Sheds

As I've mentioned before, the quality of the wood used in pretty much everything "wooden" made, is a bit like "forced rhubarb." It's timber from "sustainable forests." So lacks density and is likely to rot, unlike pitch pine which was used for Victorian window frames, many of which in houses of that era are still in good condition.
I think there is also variable quality in anything described as "Tanilised" or "pressure treated." I'm sure some don't get much more than a "coat of looking at."
Same with Waneylap fences. The 4ft fence panels between ours and the neighbouring semi's side drive are now the best part of fifty years old, have had no subsequent treatment, but are still just about "hanging on." Several of those in the fence I erected in our back garden had to be changed after fifteen years.

With any shed, I believe you have to get it up off the ground by about six inches, as is our tea-house I built of reclaimed softwood and roofing ply panels. I think it better to have some sort of protection that covers the surface, like my mahogany exterior Woodsheen, or a similar polymer paint, rather than stuff that's supposed to sink in.

To disguise the fact that this building is off the ground, supported on brick piers on pavingstones, it has "skirts" made from Victorian style skirting boards that are two inches clear of the surrounding path. The "fall" of the path is away from the building and the overhang of the roof keeps some rain off the sides. There's enough clearance for me to get a long pressure spray lance under the skirts to give the underside a spray of clear Cuprinol every five years or so.

You can just about see the gap in this photo. As there's no skirt at the back it gets plenty of air circulation underneath.



Thirty-two years on this year, there's no rot. I've forgotten how many coats of Woodsheen it's had over the years, but it was certainly worth it. It got three coats after I finished it.

Here after one coat thirty-two years ago. Over the years with subsequent applications it's become a really deep brown.




I never painted the underside of the roof, just a coat of Cuprinol and nothing since, as it's out of the weather it still looks like this. It looks a bit flimsy but the whole roof will take my 12st when I'm up there painting the top.

 

I'm looking at this now and it appears the shed sides go down onto the DPC material?
The DPC is achieving nothing, if that is the case?, other than directing the water from the roof, (no gutter), and the sides straight inside.

The sides of the shed should overhang the base allowing the water to drain away.

In short the base should not be bigger than the shed sides.

 

I'm not familiar with metal sheds so my comments are based on wooden ones, the sides of the shed boarding traditionally would always overhang the floor.
The floor would be suspended on timbers, (sleepers) , so the whole thing is off the ground.
I'd not spend any more money on it.

It's probably too much for you at the moment, I know, but the whole thing needs taking away, a new floor making, built up off the paving and making sure the sides of the shed actually "shed" the water.
At the moment it doesn't matter what you do it will always leach under the sides, the DPC is actually not helping, its just making the problem worse IMO.

 

Seems there are a good few ytubes on those Yardmaster sheds and even the newly built ones report leaks !

This one shows how he fixed the leaks around the base with does seem reasonably easy to do, one side at a time by using some wedges to hold it up enough to get the membrane under.

As it goes over and down the edge of the base it would seem to negate need for a roof gutter.

Better not mention how you have half covered the house drain cover !

 

I was thinking along the lines of Marley and having two sheds side by side. These two would give you an over all space of 14 x 10.

7x5 Forest Apex roof Overlap Wooden Shed | DIY at B&Q

 

That is interesting, apart from the gap I noticed where there is a bracket holds in the shed to the floor, a gap in the membrane, apart from obvious joins that are bound to be required, as you cant go round the whole base in one.
It is only a stop gap, and probably the big problem with metal sheds, they are only really a place to put the mower and a few gardening implements, not really for storage of other stuff.