First post - shed help needed please.

[brokentechie]

Hello all,

Finally at the grand age of 42 I've managed to get on the housing market for the first time in May.

We have a big rear garden that already has a decent shed in it, although the roof is somewhat dipped due to lack of proper support however after replacing some damaged panels where it looked like a lock had been smashed off it seems relatively water tight and a falling apart bike shed that currently just has low value odds and ends in it due to the lack of security.

I have a dream - a nice shed cum workshop where i can have a partition at one end for our bikes, dry and condensation free "workshop" area for my tools and boys toys and a lean to log shelter at the other end.

When I say workshop the heaviest bit of machinery will be my mitre saw and stand, a bench with a vice which will have a metal top box tool cabinet on it and some racking for various other power tools.

It won't be a workshop per se - I am a weapons engineer now (I apprenticed in the RAF as an aeronautical eng tech) so I won't be using it other than somewhere dry to work on the DIY jobs that need doing to the house (skirting, architrave etc)

The problem: I have read so many builds with absolute abject misery and jealousy realising that I will never have the budget for most of the buildings I have been seeing, so I know a dirty great concrete slab is the best way forward however with the mortgage payments, childcare costs and the amount of cash the full renovations of the house will cost I just don't have the budget to go this route.

I'm after ideas for how best to build my shed on a tight budget so I have a long lasting addition to the house - I have been thinking along the lines of piles to the natural ground level with the immediate area say 1' away from the shed footprint hollowed (as a trench) out to a depth of 200mm and filled with 50mm of pea gravel or similar to act as a soakaway for the rain run off of the shed walls and the inside perimeter of the piles dug out to 150mm. I would guess the piles would need to be 400mm deep at least, and I would use large bore poly pipe as a former

This way I can keep the wood the Mike G magic 150mm from ground level and maximise the roof height (2.5m pent roof planned) as I'll be building within 2m of the boundary wall with my neighbour.

Is this madness? Is it feasible? Am I a loon that should stick to bombs and aeroplanes and leave the woodwork to the real professionals?

If my ideas are dog egg, then what would be the best (budget) route I could take? I'm not trying to do this on a ha'penny however could I justify the cost of a couple of m3 of concrete and the associated MOT type 1 ballast and sand cost etc.

I would aim to run DPC on top of the piles and weed sheet over the inner perimeter - obviously it would be a suspended floor and I would aim for an overall internal floor space of c. 16' x 8' for the shop/bike store (4' deep x 8' for the bike part, with double doors on the end) leaving me with a 12 x 8 shed.

Oh one other aspect is I'm 6'4" and I'm losing a couple of million brain cells every time I enter or leave the current shed and I have a permanent 2" wound across the top of by scalp, hence the recess idea to maximise eaves height - I understand it's the height taken from the natural floor level to avoid PP right?

Anyway, I have lots more questions but I'll leave it there for now, and thank any of you that are still with me at this point

Thanks

BT

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[9fingers]

Hi BT
Welcome to the forum.
Mike G will probably be along in a minute to comment as "Mr Shed" :lol:

My 2p is that your idea seems plausible. There will be an obvious trade off between the number of piles and the depth of the joists to spread the load. Might need to cost that out against a 150mm slab and all the effort digging for the piles.
You might be able to get cardboard tube formers cheaper than plastic tube and I've no real idea on pile depth but with 200mm or so sitting in loose gravel you might need to go deeper for good lateral support.

I think someone on UKW built on piles - might have been "bluekingfisher" or some such user name.

You might need to think about suppressing weed growth under the shed. An annual "nuking" with glyphosate perhaps to maintain air flow under and get continued dryness in the shed. Maybe a trap door to access the area?

Bob

 

[Malc2098]

Hi there, BT,

Welcome to the forum. The Mods will ask you to go over to the welcome page and introduce yourself and give a couple of replies so that the forum software knows you're not a bot, I think.

There have been times in my life when I had always wished I was taller than 5'9", except when I've been in an out of an old, now demolished, shed. So I've felt your pain!

There is a wealth of knowledge and experience on this site, which has given me the confidence to go ahead and build a proper workshop in my garden.

There will be replies to your plea, so hang in there and wait for them to come, and then work your way through, ask anything you're not sure of and then work your way towards a design that suits your needs.

You will get there. I can assure you.

Good Luck.

 

[AndyP]

Hi BT and welcome to the forum. I have no experiance only watched others with a mixture of awe and envy.
Have you read Mike’s thread on shed building without concrete?

See here
viewtopic.php?f=35&t=3308

 

[brokentechie]

Hi BT
Welcome to the forum.
Mike G will probably be along in a minute to comment as "Mr Shed" [emoji38]

My 2p is that your idea seems plausible. There will be an obvious trade off between the number of piles and the depth of the joists to spread the load. Might need to cost that out against a 150mm slab and all the effort digging for the piles.
You might be able to get cardboard tube formers cheaper than plastic tube and I've no real idea on pile depth but with 200mm or so sitting in loose gravel you might need to go deeper for good lateral support.

I think someone on UKW built on piles - might have been "bluekingfisher" or some such user name.

You might need to think about suppressing weed growth under the shed. An annual "nuking" with glyphosate perhaps to maintain air flow under and get continued dryness in the shed. Maybe a trap door to access the area?

Bob

Hi Bob,

Thanks for the welcome and valuable input - when I'm allowed to post pics I'll draw a sketch of the piling plan which will explain a lot more.

Glad to be here and I look forward to seeing more awesome builds to steal ideas from [emoji4]

BT

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[brokentechie]

Hi there, BT,

Welcome to the forum. The Mods will ask you to go over to the welcome page and introduce yourself and give a couple of replies so that the forum software knows you're not a bot, I think.

There have been times in my life when I had always wished I was taller than 5'9", except when I've been in an out of an old, now demolished, shed. So I've felt your pain!

There is a wealth of knowledge and experience on this site, which has given me the confidence to go ahead and build a proper workshop in my garden.

There will be replies to your plea, so hang in there and wait for them to come, and then work your way through, ask anything you're not sure of and then work your way towards a design that suits your needs.

You will get there. I can assure you.

Good Luck.

Hi Malc,

Thanks for the welcome!

I'll go and post now

BT

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[brokentechie]

Hi BT and welcome to the forum. I have no experiance only watched others with a mixture of awe and envy.
Have you read Mike’s thread on shed building without concrete?

See here
http://www.thewoodhaven2.co.uk/viewtopi ... =35&t=3308

Hi Andy,

I have read it and if I get off the ground, my build will likely follow Mike's plans apart from the lintel - idea for piling is to keep the costs of the foundations way lower than 150mm lintels will set me back - if I aim for 16ft x 8ft I should imagine that will be an enormous cost compared to 9 or 12 350mm deep pilings (This I need to check though!)

I know all too well what you mean about awe and jealousy!

BT

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[Mike G]

Welcome to the forum, BT.

There is no fundamental problem with piles, but it is the connection details, and what happens between the bottom of the walls and the ground, which count. If you could produce a sketch section of that detail, as you envisage it, I'll be able to comment more fully. Also, if you dig a hole a couple of spade-depths deep, what do you hit?

 

[brokentechie]

Welcome to the forum, BT.

There is no fundamental problem with piles, but it is the connection details, and what happens between the bottom of the walls and the ground, which count. If you could produce a sketch section of that detail, as you envisage it, I'll be able to comment more fully. Also, if you dig a hole a couple of spade-depths deep, what do you hit?

Hi Mike,

Thanks for the welcome!

Please excuse the blunt pencil, what I envisage is something like the attached.

I'm thinking that rectangle piles actually may be better, and possibly only a 4 or 6" trench around so there's not such a void to step over into the threshold- that said I will probably pour a concrete step at these areas too.

Don't know what I'll hit going down but I do know that there's no sewer or electric cables - currently the plot I have planned has a mix of paving slabs and some concrete so will take a pic tomorrow

Input much appreciated!

Cheers

BT

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[RogerS]

Hi BT and welcome to the forum.

I think the reasoning behind Mike's question was not so much the likelihood of hitting pipes or cables (a valid thought nevertheless) but the type of soil, rock etc which might put the mockers on your plan if you've got to dig down 30 ft before hitting anything substantial to support the piles !

 

[AndyP]

I think butyl might be a bit OTT for weed suppression. The weed matting available from the diy sheds will do the job and it is free draining.

 

[brokentechie]

I think butyl might be a bit OTT for weed suppression. The weed matting available from the diy sheds will do the job and it is free draining.

Perfect thanks Andy

As you can see I'm on a steep learning curve!

BT

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[brokentechie]

Hi BT and welcome to the forum.

I think the reasoning behind Mike's question was not so much the likelihood of hitting pipes or cables (a valid thought nevertheless) but the type of soil, rock etc which might put the mockers on your plan if you've got to dig down 30 ft before hitting anything substantial to support the piles !

Right got you - in all fairness I don't know however there is a substantial block wall 6 courses high all around the property so I can't imagine the ground is too poor, the chap was a builder (I think he died c. 8 years before the lady who we bought the house from sold up) so it's hard to work out what was his work and what's been bodged since he passed - there is lots of uneven slabs laid in random selections and a lot of the concrete drive is breaking up and thin. Then again there is a really well formed ramp to the front door (concrete) and the existing shed looks self built to a good standard too.

The boundary walls are reasonable so I guess the foundations are good and I suspect not too deep.

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[RogerS]

........
The boundary walls are reasonable so I guess the foundations are good and I suspect not too deep.

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"Looks good to me" he said, in the same tone of voice that Marshall Ney used when surveying the field at Waterloo . :lol:

Seriously, fingers crossed for you that it's all good. Better get that spade out

 

[AndyP]

I think butyl might be a bit OTT for weed suppression. The weed matting available from the diy sheds will do the job and it is free draining.

Perfect thanks Andy

As you can see I'm on a steep learning curve!

BT

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Oh and some chicken wire to stop rodents etc getting underneath.

 

[brokentechie]

I think butyl might be a bit OTT for weed suppression. The weed matting available from the diy sheds will do the job and it is free draining.

Perfect thanks Andy

As you can see I'm on a steep learning curve!

BT

Sent from my SM-G935F using Tapatalk

Oh and some chicken wire to stop rodents etc getting underneath.

Assuming I use a ladder type arrangement for the floor frame then do I need to worry about rodents? It'll be fairly open and easy enough for the local cat population to get underneath - that way they can have a rat snack after they've used our plot as a toilet!

If there's no insulation between the joists and it's completely overboarded with OSB then access to the shed shouldn't be possible?



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[9fingers]

If there is room for cats to get under then possibly no need for the chicken wire. It is the smaller gaps that could give sanctuary for rodents from the cats that need to be protected or avoided by design.

Bob

 

[Mike G]

You seem to be suggesting a reduced ground level under the building. This is just a sump, unless you have an active drainage system, so that in heavy rain or a snow melt you would have water pooling in there to the depth of the surrounding ground. A six inch gap under the building is not a great plan, as said, because rats, badgers and foxes love gaps like that.

There are lots of ways of achieving the principle of having the lowest timber raised 6 inches above the ground level, with building on a slab. Broken up paving slabs as a dry stone wall. Used car tyres filled with crushed hardcore, ballast, or shingle. Gabions. Your imagination is the limit. But avoiding an accessible void and creating a sump are fundamental.

 

[brokentechie]

You seem to be suggesting a reduced ground level under the building. This is just a sump, unless you have an active drainage system, so that in heavy rain or a snow melt you would have water pooling in there to the depth of the surrounding ground. A six inch gap under the building is not a great plan, as said, because rats, badgers and foxes love gaps like that.

There are lots of ways of achieving the principle of having the lowest timber raised 6 inches above the ground level, with building on a slab. Broken up paving slabs as a dry stone wall. Used car tyres filled with crushed hardcore, ballast, or shingle. Gabions. Your imagination is the limit. But avoiding an accessible void and creating a sump are fundamental.

Right ok - thanks Mike. As you can tell I have no building design experience whatsoever (Oh how I wish I'd tried harder at school!)

Sorry for asking, what would be the most cost effective way to achieve what I want?

My thoughts for recessed ground was to achieve 150mm gap between the bottom plate/joist frame and the ground, then 150mm joists so literally the step up isn't 300mm and the subsequent loss of eaves to floor height as I'm so tall - 300mm to floor level only gives me <2.2m then at the tallest part of the eaves so max floor to lower surface of the rafters would be 1.9m max before taking into account 18mm flooring - does that sound right? I'm 1.93m so if that's the tallest bit I'll struggle inside.

I still like the idea of piles, I guess blocks mortar in squares would be also be acceptable?

Thanks and apologies for lack of knowledge

BT

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[Mike G]

I've no idea. If you have a whole lot of paving slabs, then that would be cheapest. If you can get hold of some free car tyres, then you'd only need a few bags of ballast, or similar. I've seen heavy duty interlocking cellular plastic paving (you know the stuff, which they fill with soil and plant grass in, to allow car parking in fields) which strike me as a possible decent shed foundation. This one seems to have some sort of approval for use as a shed base). If you can get hold of some heavy duty sand-bags, fill them with sand or shingle, and pound them with a big tamper, then that would do nicely (you need bags which are rot and UV resistant). As I said, sticking to the principles then your imagination is your only limit.

Before you get too far with your design, though, go out and dig a hole 2 feet deep. Report on what you find.

 

[RogerS]

Do you have any scrap yards nearby ? How about a couple of lengths of old steel I-section on which to put the shed ?

 

[brokentechie]

I've no idea. If you have a whole lot of paving slabs, then that would be cheapest. If you can get hold of some free car tyres, then you'd only need a few bags of ballast, or similar. I've seen heavy duty interlocking cellular plastic paving (you know the stuff, which they fill with soil and plant grass in, to allow car parking in fields) which strike me as a possible decent shed foundation. This one seems to have some sort of approval for use as a shed base). If you can get hold of some heavy duty sand-bags, fill them with sand or shingle, and pound them with a big tamper, then that would do nicely (you need bags which are rot and UV resistant). As I said, sticking to the principles then your imagination is your only limit.

Before you get too far with your design, though, go out and dig a hole 2 feet deep. Report on what you find.

Excellent stuff thanks Mike.

I guess some photos of what exists may help so duly attached is the area I'm planning to site the shed.

I've also attached what's existing - the concrete/slab part spilt the garden in two across it's length so seems ideal, although the top part will be likely unused so I could put it there but I would like a vegetable garden at some point

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[Woodbloke]

This is how I did mine without going near a concrete base:



Lots of 'old skool', really thick concrete paving slabs to form a series of bases, over which sits some proper, creosoted railway sleepers, laid edge on. The 'shop is then built on top with DPC in appropriate places to keep out the wet stuff. The panels are marine ply, double glazed windows and the whole lot made water tight with a generous application of silicone sealent. Because I did a truly appalling job on the original roof, I had it professionally sorted out a few years ago.

Despite the somewhat 'Heath Robinson' approach, the 'shop is in it's 16th year of wood mangling production. It's completely dry, well insulated (too bloody hot in the summer) and doesn't suffer from any sort of condensation so I've never had to protect ferrous surfaces. There's also a lot of heavy, cast iron gear in there so provided you plan out the layout across the suspended floor, it's well able to withstand the weight - Rob

 

[Rod]

My shed is sitting on a base of concrete paving slabs on top of the underlying chalk.
The walls are supported on a 150mm high brick plinth and the floor is supported by rafters protected by a DPC.

Rod