centres. Clad the outside with pressue treated feather edge and the inside with 12mm OSB. 18mm Water resistant chipboard flooring for the floor and 12mm OSB for the roof sheeting.

I built my shed like this (mine is smaller so I used 4x2 for the floor and roof) about 10 years ago and it is still dry and rot free just supported on paving slabs bedded on sand.

John

 

[garywayne]

Hi, I would like to thank you all for replying. You have certainly put my mind to rest. Because of my financial situation I have a fear of doing things wrong and not being able to finnish because I can't afford it.

Now I can draw up a plan, and start pricing it all up.

Thank you again.

 

[CHJ]

Gary, as you are only after a short term solution I would certainly investigate the ready made units mentioned elsewhere, adding insulation and internal cladding yourself would enhance it's quality considerably and be a much smaller task for you and Sheela to tackle.

Also remember that under current regulations you are going to have to get any fixed electrics certified one way or another which will be another imposed cost you might not have thought about.

Just getting a base ready yourself and having a company erect it for you may also be worth the extra.

If you do go for a pre-manufactured unit and the floor seems lightweight for the lathe etcetera then you can always lay a stiffening sheet of ply or flooring panel in the localised area.

 

[ByronBlack]

As it's temporary, I would really suggest a ready-made one. You can get a base sorted in a day or two, and put a ready-made one up in another couple of days.

Also, the added benefit is they are easier to knock-down and take with you when you move.

 

[engineer one]

gary, think about your own labouring abilities. :?
i still personally feel there is much to be said for using
wooden railway sleepers, up here they are about
15-20 quid each they have many advantages.

a shed raising would be useful though. :lol:

paul :wink:

 

[wizer]

even 6x2's seems overkill, mine is all 2x4's and it's 18x8ft

 

[garywayne]

Hi I'm back.

If I can find a shed the right size and price, then I will go down that rout. The problem is that there are no sheds the right size in my area.

I have my eye on one on e-Bay which is up near Swindon.

Paul, as for sleepers, :shock: I would think that a few concrete blocks would be cheaper, and certainly easier for me to handle.

 

[engineer one]

gary you may be right, but wood always easier to drill into :lol: :lol:

paul :wink:

 

[garywayne]

I don't know Paul. I've been told that these SDS drills are pretty darn good these days.

 

[engineer one]

gary, thinking more seriously about the fact that you want a temporary structure( that is temporary for you), and of course that you just want to
buy an sds drill :twisted:

around this time of year there are many companies up here doing specials on sheds, cause they want to get rid of stock.

not sure what part of soton you are, but when i come off the m3, and go down toward west end, there is i think a big shed company, or garden centre that sells sheds on the right hand side
after the phsyco hospital/sorry not pc, but you know what i mean.

maybe the logic is to go there, and see what they have to offer, and
what they would suggest in terms of piers, come what ever.
may well be that they would just be happy to build it
on top of pavers. or they could suggest another more cost
effective solution.

since you are working mainly with hand tools it might be
the best solution.
:twisted:
paul :wink:

 

[ByronBlack]

Screwfix and B&Q both do a range of sheds with delivery to pretty much anywhere in the mainland UK so i'm sure one of them do a shed your size.

Walton's do a nice range (although they were the ones that delayed the delivery of mine hence the need for me to then build one) so it's worth a looK!