Thread: Shed build - waterproofing and slab?

Just spotted your reply.
You could use the aluminium foil flashing, but it folds a bit "wrinkly" and the low spots then collect dust and mud and water....
I had mine folded by a local sheetmetal place out of 0.6mm zincalume and it stays nice and straight. Whatever lands on it get blown or washed off. It wasn't expensive at all. I had it folded in 2.4m lenthg and joined them by overlapping about 20mm with a smear of silicone in between. No other fixings. There were a couple of spots where the slab edge was a little warped and I had to pop rivet the flashing on to the inside of the cladding to keep the inside flange upright.
Good luck.
Joe

PS: your drwaing seems to show your wall sheet as a thin line. Isn't it corrugated or whatever? In which case the 20mm are taken up by the corrugations, aren't they? That's what I drew, not some dort of 'thick' wall sheeting.

Originally Posted by jhovel

J

PS: your drwaing seems to show your wall sheet as a thin line. Isn't it corrugated or whatever? In which case the 20mm are taken up by the corrugations, aren't they? That's what I drew, not some dort of 'thick' wall sheeting.

Yeah it is corrugated. I've provided a top view to show how it will sit give or take some millimetres. I guess most the sheet will be 20mm in from the edge with a corrugation popping out every so often.

Also how did you secure the flashing to the slab and sheet? Did you screw it into the sheet or slab at all?

Sorry but I have another question. In your picture the flashing that sits on the floor is angled. Is that actually how it is or would a 90 degree bend be okay?

I've designed the flashing I will need. 70mm agaist the sheet + 30mm + 30mm. All up 130mm of sheeting in width. I will need roughly 20 meters length.

I recieved a quote from one place of $6 per meter length + GST for colorbond flashing. Does this seem reasonable? how much should it cost?

Sounds OK for price. My flashing only goes up the inside of the wall by about 20mm.... Why do you plan to go over the edge of the slab by 10mm (according to the previous drawing)? It gives easier access to critters... more difficult to seal if you have an ants nest nearby etc.
Are you planning to seal/paint the floor? If so, do it before putting the shed up. You could do the final coat once it finished.
Once the wall are up, you could run a bead of silicone around the bottom edge and seal the flashing against the slab. That way even a sheet of water running around the outside won't come in (has happened to me 4 times now - the muddy water makes a hell of a mess).
I'm planning to seal mine when I paint the floor - I haven't because the shed is now full and it's a bugger of a job once you put things in the shed. MUCH easier without the shed there
Joe

Originally Posted by jhovel

Sounds OK for price. My flashing only goes up the inside of the wall by about 20mm.... Why do you plan to go over the edge of the slab by 10mm (according to the previous drawing)? It gives easier access to critters... more difficult to seal if you have an ants nest nearby etc.

Joe

Cheers for your advice.

After some measurements I found out the slab edge is 30mm is some places. I thought it might be best to have some give. Also the corrugated parts of the wall sheet protrude 28mm so having a 30mm edge to sit on will work nicely. I thought if there was any gap I could bend the 30mm flashing inwards towards the slab. The gap at most will be 10mm in some places.

Also I've decided to have the inside wall flashing 70mm which will reach the bottom girt. I will screw it in place with the sheeting and will be neat tucked away behind the girt.

That makes sense! A much better solution than mine.
Take a picture when you've installed it. Be of interest to more than just me, I'm sure.
Joe