Timber Base advice

[festive]

Looking at.building a timber workshop, I have built one before but that was on flat ground on hard pack stone mud Base.

This one is on a slight decline and the ground seems clay all the way very soggy In winter.

Base dimensions are 8m x 5m and I'm thinking of drilling piles and building it on stilts.
.
Would I fill with concrete and some rebar. Or timber posts into concrete.
What sort of spacing should I use i know depends on tImber but I thought of using 5metre lengths to keep it easy. Say I spaced each Pillar 2metres apart in a grid what sort of timber dimension would be recommended. Load wise will be taking a quad bike and sit on mower. Any thoughts appreciated I will add this to projects page once I get the spec sorted.

THanks in advance

 

[John D v2.0]

Pad foundations sounds not a bad idea, save on waste but still get down to solid ground. I'd not use timber somewhere that's permanently damp (close or below ground. I've thought a little about the topic as one day I'll do the same as you. Your main problem will be satisfying building control about the adequacy of any foundation. If you want to go off the traditional you'll probably need to do some calculations.
If you're doing it by hand how about a thin layer of concrete maybe 200mm, then cast a column or even just stack a load of concrete blocks on their side with mortar between. Then once you're up to ground level, you could get some cheap concrete lintels and span between the pads.
That way everything below ground is safe from damage, then you can start your timber on top.
Good luck, I'm sure someone more professional will be along soon!

 

[festive]

OK done some more research and Im starting to wonder if I did the right thing moving to a house sitting on clay.
Tried this site earlier http://www.labcnhw.co.uk/foundationcalculator

Fck me reckons I need to go 2.5m deep!

Jewsons have quoted me £1000 for a beam and block Base. But of course I need to seat it on something. Called a mini piling firm reckons 8 piles @ £300 each im sure ive seen these cheaper. So I'm looking at 3.5k just for a Base.

Seriously Im sure I paid this last time for the footings for the whole of my rear house extension.

Any thoughts welcome here seems a bit steep for a timber framed building?!

Maybe I need to go back to a timber Base but then I still need footings.

 

[motorbiking]

I'd be tempted to do it like a deck and just make a suspended, insulated timber floor. 2 x 6" joist on 4 x 4 posts spaced 1200mm apart with joists and beams as necessary? Approx £400 for the wood.

 

[festive]

ok thanks motorbiking. Timber Base possibly on my budget looks more viable.

Still can't find details anyone cheaper than some 3000 for 8 piles.
Found my local hire conpany can supply auger attachmeets for mini digger plus 1.5 ton mini digger for about 230 all jn for weekend. So with this im going to put some concrete piers into the 2metre deep holes.

 

[festive]

HI I have attached a few rough sketches for base any thoughts appreciated!

Intention is to hire digger 6inch auger go down 2metres fill with 1m ballast then concrete piers in.

Build timber base and bolt to piers using 2 x m120.

 

[motorbiking]

Personally, I wouldn't exceed 1.5M between posts, I think your centre and 8M run are a bit long at nearly 3 and 4m unsupported.

Also 8 x 5 is over the 30M2 limit allowed, so do you have your Planning and BC sorted?

 

[festive]

Thanks buddy yes reduced it to 6x5m as a tree was in the way. Going to take your advice and keep 4 across and add 4 across middle also so 12 piles, 1 every 1500 on 6m and 1250 on 5m.
Digger turning up tomorrow with 2 meter auger never used an auger before on digger.

Also this thinking of laser level to make sure all posts same height any recommendations for outdoor one?

 

[motorbiking]

What I'd do:

Make up the external parts of the frame "the box", attach at least 4 of the posts to the frame (the corners) drop them in the holes, prop them up with blocks or whatever from ground level until level, use a couple of standard beam levels to get the levels right on the long beams which you'll screw/bolt to the sides of the posts. Mix your post crete and concrete those 4 in, give them a good rodding to fill the air gaps, check the levels and gently tap down if needed, leave it a couple of hours (or over night), attached the remaining posts and fill.

Personally I think it will be friggin hard to get the post depth right for a level floor and you'll probably want them suspended and let the concrete fill the gaps. As long as you've got 4 set right the rest should be easy.

 

[festive]

OK so ive managed to build my base and upgraded timber sizes to 8inch timber across front and rear. Now im about to lay the floor joists with hangers. Im having a brain dullout. (fyi i drilled out 2 metre piles those 100x100 posts are 6ft down in concrete)
Q1 Ok im aware joists should be 400 centers, but im laying 18mm OSB sheet which is 1220 x 2440 right how does 400 go into 1220, im keen of course to get them right so i as i lay not cuts are required! OR close to. Also do i start my joist from center and work out to either end?

Q2 Also i read you're supposed to lay sheets across not inline with floor joists, the Span back to my first cross member is about 1910mm so am i supposed to add 'noggins' along this line so i in theory have 1220 and then 700 or go past and noggin at next 1220. Am i getting in a muddle here!?

Pic attached of my base so far, your thoughts very much appreciated as always.