Advice on rotting shed

[Jonm]

,

Yes, It rotted because its on the concrete, sitting in a slight puddle. The pent roof dumps all the rain behind the shed and the concrete has a slight dip in that same area. Plus I didn't clear out the weeds behind it last year, so they did their work and found some rotted corners behind belongings stored along the back wall of the shed. wasn't till I moved these items for the first time in 2 years that I realised what had happened. It doesn't have a damp proof layer (unless you mean the paint?) and it was made of untreated wood.
@Bm101 has/had lots of things I don't have: 3 friends willing to help, surplus paving slabs, space to move the shed to (mine is 40 cm from the house behind), presumably he also had a few non-december days/weeks to dry it out and didn't need to use the shed during that time. Plus he wanted to keep his shed, whereas I only need mine to last till the summer - when I can build a new one.
If I tried to raise it up now I'd have to move everything in there, detach the floor completely and leave the shed suspended in the soon-to-be-frost.. presumably I'd then have to lay a few courses of brick in the cold/frost before replacing the shed. And I'd still have the shed next door to it thats developing similar issues and the fact that both together are too small/cold for what I want to do with my shed-space. On top of that (on the plus side) I'd have to buy a load of festool tools so that I could do everything in the front room for the next few months!

You have clearly worked out what is causing the problem. I would only add that for your new shed, gutters with downspouts are a good idea. Outfall preferably to a drain or to a soakaway or anywhere away from the base.

With regard to your existing shed it may be a good idea to add gutters, too late to stop the rot but it may make the inside drier.

 

[artie]

I've seen people putting down sheds on top of damp proof. They seem to forget that it works both ways. You can end up with your shed sitting in water on top of the damp proof course.

 

[Tom K]

A badly built shed is for life not just for Christmas. Build to Fail, Fail to Build. What is this I don't.....

 

[OldWood]

My original workshop was here when we moved in in 1975. The base at the front rotted out about 15 year ago due essentially to the same problem though the wood was reasonably sturdy, and like the OP everything above 500mm was fine. I supported the roof off the concrete base, ripped out all the rotten framing, placed a single course of concrete blocks off the concrete pad all round, dpc, screwed down timber pad and then connected back to the original frame. I'm led to believe that concrete blocks don't pass rising damp but have never checked that out.

Do that and clear out the existing floor to the concrete pad and lay interlocking foam 'rubber' flooring pads.

Rob

 

[Richard_C]

I have a similar problem in one corner of an inexpensive summerhouse/shed that I bought 15+ years ago. You can see that one corner has dropped because the roof has a slight 'kink' and you can poke your finger through the bearers in that corner. My plan, when my son is home next week and can wield the long crowbar or the lump/sledge hammers (I can't do both at the same time) is to clear a little under each panel upright - they are sound - lift the sagging corner from outside the shed with crowbar and hammer half bricks, bits of hardcore, whatever, under each upright. Then do bit of cosmetic + bodge with the floor/base frame where they are holy. Hoping for another 5 years. Consulting actuarial tables, if I can get 5 more years out of this one the next one is more likely to last me out....

 

[Shane1978]

If you’re wanting cheap wood for sheds and such like just keep a look out on Facebook Marketplace - round our way people are always selling off cuts of ply, left over 3x2 etc etc. Cheap as chips.
And don’t go to B&Q. Overpriced and poor quality. Go to a timber yard.

I hope it works like that in my area too. I’m going to work hard on the design/materials list over winter and then go into womble-mode. Collecting anything that fits the description of the items on my list. Will make Facebook Marketplace a regular haunt, thanks.

 

[Shane1978]

,

You have clearly worked out what is causing the problem. I would only add that for your new shed, gutters with downspouts are a good idea. Outfall preferably to a drain or to a soakaway or anywhere away from the base.

With regard to your existing shed it may be a good idea to add gutters, too late to stop the rot but it may make the inside drier.

That’s both a good idea and one that’s possible for me because I’ve already got a long piece of guttering in the garden. Was tempted (by the wife) to take it to the tip recently, but I think I can get it to take water away from the back of the shed. Today was slower than expected, but I can see this is all going to have a big effect on its life expectancy.