Workshop Floor

[Mcluma]

You need to start at the bottom

100mm hardcore - compacted -
sand 25-30mm - compacted -and as flat as a pancake - this is important otherwize your celotex isn't properly supported
membrame
celotex 100mm
reinforcement (rebar)
150mm concrete

make it lovely wet so it goes in easy and leveling is a breeze

I normally have no leveling to do at all - but you to do tamping to get air out and the water to the surface

When you order the concrete tell them its for a garage then they will make it more stronger

success

 

[Dibs-h]

You need to start at the bottom

100mm hardcore - compacted -
sand 25-30mm - compacted -and as flat as a pancake - this is important otherwize your celotex isn't properly supported
membrame
celotex 100mm
reinforcement (rebar)
150mm concrete

make it lovely wet so it goes in easy and leveling is a breeze

I normally have no leveling to do at all - but you to do tamping to get air out and the water to the surface

Agree

When you order the concrete tell them its for a garage then they will make it more stronger
success

Disagree - always spec the concrete. RC35 in this case. Spoke to my tame SE today and he states that for floors over 6", RC35 is required, when reinforcement is used. For < 6" could easily use RC30 as well - worth getting a price on both.

Dibs

p.s. When doing my build, one of my SE chums - stated that bringing the "fat" to surface reduces the structural properties of the concrete and one should only do enough tamping\vibrating to release the air and nothing more.

 

[Lons]

You need to start at the bottom

100mm hardcore - compacted -
sand 25-30mm - compacted -and as flat as a pancake - this is important otherwize your celotex isn't properly supported
membrame
celotex 100mm
reinforcement (rebar)
150mm concrete

make it lovely wet so it goes in easy and leveling is a breeze

I normally have no leveling to do at all - but you to do tamping to get air out and the water to the surface

Agree

When you order the concrete tell them its for a garage then they will make it more stronger
success

Disagree - always spec the concrete. RC35 in this case. Spoke to my tame SE today and he states that for floors over 6", RC35 is required, when reinforcement is used. For < 6" could easily use RC30 as well - worth getting a price on both.

Dibs

p.s. When doing my build, one of my SE chums - stated that bringing the "fat" to surface reduces the structural properties of the concrete and one should only do enough tamping\vibrating to release the air and nothing more.

Absolutely spot on =D>

You want it wet enough to flow, ( Make sure it is specified as that and not just add water on site which weakens the mix),which will allow minimum work in leveling and tamping. tamping or vibrating gets the air out, a float finish (if desired) brings the water to "cream" the surface and give you a finish. Personally I'd want my workshop floor to have a smooth finish which could be sealed and painted later.

I'd suggest that 9mm welded mesh reinforcement is plenty strong enough but you could go to 12mm if you want.
Either way - that's one hell of a good floor.

Bob

 

[Bongodrummer]

I'd suggest that 9mm welded mesh reinforcement is plenty strong enough but you could go to 12mm if you want.
Either way - that's one hell of a good floor.

:lol: Sam my wife just read that over my shoulder, and proclaimed, "YEAH! One hell of a good floor, that's what we want damn it!"

 

[Lons]

:lol: Sam my wife just read that over my shoulder, and proclaimed, "YEAH! One hell of a good floor, that's what we want damn it!"

B***** should have written in a disclamer I see a claim for damages coming on :shock:

Word of advice - don't allow the boss to look over your shoulder - switch off / close the lid - whatever! She might imagine you're viewing porn, could even start checking your phone and emails 'cos she might suspect you're doing "a Ryan Giggs" - but can't be worse than the alternative you've just experienced :lol: :lol: :lol:

I'd better explain that I'm a builder so work at home has a low priority. Taken me the last 2 1/2 years ( and still counting) to build an extension. New kitchen has been stacked up since December and only this week made a start. Will be done on a piece meal basis so loads of ongoing mess, dust and disruption. Just as well my wife has the patience of a saint. :wink:

Bob

 

[Bongodrummer]

100mm hardcore - compacted -
sand 25-30mm - compacted -and as flat as a pancake - this is important otherwize your celotex isn't properly supported
membrame
celotex 100mm
reinforcement (rebar)
150mm concrete

make it lovely wet so it goes in easy and leveling is a breeze

One question: what do we mean by hardcore? Are we talking gravel here? A certain grade of scalpings? or what?

We have plenty of shale knocking round, and the floor as it stands, has had a scraping/rough levelling with a mini digger, leaving bare shale. If this was compacted down would we still want the 100mm 'hardcore'?

 

[Dibs-h]

It's commonly referred to as MOT 1 or MOT.

http://www.smithsbletchington.co.uk/ind ... iew&id=101
http://reviews.wickes.co.uk/9987-en_gb/ ... eviews.htm

just to give you an idea - ring round for prices. I pay around £25 per bulk locally.

HIH

Dibs

 

[Lons]

Builders merchants might refer to it as hoggin, crusher or dolomite (yellow). Hoggin you would specify as say 20,40 or 80mm down to dust depending on the job.
If buying more than say 10 tonnes, it will be much cheaper to buy a bulk load from a quarry. 20 tonnes will be even better value if you can use it as a major cost is transport.

I doubt you would get away with shale on a dwelling but under a workshop floor??? You would know whether it's solid enough for you to be happy with.

Bob

 

[Steve Maskery]

I'm following this with interest, as I'm planning (head-planning, not paper-planning, yet) my next workshop. My current one has a concrete floor, but it is eroding in places, particularly where I wheel my TS about.
I was thinking that my next one will have a wooden floor. Is there a way of making the surface wooden but not springy?
S

 

[condeesteso]

re insulation - I'm not tech enough on this subject to know the structural / loading issues, but insulation would be a must for me. They use some kind of polystyrene sheet under concrete in houses?? but 500kg loads may be an issue. BUT the other point is damp membrane? - I am sure that it is impossible to make a workshop too dry (in the UK anyway) - moisture levels always an issue, esp in winter. So anything to make it as dry as poss is important I think.

 

[Mcluma]

I'm following this with interest, as I'm planning (head-planning, not paper-planning, yet) my next workshop. My current one has a concrete floor, but it is eroding in places, particularly where I wheel my TS about.
I was thinking that my next one will have a wooden floor. Is there a way of making the surface wooden but not springy?
S

To overcome this

have a nice smooth garage /concrete floor and put pvc tiles on it. these are industrial and are anti fatique and can hold weight over 1 ton, so no problems with wheeling the tools arround. they are interlocking so easy to lay down, they are water/oil and dust proof

 

[Dibs-h]

For a smooth surface - how smooth does a power float get it? Not meaning to hijack the thread - for my new garage floor, I am thinking about tiling the floor, which would be a damn sight easier if it was level and smooth.

Cheers

Dibs

 

[bosshogg]

I'm following this with interest, as I'm planning (head-planning, not paper-planning, yet) my next workshop. My current one has a concrete floor, but it is eroding in places, particularly where I wheel my TS about.
I was thinking that my next one will have a wooden floor. Is there a way of making the surface wooden but not springy?
S

Steve...put in a floating floor on top of your concrete one...seemloles_chk :lol:

 

[Harbo]

In this part of the world hoggin is an as-dug material and can contain clay which can get a bit messy when wet.
Crushed rock scalpings with some dust is much more stable and easier to handle if the weather gets bad.
It's angular and with the dust goes down very hard and rigid.

Polystyrene is very strong in compression but keep it away from diesel!
Providing it is restrained it will support very heavy spread loads - it is used a lot in Highway Concrete Bridge construction.
The suggested RC slab will certainly spread the loads. Concrete is weak in tension but strong in compression - the bottom layer of mesh is providing the strength as its under tension, the top layer mainly as anti-cracking (shrinkage etc.)

With the right concrete mix and power floats you can achieve a mirror finish.
Don't forget a spray applied curing membrane - prevents rapid drying of the surface and prevents hairline cracks.
You could use wet hessian or polythene sheeting but that would mark your surface.

Rod

 

[bosshogg]

Bongo,

Re all the info that your getting, which I have to say is good, but you should try and concentrate on one system and one only, the choice of course is yours for the choosing. One thing Iv'e not seen so far is any mention of expansion joints, I have no idea the size of floor area you are attempting to pour, but you will have to include an expansion joint around your perimeter where you are meeting up with the existing walls, in the trade we normally use a 12mm bitumen fibre board which should be available from any builders merchant in your area

. Assuming your not covering the perimeter abutments you can also get a polythene joint sealer, that would go for the longest straight run also, if say it was 5meters one across the middle will do. You can cut an expansion across the middle with a Stihl saw but you have to make sure this section has the steel reinforcement stopped back before pouring, this is then filled with a polysulphide joint sealer, it's not as good, in my experience, but it does work...bosshogg

You can't help a man who doesn't tell you what he wants

(homer)

 

[Bongodrummer]

Hi guys, thanks for all the input here, much appreciated.

Good point about the joints! The floor area is about 43sq metres 7.4m x 5.8m, though we may end up laying more in a bay in the front of the barn that leads to the proposed workshop area, if so that would be another 4 x 4m. Is that likely to need expansion joints 'mid slab'? When I get home I can post a diagram view...

So insulation is sounding like a very good idea, given the difficulty of a retrofit.

So far I think the spec is looking like

100mm compacted MOT grade 1 scalpings
30mm sand blinding layer, well compacted and flat
damp proof membrane
100mm celotex
Steel reinfocment grid - may be going for 8mm, as builder says he already has some which will be cheap, if not 9mm - each grid overlapped approx 300mm and spaced 50mm up from the insulation. Leave room for possible expansion joints in the steel (did I understand this right?)
150mm C35 concrete with fibres (A 12mm bitumen fibre board expansion joint round the edge, to the block wall)
float finish (possibly power float?)
Spray applied curing membrane.
cure.
Add possible expansion joints with still saw and seal.

Thanks, B.

 

[Lons]

In this part of the world hoggin is an as-dug material and can contain clay which can get a bit messy when wet.
Crushed rock scalpings with some dust is much more stable and easier to handle if the weather gets bad.
It's angular and with the dust goes down very hard and rigid.Rod

Hi Rod - that's interesting to know. it's the old story of being careful what you ask for without clarification.
Cretainly wouldn't want clay or other contaminants in with the stone.

Your scalpings is presumably what we would buy here as "crusher" which is usually 20 or 40mm - dust.
I've used hoggin many times and never had clay among it so obviously different in this part of the world (or I've been lucky). Had 30 tonnes just last month - not as good quality or as well graded as crusher but ok.

cheers

Bob

 

[Harbo]

Bob just to clarify the Hoggin from this part of the world originates from old river beds and has rounded aggregate with differing proportions of clay fines/silt.
Fine when dry but when wet can get very messy.
Having said that a prized Hoggin (and getting scarce?) around here is called Romsey Gravel - it has a fine aggregate mix and much sort after in Conservation areas to give the authentic rustic gravel path look.

Most of my experience is in building Highways and their associated infrastructure and the preferred choice of materials has changed frequently over the years. One thing that has never changed is the preferred use of MOT/DOT Type 1 Sub base which is a graded scalpings/crushed rock dust mix.

Rod

 

[Bongodrummer]

Hi guys,
So here is a rough diagram of what we are planning. The concrete floor will extend out under the base of the straw bale infill wall, providing a 'foundation of sorts. Given the lightweight nature, large surface area of straw bale, and that it will not be load bearing, we have been advised that this will not need any special foundations and can rest on the slab. We are planning a 2 bock high wall for that to sit on (just to minimise any possibility of damp getting at it (not shown).

So anyway, for that area (6.3x7.9m) how many expansion joint will we need? This datasheet (http://www.nrmca.org/aboutconcrete/cips/06p.pdf) seems to be suggesting that we want a joint at least every 4.5m, which would be a bit awkward because the bays are 6.3m. So looks like we are talking about splitting it into 4 sections of 3.15x 3.95m
My concern is that 4 isolated concrete slabs will not be so effective at supporting the heavy machines and absorbing vibrations etc. Are the expansion groves 'all the way through'? Should the steel mesh be continuous or arranged so that there are breaks where the joints will be? Any input most welcome on this most welcome!

 

[bosshogg]

Rod[/quote]

Hi guys,
So here is a rough diagram of what we are planning. The concrete floor will extend out under the base of the straw bale infill wall, providing a 'foundation of sorts. Given the lightweight nature, large surface area of straw bale, and that it will not be load bearing, we have been advised that this will not need any special foundations and can rest on the slab. We are planning a 2 bock high wall for that to sit on (just to minimise any possibility of damp getting at it (not shown).

...bosshogg