Let the shed extensions commmence!

[twosheds]

Are you going to reuse the 'crazy cladding' that is on the back of the shed (shown in picture 4). I reckon you should, it gives it some real character.

Twosheds

[NCArcher]

Shhh. Brett's eyes are a bit wonky. He thinks it's perfectly straight. You should see some of his other projects.

[FenceFurniture]

Are you going to reuse the 'crazy cladding' that is on the back of the shed (shown in picture 4). I reckon you should, it gives it some real character.

Twosheds

Heh heh, yeah I like it too, but unfortunately it has to go. That entire wall will join onto the new shed.

[Chris Parks]

While we are telling war stories on excavation mine was 3.5 metres deep x 9 wide x by about 12 long by hand, all shovel, wheel barrow and jack hammer. It took 12 months to do as in those days the small machines did not exist and we couldn't get a big one in. Anyone who has been to my place will appreciate this, we put a snatch block on a tree down the back and ran a wire rope back to my driveway and hooked it up to a Forward Control Landrover (brother in law's) and after slabbing out large rocks with feathers and wedges we dragged the rock over the back fence into National Park. I wish I had taken some photos but I was too busy and too knackered to think about it. We eventually blew up the gearbox in the Rover and as it wasn't mine I had to fix the bloody thing.

[wheelinround]

While we are telling war stories on excavation mine was 3.5 metres deep x 9 wide x by about 12 long by hand, all shovel, wheel barrow and jack hammer. It took 12 months to do as in those days the small machines did not exist and we couldn't get a big one in. Anyone who has been to my place will appreciate this, we put a snatch block on a tree down the back and ran a wire rope back to my driveway and hooked it up to a Forward Control Landrover (brother in law's) and after slabbing out large rocks with feathers and wedges we dragged the rock over the back fence into National Park. I wish I had taken some photos but I was too busy and too knackered to think about it. We eventually blew up the gearbox in the Rover and as it wasn't mine I had to fix the bloody thing.

In those days who cared about photos just get the job done.

[FenceFurniture]

So, let's see what the Brain's Trust thinks of some of these ideas......

Bearers: onto concrete pads, and they will be from the stash of beautifully straight 4x3 hardwood from the bowling club. I can't remember, but I'll bet that many or most have been half creosoted (old style super dangerous Creosote). I'm thinking that it may be a good idea to use Erzatz Creosote for the untreated parts (you know, the new "safe" Diggers water soluble one). I've used that on some hardwood paling that were for garden borders 5 years ago and much of it is still in a good condition (some went onto timber that was dodgy in the first place, some has been walked on etc).

Joists: I plan to use new 4x3 (rather then 4x2) treated pine. There will be 8 joists 3.6 metres long so the difference in cost shouldn't be too much. The reason I lean to 4x3 is that I can then set the screws back 25mm or so from the ends of the decking boards - and I believe this will be a help. These boards, although dressed 4x2 Norfcoast Hardwood down to 95x45mm (mainly Tallow wood) are very brittle being 60 years old, and there are quite a few cracks that would love to develop. Some of them would not react to well to have a pre-drilled screw just 12-15mm from the end.

I am quite deliberately not using 4x2 Hardwood Joists (although free and straight) because they will have to be predrilled and there are too many residual nails that will create difficulties, requiring a second hole to be drilled through the deck and ending up looking like shight.

Should I put a little piece of Protectadeck between the joists and bearers? Not hard to do and I'll have to get the 3" version of it any way because the joists are 3" wide.

[FenceFurniture]

As described, 95 x 35 hardwood (yep, I know it's overkill - I LOVE IT!). This is a working deck that will have heavy machinery rolled across it and generally given a tough time with other work (splitting firewood is an example, but not the big stuff). I have now dressed all of the boards, and am just finishing off putting Sika Flex on the bigger cracks on the vertical faces, sealing off skewed nails holes etc.

The next step with these will be to put a 5mm roundover on each top edge, and then run a 3 flute bit across each side of the bottom face - like you get with proper decking timber so that it sheds water. The fluting won't go to the centre of the boards but I don't see that as necessary because the outer flutes will stop water getting to the centre of the face. I have to be very wary of nails near these routing edges and there are enough!

I plan to put a 3-5mm gap between the boards.

The ends will be butted up, and this brings up another question. rwbuild suggested that I smear Sika across the ends of the Cypress boards that I will use for the front external cladding (in another thread some months back). That was easy enough to do so the question is: should I put a smear across the end of each of theses decking boards? Sounds like a good idea to me.

Next: my overseer says I don't need to put any finish or seal on the sides or bottom faces of the decking boards. This doesn't sound right to me. You may remember I was discussing painting those three faces earlier in this thread. He says anything I do will be unnecessary and will be gone within a year or two. Hmmmm. I understand that an oil won't last all that long, but what about a coat of Sikkens - or will that do the same as paint, i.e, not recommended?

He also suggests just oiling the top face, which is easy enough to redo every 6-12 months. I have been thinking to use Sikkens for this which will give more UV protection, although at a cost of an orange tint to the timber, and significantly more $$$. Bear in mind that this deck will have a lid over it but not enclosed walla so it will cop some rain at the edges and a fair bit of angled sun in the winter months.

[rwbuild]

Sikaflex the ends of the boards, this is where the majority of any rot starts.

Oil the sides of your deck boards also, when you recoat after they are down you will get excess run down the sides anyway.

3mm gap blocks too easily with saw dust and fine chips, use 5mm and with a fitch brush you will be able to re oil the sides of your decking.

[FenceFurniture]

Oil the sides of your deck boards also, when you recoat after they are down you will get excess run down the sides anyway.

Are you saying it's unnecessary to oil the bottom face Ray? What oil would you recommend? The only outdoor oil I've used before was Organoil Garden Oil. It was ok I guess.

3mm gap blocks too easily with saw dust and fine chips, use 5mm and with a fitch brush you will be able to re oil the sides of your decking.

Exactly what i was thinking re the gap. This is another reason why Protectadeck will be important - there will be lots of sawdust gather in between the deck boards on top of the joists and that will be a lovely little moisture reservoir. Mind you, I do intend to sweep and blow out the dust

[rwbuild]

By oil I mean what ever you are going to use on the deck boards, I think you said Sikens. By all means do the bottom as well before you fix them down but the drip groove you are going to rout will do the job nicely.

[FenceFurniture]

I was thinking oil because Sikkens puts a skin on it then it which would be pretty much the same as paint, which was advised against earlier.

No? Does the Sikkens let the timber breathe enough?

[Sawdust Maker]

I've a smallish tin of oldish creosote if you want it

[rwbuild]

Research Sikens and Cabots. I think you will find the one you want or if you have used something in the past that your happy with, use it.
i prefer an oil of some description because it moves and breaths with the timber.

[FenceFurniture]

I have to do some research on the timber profile required for hardwood beams for the deck roof.

A Google search brings up quite a few hits, but they are mainly charts for proprietary brands of beams. These two beams will be Norfcoast hardwood (most likely ¼ sawn Tallow wood).

Beam 1: Will be supported at each end by a post, will be 3.6m long with no extra posts in the middle (although adding a middle post would be no big deal).
Beam 2: Will be supported at one end by a post, will be 3.6m long and instead of a post at the other end, the post will be 1.2m from the end so that the beam will be cantilevered. The reason for this is because a post at the end would be right smack bang in the middle of the walkway.

Other specs:
The deck will 3.6 x 3m (and the beams will run 3.6)
The roofing material will be steel roofing sheet
Gable roof pitched in the middle, ~20-25° pitch.

Current thinking is to laminate two tallow wood (60 years seasoned, nailed straight when green) 4x2 (95x45mm after dressing) into a 95 x 90mm beam. There would actually be four lengths of timber used to make the 3.6 m length (joints would be staggered of course). Titebond III (weather proof) and 75mm B8 coated bugle head screws for the beam assembly. They will be under the roof of course.

The only official looking site I've spotted is this one, but I don't seem to be able to see the info I need in there :
https://law.resource.org/pub/au/ibr/as.1684.3.2010.html

Does anyone know of a site that has perhaps more direct info or tables for span requirements?

[Chris Parks]

Try this, BTW how deep can you make the bearer, there are a number of alternatives if you have the spare head room.

https://www.google.com.au/webhp?sour...%20tables%20au