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Collection, Preservation and Display of Old Lawn Mowers

How tough is your shed?

Bit random this, but late of an evening when one has a glass of the water of life by one's side, philosophy creeps in.

My shed is dying. To be honest, it was probably past repair when I moved (it came with the house) given that I pulled the front off it the first time I got the mower out, and the intervening 4 1/2 years haven't helped. That and fixing the house up took priority... I need a new one, but the floor will need to be able to support my 18" Atco Standard. 12mm tongue and groove seems to be the standard flooring as far as I can see - will that do the job, or do I need extra support underneath? Especially as there's a fair chance that my Allen Scythe will join it, when it can be excavated from mum's hayshed.


What say you, oh men with sheds?

wristpin Thu, 09/04/2020

What’s the shed sitting on and if an existing timber floor what size and pattern are the joists?

Why  not a solid concrete floor?

Lee Smallwood Thu, 09/04/2020

As wristpin said, can't beat concrete as a strong base, easy to level with a level shuttering around the perimeter, and you can insulate it with celotex or similar before concrete is poured but the excavation needs to be at least 100 mm less than floor level depending on the thickness of insulation and concrete but if raising roof height isn't an issue then this can be installed higher. Check outbuilding regulations for heights, but as a rule as long as building is no further than 1 MTR from existing boundary a flat roof can be up to 2.5 MTRS high. 

a wooden shed floor is required the base for it will need to be level and we'll compacted. Will need to see what is underneath original floor to get an idea of which base is most cost efective.

As a carpenter, I would consider a wooden deck frame,  made from 3"X2" supported by 4" posts, if solid slabs are underneath the posts will be able to sit on top rather than dug in and concreted, usually floor joists are 400mm centres but if more support is needed then this can be reduced. American style deck frame with supporting timber under joists is useful and reduces the posts that need to be dug in. 

Celotex or similar can be used if insulation is required and 18mm exterior ply can be put over the top and screwed down, the shed base if buying a shed can be go directly on the frame if joists have been installed opposite to the floor.joists for the shed.

any timber can be used, a decent timber merchant, jewsons, Travis will keep 18mm t&g if you like the look. Raising the floor with joists will ultimately raise roof height but aid with air flow and deter damp issues, I would use a high quality weed control membrane if timber was used, or a heavy duty DPM if using concrete.

Off the shelf shed will probably use 12-15mm t&g flooring on 50mm joists. Not ideal if base isnt level, so supporting timbers will need to go down, opposite to the floor joists at 300-400mm centres and packed level, shed suppliers will usually keep rough sawn 3x2 to do this they can be layed flat and the shed floor can be screwed down to them.

Hope this helps. Lee.





Adrian Thu, 09/04/2020

Ah yes, I'd forgotten in my late evening light inebriation that people tend to take things quite seriously round here. I shall return the favour and do likewise.

This is the planned location of the replacement shed Unlike the guy we bought from, I don't have about six cars, so don't need to park on the concrete, and if I go for a 6x10ft (current one 6x8) shed it won't block that much light as it will fit between two windows. Plus it'll use an ugly space that's not a lot of use otherwise.I'm not worried about having a corridor down the side of the house, as we have that already with the current arrangement.

So there is a solid base, but with a slight slope on it to the grass side. I was assuming that I'd have to put slabs down to raise the wood off the ground, so I'll have a step (ramp) whatever.

OK, I could say a lot more, but I think I'll let you have a say first, as you seem to have more clue than me.

PS Yes, I know the fence is shagged, but it'll be a lot easier to put a shed up without it, so I've left it to die.

wristpin Thu, 09/04/2020

If you use the existing ( decent?) concrete base you could stand the shed on a run of old non absorbent ceramic tiles , may be two thicknesses on the down hill side making sure that it overhangs all around to form a drip. Then inside  put a 1” strong screed all over so that it is higher than the outside. A cement slurry will help it bond to the concrete . I did just that for a 12’ x 25’ shed at a previous house on a pretty rough concrete base about 25 years ago and I happen to know that it’s still as good as the day it was laid.

May be better to get a pro to do the screed to get the level an flatness spot on.

Make sure that you get the house side gutter installed while you can get at it so the that fall of the roof is not dumpling it’s water between house and shed.

Adrian Thu, 09/04/2020

Mm, a screed might well be a better bet than slabs, as I suspect I'd have to stand those on a bit of cement to level them up anyway. The existing concrete is, as far as I can tell, solid as Gibraltar.

Lee Smallwood Fri, 10/04/2020

A screed would need to be quite thick as it might crack in the shallow area, depends how thick it will need to be at the deepest end, although quite expensive a self levelling compound (latex) might be the way forward if it's only a thin layer to make it level. Anything over 25mm I would agree with Angus on the screed. But would suggest a stone dust concrete rather than ballast. Would be a nicer finish too.

Keith Wootton Fri, 10/04/2020


Looking at your posts, I think your plan is to put a wooden shed on the concrete drive and that you are asking about the strength of the floor in standard versions.

When I have put up this type of shed in the past, I have placed extra battens under the floor to provide additional support. That might be enough but an additional precaution would be a sheet of OSB (cheaper than plywood), cut to fit the interior floorspace and laid on top of the floor that comes with the shed. That should be enough to spread the load for any potential mowers - in one of my sheds (8x6ft) this arrangement is happily supporting a 24" Dennis Z Type and most of my grass boxes and detachable hand mower handles. If I remember correctly this was 12 or 15mm OSB, so not expensive in the overall project context.

Some suppliers will be able to cut on site to your dimensions if the normal 8x4 is too big for your car. I've also put a sheet of rigid moisture-resistant sheet under the OSB to provide some basic damp-proofing - it seems to be working.

Whatever you choose to do, I would also recommend an additional treatment with wood preserver for the base/floor before you build the shed.

Hope that helps.


Covbandit Fri, 10/04/2020

I need to do mine soonish (been saying that for 3 years). I have the wifes wisteria pushing it over and holding it up and electrics for my pond powered from it.

I agree with putting battens down to level and stop the shed just sitting in all that water for 20 years.

I have a rat problem at the moment and guess where they live? Yep under my shed, so I suggest you use some sort of wire meshing nailed or screwed around the bottom to stop the buggers getting under.

The finer you go will hopefully sort any mice problems also. 

I'd suggest this or very similar...500mm x 3mtr

500mm bit could be cut into 5 x100mm x 3mtr should very nearly go right round a descent size shed and no rusting

wristpin Fri, 10/04/2020

My screed was one inch minimum and was sharp sand and cement and was by someone who knew what they were doing - not me! I did watch for a bit and the trick seemed to be to strike the balance between it not being runny but still workable. He didn’t hang about as the whole shed was done in one continuous lay. He may have used an additive of some sort. 

In the five years that I remained there it showed no sign of distress with a 30” Dennis rolling in and out,  and it’s  still good now . The beauty of an internal screed that raise the level above the surrounding concrete base is that no water seeps underneath .

Unless treated with the appropriate floor paint any wood, OSB, or flooring grade chipboard absorbs spills and may deteriorate quite quickly. Also it one is welding ,plasma cutting or grinding ,concrete doesn’t catch fire!

Horses for courses - and pockets!

Adrian Fri, 10/04/2020

Got it in one, Keith. Extra battens and/or a top layer seem sensible - though the standard size of OSB is carefully calculated to mean lots of fiddling about  whatever size shed I get! That would also help with any rail across the doorway.

I am under no illusions as to my concreting skills - I don't have any. I suspect I could do it with someone on hand to show me... but then why not just get them to do it? Many years ago I helped Dad (no longer about to help) lay a greenhouse foundation - I just mixed the stuff on a day with driving drizzle, by the time we finished my coat had picked up so much cement it  genuinely stood up on its own! Getting it laid for me (oo er) would probably also give me a useful contact for further work that needs doing.

My pocket is not hugely deep - I'll have to investigate costs (once people can do this sort of stuff again!) - so it will probably end up as a compromise.

Incidentally, SWMBO is worried that we'll interrupt the flow of water off the concrete and end up with a soggy passage - any thoughts?


wristpin Fri, 10/04/2020

Soggy passage or soggy bottom - one of life’s dilemmas.

Where is this “ flow of water” coming from. The shed will capture its share of rainfall which can be directed onto that nice bit of green Next door - via a water but of course - and the rest will do whatever it does now.  Perhaps it’s the shed that’s the problem, not the rain. Men need a shed!

hdtrust Sat, 11/04/2020

Sheds no half measures here! We moved into a new storage area last year,concrete floors,plinths,brick walls and a new sheeted roof with lights.The problem was shelving! We always use scaffolding as it will take 1 ton every 6 square feet.After getting 4000 lin ft plus all the clips, off we went Meccano for grown up lawn mower collectors!

Just be warned the bloody Chinese have struck again! making cheap scaffolding,we are now in the process of altering the structure to stop the poles from bending!

Fortunately I have a further 2000 lin ft of old non galvanised scaffolding made in Sheffield that will do the job.

The use of seltex be warned,yes ideal for insulation,no good for when using mobile phones within,as you will not get a signal! My Winery was built that way floors under the concrete, in the walls, and the roof linnings.Makes bloody good wine having 280 gallons of Elderflower wine on the go at 16% proof,Also various concoctions of spirits, after tasting that lot who needs a mobile phone!

Happy Easter to you all

From The Hall & Duck Trust hic!!!! hic****! 

Adrian Sun, 12/04/2020

No wonder Celotex blocks mobile signal - it's got an aluminium foil layer, so you've built a Faraday Cage!