The Brew Cabin

Posted: **Sun Jun 03, 2007 6:41 pm**

I want to put a 5'x7' shed in my garden. The garden which is currently lawned is quite soft under-foot and a bamboo stick can be hammered in to a depth of 2' easily. I think there is a lot of top-soil.

I have looked throughout this great site and have found advice to dig 150mm, lay 50mm MOT, then a DPM, then 100mm concrete.

However I'm not very strong (I have already ruled out big slabs as they are too heavy for me).

Rugby say that their Path Mix is suitable for paths and shed bases. Apparently you pour it on dry, level it and water it in.
It gives directions for 50mm depth - which already contradicts advice on this site.

Can someone tell me if this product would be OK for me please?

Posted: **Sun Jun 03, 2007 8:37 pm**

i have never heard of that before but it looks a right pile of s**t
a base 50 mm thick will not be worth a carrot.
100mm concrete is the bare minimun,sub base is what any pro would do ,but this path mix looks like one of groundfarce's creations
cheers LLL

Posted: **Sun Jun 03, 2007 8:39 pm**

I can't comment about the concrete stuff, but was wondering whether the shed you're planning already has a floor or if you plan to use the pad as the floor.

If it's the former then I'd be thinking about building some masonry plinths to stand the shed upon rather than pouring a pad.

Others may have different, mre qualified thoughts... ???

Posted: **Sun Jun 03, 2007 9:12 pm**

50mm thick base

Id have more confidence in using digestive biscuits to be honest. Id go for a 'crete pour seeing as you have ruled out slabs.

Posted: **Mon Jun 04, 2007 12:30 am**

Hi, thanks for all the replies.

The shed I'm looking at does have a base (stirling board).

What is entailed in creating masonry plinths?

Are they supposed to be one on each corner? The shed is 5'x7'.

Posted: **Mon Jun 04, 2007 12:31 pm**

I've had a word with a carpenter/gardener friend who has done a few sheds in his time. Apparently there are a number of ways that one can go:

(1) Pour a pad
(2) Use paving slabs
(3) Hammer some 3' lengths of treated fence post in to the ground, level them up and then sling some treated timber 'bearers' across them
(4) Just place the treated timber bearers directly on the ground at right angles to whichever way your shed floor is supported.
(5) dig some smallish holes (about 30cm square and 10-15cm deep) fill with concrete, level off and then raise the shed off the ground using supports placed on these pads (bricks, timber, etc)
(6) dig some 10cm diameter holes about 50-75cm deep (using a borer or fence post digger) drop in 60-85cm (depending on the depth of the hole and the level of the garden) lengths of 10 cm plastic pipe and fill them with concrete and use them to support the shed.

Apparently, the most he ever leaves is 45cm between bearer/support centres and always tries to put a layer of damp proof membrane between the bearers and the shed.

I'm not cetain how many of these different methods he's tried but he says that the method he uses the most is number (4) for smaller sheds.

Another point to note is that it might be best to tie the shed down in some fashion (either to a wall, a deepish fence post or directly to any supports you have sunk into the ground) to stop it shifting in any high winds.

This is all hearsay, however, and I can't guarantee that any of these methods would be suitable for you, others here may have more useful first-hand experience.

Posted: **Mon Jun 04, 2007 9:30 pm**

i suppose the cheapest is to lay 75mm square fence posts perpendicular to the floor joists,just a bit of a bugger leveling mud and hoping it wont sink
LLL

Posted: **Tue Jun 05, 2007 2:31 am**

Wow, IanMelb, what an amazing answer. Thanks for putting so much time into it for me.

I like the sound of number 4 - "Just place the treated timber bearers directly on the ground at right angles to whichever way your shed floor is supported".
lutonlagerlout appears to agree although he's scared me with "..and hoping it wont sink"!

Would the layer of damp proof membrane between the bearers and the shed be better on a little sand under the bearers so that they stay dry too?

If I bought small slabs instead and laid them out on just sand without using the MOT layer etc, would they have less chance of sinking than bearers? I certainly couldn't use a wacker plate.

Posted: **Tue Jun 05, 2007 10:07 am**

Would the layer of damp proof membrane between the bearers and the shed be better on a little sand under the bearers so that they stay dry too?

Off the top of my head, I'd say it wouldn't make a great deal of difference unless you actually wrapped the bearers in the DPM - and then there's a risk of the timber not being able to 'breathe' properly. If it's properly treaed it should last for 10-20 years, but can also be easily replaced. The bearers serve at least two purposes, (1) raise the shed off the ground so that ground water doesn't flood in (2) allow air to circulate under the shed floor which helps keep it intact.

If I bought small slabs instead and laid them out on just sand without using the MOT layer etc, would they have less chance of sinking than bearers? I certainly couldn't use a wacker plate

If you're confident that the shed will be enough off the ground to avoid water ingress then it should be ok. There may be less 'sinkage' due to the area being greater (images of elephants dancing on a wooden floor with stilletoed lady partners spring to mind - it was an old physics class - despite the fact that the ladies weigh far less than the elephants, they do more damage to the floor because their heels concentrate a lot more force than the elphants' feet).

Anyway, if it were me, I'd probably lay some slabs down under the bearers (where the total area of the slabs would be greater than the area of the bearers) and then put a run of DPM over the top of the bearers. Belt and braces.

I'll check with the gardener and if he says different I'll post it.

Remember to keep in mind how the shed is going to be 'wind-proofed' (if necessary)

Posted: **Tue Jun 05, 2007 9:50 pm**

Slabs and bearers. I was hoping for one or the other.

I'd like to put the shed against a fence, but due to having more topsoil than the neighbours; my garden is cut into a slope going down to the fence. The slope only occurs for about 10" outwards but is steep so that the fence doesn't rot.

Do you think I should mix up some concrete to make a solid block of say 1'x1' across the fence base for the longest part of the shed 7'?

Maybe I could still use timer bearers and DPC (1000 or 1200?) for the rest?
The fence in question (neigbours) is not stable and its posts are rocking - so maybe if I can use this new concrete back bit to hold the shed in the wind (the fence certainly wouldn't hold much).

If you think the idea is good can you please advise on what mixture of sharp sand, cement and pebbles should I use for that and how many bags do you think I will need?

Posted: **Tue Jun 05, 2007 10:43 pm**

Rather than maybe overcomplicating the situation, if I wanted to use just one method then I'd go for the bearers (as long as they are treated then any type of DPM should be OK, it might not even be necessary, but can't do any harm for little outlay)

Then, after a while, I'd check for any sinkage - if it was quite obvious then I'd consider popping some cheap flags under the bearers (although I'd have to call in a couple of mates to lever the (empty) shed up whilst I did that).

Unfortunately, I'm in no way qualified or experienced eneought to advise anyone on any concrete stuff

Posted: **Wed Jun 06, 2007 6:56 pm**

My Bro in Law just put up a cheap B&Q shed and he used 3 concrete fence posts to stand it on with some broken slabs to level them. Mind his garden is like mine - solid clay.

Posted: **Wed Jun 06, 2007 7:06 pm**

I've put sheds on bearers without problem before although I prefer to lay the bearers on a bed of compacted hardcore.

The proper way is to do compacted hardcore and then a 4" slab though. I would do it this way and I would look around for any scrap metal you may have and chuck that in as reinforcement; I put my old bike into the drive of my last house!

Posted: **Wed Jun 06, 2007 7:12 pm**

there was summat in the paper the other week about a tree in scotland that has grown around an old push bike
legend goes a young soldier met his sweetheart there before he went away to war
he leant his bike on the tree and they walked together
then he went to france...............

he never came back and over the 90 years the tree totally enveloped the bike
no local dared touch it in case he came back for his sweetheart
and now all that is left is the handlebars sticking out of the trunk
who knows if its bollox but a nice tale anyways
LLL

Posted: **Wed Jun 06, 2007 7:16 pm**

found it!
bike tree
cheers LLL

The Brew Cabin

Rugby concrete path mix as a shed base? - Shed base using dry concrete mix