Shed slab construction

[DC3]

Gday all.As noted above,new to this forum & came by it purely by looking for answer/s to proposed shed slab construction. I live in Sydney but have some real nice bush acres about 3 hrs inland from Brissy.My intention is to erect a 9m x 6m x 2.7mH or such like shed.Quite heavily treed but have contact for local to clear suitable site.So situation is this: as the land is near as level can be is it recommended to have a perimeter edge that the base will snuggle up to or add suitable edging/flashing to prevent water/dust from entering inside? And probable slab cost. Considering a DIY farm shed which in looks resembles a double garage with enclosed lean-to.Thanks dc3

Copied from the G'day forum.

[Random Username]

The slab should be installed so that the sides of the shed (assuming colourbond) don't come in contact with the ground and aren't going to have water ponding against them. Check the detailing here - http://www.cadtech.com.au/Products/STRAMIT/architectural_detailing_guide.pdf

[Bloss]

The shed suppliers will all have specs for slabs to suit their sheds and most will have drawings or pics too. It is easy to seal between cladding and slab when the slab and shed have been constructed according to plan - and what is best depends on what cladding and the design of the cladding/ slab junction.

The slab should have builders plastic underneath and with sufficient allowance to come up past the top of the slab at the edges. The cladding goes down the outside usually to a minimum of 50mm down from finish of the slab top. There are more complex ways to ensure water & dust proofing such as a rebate in the slab edge, the addition of flashing and so on. The last step would then be the use of a sealer- and again that might be expanding foam, or a flexible filler of some sort.

In any case with a flat site you need to make sure that you grade the shed surrounds from the slab edge out to direct all water away from the shed. That might mean you need drains, but could be simple grading of the soil and grass, or roadbase, or pavers or concrete - whatever you want and need around the perimeter - but in all cases so water flows away from the slab edge.

But the start is to select the shed then read up on what they recommend for the slab - water proofing starts with good design then build - dust can be sealed out after for the most part. The harder parts to seal for dust will be at the roof/wall join and and the large openings.

[DC3]

Well, can`t complain about the service.Quick responses (thanks guys) & got what i needed to know. Drainage will be old school flat V shape -angled bricks on sides,and flat on base. Saw that on an old miners house down Denny way & still works a treat after all these years.Now that i`d forgotten about until Bloss` reply which jogged the memory.I also like the idea of a formed flashing which directs water away (& into a drain) as per link given.Colourbond is the preferred material & there`s many & varied designs/configurations which i`m pretty sure i can tackle being an ex sheety. Ta, DC3

[Oldsaltoz]

As Old chippy said,

a simple rebate right around the slab means the cladding will end below the floor level and sit on a ledge that is dead easy to seal. The extra cost will be minimal as it's just a matter of nailing a strip of timber on the inside of the shutters.

Good luck. :)

[DC3]

Thanks Oldsaltoz. Sounds good to me.

[SilentButDeadly]

Our shed got made on a level-ish site with a steel portal frame (each portal enacsed in 800mm concrete footings) and was sheeted to within roughly 50mm of ground level. 100mm concrete slab was then formed and poured internal to the shed. So the sheeting acted as formwork. Worked a treat. Been there since January 2006.

Concrete dude also cut crosses in both 6x7m sections of the shed using a diamond blade on a circular saw to provide potential crack lines if the slab moved or settled.