suspended floor for workshop

[mpooley]

suspended floor for workshop

Ok i know i should use 8x2 but wanting to save money (workshop will be 15mtrs by 5 ) i aim to use 4x2 's
Now i am going to support these every meter accross the width of the floor so i reckon it will be strong enough?

so looking at the price of 4x2 i see the 4.8 mtr lengths of CLS timber is about a third the price!! so being really mean i'm thinking of using this instead.

bearing in mind i'm supporting each joist every meter do you think it will be ok???

joists will be at 400mm centres and covered with 18mm chipboard flooring BTW

thanks

Mike

 

[OLD]

Yes
http://www.diydoctor.org.uk/projects/lo ... _walls.htm
Looking at the above tables you may be able to increase your proposed span. But i would use treated timber with a dpc to the slab.

 

[mpooley]

Yes
http://www.diydoctor.org.uk/projects/lo ... _walls.htm
Looking at the above tables you may be able to increase your proposed span. But i would use treated timber with a dpc to the slab.

Thanks
But I didnt see any reference to the span in that table? just a "maximum span" ?
in a well ventilated subfloor do you realy think i need treated timber?

many thanks
Mike

 

[OLD]

47x97 at 400mm space max span for 1.5kN/sq m is 1.92m your proposed span 1.0m so almost twice the spec.
concrete is not waterproof so dpc required, treated all or local desirable drainage of the area is a factor.

 

[Freetochat]

Leaving aside the joists, I would be a little concerned using chipboard favouring WBP 18mm plywood.

 

[llangatwgnedd]

On the ground floor of my thirtys house is 4x2 with a five foot support

 

[martlewis]

Leaving aside the joists, I would be a little concerned using chipboard favouring WBP 18mm plywood.

I have chipboard loft flooring in my shop, the stuff which interlocks together. Takes the weight of my cast iron t/s being wheeled around with absolutely no damage. I do have joists every 12" and a subfloor of t&g as it was an old shed base converted!

Wouldn't trust the chipboard alone straight onto joists!!!

 

[mpooley]

Ok I'm sorry i'm an silly person! I totally misread the table!!!! ooops!

So the consensus is that 4x2 will be ok (i will be using dpc where necessary) but my original question was will CLS timber be as good?

also now you all reckon tongue and grooved chipboard not good enough for floor? oh dear more expense lol

thanks
Mike

 

[Johnboy]

I have tongue and groove chipboard flooring (the water resistant stuff) in my workshop and it is fine. My shop is 20" x 12" with the floor joists at 16" centres. Been down 5 years now, no flex and has withstood the machines being wheeled and dragged around OK. Surely with ply you will not have the T&G and get flex at the joins?

John

 

[OLD]

I notice expense is a factor have you costed a concrete base you could clean and use the shuttering in the construction. You will require lots of 4x2, slabs, beading for slabs etc (lots of work lining up the slabs)against poly sheet and ready mix & some threaded rod might be worth looking at.

 

[mpooley]

I notice expense is a factor have you costed a concrete base you could clean and use the shuttering in the construction. You will require lots of 4x2, slabs, beading for slabs etc (lots of work lining up the slabs)against poly sheet and ready mix & some threaded rod might be worth looking at.

I'm reckoning total cost of workshop to be £10,000.00 eek! :shock:
due to sloping ground a slab would cost a fortune! I would rather go with a slab as its much easier but would cost a lot more!
I'm using old rubbish scaffold boards for the shuttering so most i will burn when finished - but i know you can use a releasing agent on the shutters anyone one know what i could use?

Mike

 

[OLD]

If you are spending £10k the cost of treated timber for a base you will not be able to get at should not come into the equation .
A sloping site will have to be leveled with say excavation and/or stone fill this is the same for both methods.
The poly under base and up the sides gives a release when striking shuttering. If you use 8x2 it makes top and bottom plates for the wall studding.
Base 4'' at edge 3'' main field on plate vibrated site, threaded rod embedded to fix bottom plate via dpc, troweled smooth or covered in chipboard

 

[mpooley]

Yes I can see your point but i have overcome the sloping site by having deeper foundation at one end eg coming out of the ground at one end by 500mm so a suspended floor will be much cheaper from this point as a slab would be very thick at one end.

I am taking your advice and ordering treated timber just to be on the safe side but i must admit i'm not all that convinced. The underfloor will be dry and well ventilated and i've seen many a very old floor still in perfect condition. I think it would safely see me out anyway LOL

thanks
Mike

 

[woodbloke]

I have a suspended floor of 3x2" with sleeper wall at 6' (20x12' workshop) with 18mm chipboard/hardboard over the top. This is more than adequate to support my machinery and gubbins (some very good data in Jim Kingshott's workshop book on floor loading). That said all my equipment is fairly light (Kity stuff) though I have put additional support under the floor where the machinery is located - Rob

 

[Shultzy]

Mike, can you post a picture or drawing of the site, I might be able to suggest a cheaper alternative.

 

[mpooley]

Mike, can you post a picture or drawing of the site, I might be able to suggest a cheaper alternative.

I've already done the shutterring ready to pour (i'm waiting till friday for better weather) so i doubt if i'll change it now.
Basically what happened is the digger griver dug a huge hole and filled it with rubble from an old outbuilding at least 500mm deep and then rolled it and blinded it - i was ayay at the time and he made a complete mess of it!! its not level at all and the only way i can see round it is to raise the concrete footing out of the ground by 500mm at one end. so the footing will be 500mm at front going down to 25mm at the back but at least it will be level.

Mike

 

[OLD]

I am completely confused so like the 'dragons' say i am out, you need a builder it will cost you less in the end.

 

[mpooley]

Ok If anyone is still interested this is the front of the site this is the bit that has been shuttered up above ground level

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[mikeZ]

Have you considered Beam &Block floor on a perimeter foundation wall?
Cheers,
Mike z

 

[mpooley]

Have you considered Beam &Block floor on a perimeter foundation wall?
Cheers,
Mike z

mmh! No I hadn't !
I'll look into it on monday.

Thanks!

Mike