20x12 workshop base building, proposed method.

Joined
30 Jul 2008
Messages
256
Reaction score
5
Country
United Kingdom
i'm going to ramble on a bit here, stick with me if you can offer advice or tips please.
I have 3yrs ago built from scratch a 16x8 garden shed and that one I put ex council paving slabs down on a geomembrane, then concrete blocks to level the sloping site. I had a fair bit of well seasoned 4x4 timber which I used to make a base frame resting on the blocks then I put 18mm ply sheets down on the timber to make a sound base to work from.

View media item 8545 View media item 8546 View media item 8547 View media item 8548
12mm ply for the back and sides, osb for the roof, made my own doors and clad the front. I only got 2/3 of the shed as the kids wanted a play room, hence the 2 doors. The final materials bill was around £700, I was surprised how quickly it mounted up and how little room I had for myself.

So I have been looking to build another larger one just for me!
The local workshop supply companies seem to be having a hard time and are doing 20% discount meaning I can pick up a 20x12 workshop made with good materials for under £1500 supplied and fitted to my base work, bearing in mind the time end effort it took me last time this seems like a deal I shouldnt miss.
The area of garden I want to put this new workshop onto is not flat, there is a change of level in both directions. Concrete base is a non starter as its 180ft to the road from the site making the cost just too high for me.

I have stacked at the end of the garden a huge supply of 2" blue band galvanised gas pipe and a large selection of 2" Tube clamps like these.

View media item 8557 View media item 8556 View media item 8555
My garden is heavy clay about 1 spit down and my intention was to lay around 16 council 2" paving slabs level on the clay with tube clamp base plates sat on them, A vertical length of 2" tube to level and a horizontal frame of tube joined with 4 way crosses to make an extremely strong free of cost base that I can easily adjust to get level while building it.
This kit is sitting doing nothing now having been part of a very large climbing frame and swing area I built when the kids were smaller so I would like to use it.
I have some treated 4x2 timber which I would then lay on top of the raised tube bed which would end up looking something like the frame base from the picture above, just a bit bigger!
I am btw happy to have a workshop thats likely due to levels be around 12" off the ground at the doorway.

Now the workshop does come with a base/floor thats 19mm T&G boards on 38x75mm floor joists at 600mm centers which I could get them to place directly onto my 4x2" frame.
But...I do happen to have a pile of 2 and 3mm 8x4ft sheets of alloy 5 bar treadplate tucked away up the garden.

View media item 8563
I was considering using these sheets for a workshop floor, screwing it down directly onto my 4x2" base frame and getting the fitters to build the workshop directly onto this saving me the cost of their supplied base/floor but I wonder if it will make the workshop a bit cold and maybe prone to a damp floor due to temperature changes?

If anyones got this far ;) wadya fink?
 
Sponsored Links
I would go with a timber floor every time for a workshop. It is much more forgiving on your tools if you drop anything as opposed to a metal plate floor. I also think in terms of comfort it is easier to stand for long periods on a timber floor than a profiled metal floor. It does sound daft saying that but you would notice it. Also if the workshop is unheated having a cold floor may not be great for condensation.
 
OK, so I had a rethink on the workshop base, the alloy 5 bar treadplate sheets are now up for sale and so is the scaffold tube and key clamps as I have gone for a wooden base frame instead.

First I had to have a bit of a clear up where the new workshop is to be sited, The conifers needed to be trimmed some, a holly stump to go and my piles of tube, alloy sheet and timber needed to be moved.

View media item 9082
And after the big tree topping and clearup the site is ready for a base.

View media item 9083 View media item 9084 View media item 9085
As you can see below my garden slopes downwards away from the hedge in both directions towards the lawn and old pile of concrete posts where I had till recently a greenhouse which has now found a home in another part of the garden.

View media item 9086
So after a mid week delivery of lots of 4x2 and 4x4 treated timber, 400kilo of postcrete, 4" screws and big bolts its down to assembly.
A bit of soil needed shifting from under this frame to have half a chance of a workshop that didnt need a ladder to gain access to but here is half the 20x12ft base squared up and aligned ready for leveling and the 4x4 post holes digging.

View media item 9087 View media item 9088 View media item 9089
Last picture shows the 2nd frame, another 12x10ft which will butt up to the first once its been postcreted to give the required 20x12 overall size.
Now its fit the cross rails, make sure its all still level and move on to do the same with frame two.

View media item 9092 View media item 9093 View media item 9094
Nearly done now...

View media item 9095
Finished at last.

View media item 9096 View media item 9097View media item 9098
I am half tempted to put 18mm ply sheets down on this base and have the workshop built direct onto that but as the supplier will only reduce the price by £90 if I dont have his supplied 19mm t&g floor and bearers its more cost effective to go with his floor.
The white double glazed frame in the pics is one of two I have to fit to the building once its erected.
You will notice the front of the frame is quite a way off ground level, I do intend to have a decked area in front of the workshop, so once thats done the step up wont be quite as dramatic as it looks right now.
 
Anyone have any thoughts/suggestions on the area around the posts, the ground slopes so even with guttering both sides of my workshop there will still be an amount of water run off from the conifers etc that will maybe puddle on top of the postcrete around the supports. With the amount of free air that can pass under the workshop should I worry about rot just above the postcrete?
I would guess that mostly it will stay dry under there.
 
Sponsored Links
Sounds like a plan Coljack, have you or anyone reading actually used the product on treated timber? Reading the specs it suggests a primer is to be used first on porous materials.
 
Time for an update on this workshop project.

Got rid of the row of trees I had by the fence to give me some storage room tucked away behind the new workshop.

View media item 9083 View media item 9775
Used my new Evolution Fury circular saw to cut some alloy 5 bar treadplate to hopefully stop both little fury animals and the surface rainwater from getting under my basework. Buried the plate some inches into the soil.

View media item 9774
Some tool that is, made light work of the 2mm treadplate.

The new workshop arrived on a flatbed truck, first the floor sections went down, they had to add some extra bearers as their joins were not on my existing bearers. Now had they said I could have made sure I had mine in the correct place...

View media item 9776
Up went the 2 ends and the section with the door in it.

View media item 9777 View media item 9779 View media item 9778
I'm going to need to trim back that hedge some more as its pretty tight to the back of the workshop.

View media item 9780
All the sides done and its up with the roof trusses

View media item 9781
Roof sections next

View media item 9782
Glazing and felt.

View media item 9783
All done, with a few minor hickups like the trusses were not all the correct size :rolleyes: and the floor was too long by 1/2".

View media item 9784
Problem is it looks ugly (wife hates it). ok I have yet to figure out what to do about decking at the front so we can get in without a pair of steps. I have a double glazed unit that I may offer up to the front to see what it looks like, its the same width as the 4 panes and 12" deeper.
My next task is to figure how to put gutter on it, the door is 6ft and leaves no room for guttering under the eaves.
Perhaps I should raise the roof some at that side of the building? Must admit I never thought of the guttering when I asked to have the door there, the manufacturers didnt say anything either.

Anyone want to sketch me up an idea or two for making it look prettier? :)
 
pegs in the foreground are for what? decking?

Sharp eyes ;)

Yes they are height markers, as the older shed on the left is at a lower level in the garden I wanted to be sure of how high I could go with decking and still open the fathest door. The plan was to have decking out 1.8mtr from the front of the new workshop right across the width and shiplap the gap down the front of the new workshop to meet it. Then a step into the workshop.
Wife has now decreed that the decking needs to be bigger :rolleyes:

It will now be L shaped coming out from the pink wall in the old shed to meet the pegs about mid grass area. Around another 5.5 sq mtrs.
 
A nice weekend means the decking is now just about finished, still got paving to do in the small area to the right of the L shaped deck and I need to shiplap the front bottom of the workshop wall, the bit of deck there at the moment may go, not sure if I like that there but it keeps the cats out from under the shop for now.

View media item 10706
Edit: Just a thought for those who have experience of decking, I allowed a 3mm gap between the 150x32mm deck boards, tried 5mm and didnt like the fact I could easily see the weed suppressor below.
Where the 45 deg boards meet the framing boards around the outside edge should I have left an expansion gap? I have them flushed up to the framing boards atm.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top