Let the shed extensions commmence!

[FenceFurniture]

Research Sikens and Cabots.
I prefer an oil of some description because it moves and breaths with the timber.

Taking some offcuts to the hardware tomorrow to see what Minwax Decking Oil (Natural) looks like. The guy in that dept is an old-school painter and has given me very good advice in the past. He said to steer away from Sikkens because it will be a high wear work area and repairs to Sikkens mean doing the whole deck again, where an oil can be spotted to wherever required.

I've been very impressed with another Minwax product (PU satin interior on the floor of the shed), so this decking oil could be a good solution at a good price too. ~$50 for 3.78 litres and $100 for 10. Minwax is made in the USA and Home Hardware is owned by Woolworths, hence its presence in our market.

For the bottom and sides of the decking boards I'm now thinking two coats of Diggers Eco Whatsit (erzatz creosote). Water based, doesn't skin so the timber will breathe. I've used this 5 years ago for some garden trim boards and they are still in good nick (below ground is questionable but then so was the timber in the first place - old palings).

Have now finished milling the decking boards, sikaflex smeared on the ends and holes on top. Used it to fill a few cracks too. The Dark Amber (like a warm mid-grey) is a good colour that is not easily seen in blond or red timber.

[FenceFurniture]

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

Not much head room at all Chris - quite low in fact.

[Chris Parks]

It is possible to fabricate a beam using far smaller dimensions and come out with a way stronger result and it won't bend.

[rwbuild]

Brett
I will calculate the size beams you need tonight for you for the roof

[FenceFurniture]

Thanks very much Ray. I've subsequently realised that there will have to be three posts at the back (along the fence) because there will be a sheet of roofing metal running as a wall from the shed to the end of the deck. This will be from just below the beam down to about 750-800mm from there. It's to stop weather getting in that side. There will be a gap of about 300mm from the wall sheet to the fence, and so they will run in parallel for a depth of about 600mm.

The extra post will be needed to keep the metal rigid. That means the posts on that side will be at 1.8m spacing. (this is the southern side).

On the northern 3.6m run there will be the post at the shed, 2.4m to the next post and the last 1.2 of the roof/beam will be cantilevered.

I suppose that I could put the middle post on the southern side at 2.4m so that they line up, but it will have an asymmetric look anyway because of the cantilevered corner. And it would be best to have the post in the middle for maximum support of the wall sheet (I'll probably add some "purlin" equivalents to keep it nice and rigid).

[FenceFurniture]

This should give a clearer idea (refer attached). Olive green are the joists, and there are three doubles to accommodate where the deck boards will join so that the holes can be 20mm from the ends. There are four different length boards that i have to work arround: 750mm at the bottom left corner, 900mm right across the top, and 1050mm, 1350mm filling up the gaps.

The red boards are just for my indication (there's 3 red boards in each length).

[rwbuild]

Deck, piers under ends of each bearer and middle of each bearer
Ridge F11 KD hardwood 170x45,one end supported off existing shed, other end post off deck OVER pier
Pitching beam F11 hardwood 90x45 if using intermediate post above pier or 140x45 if clear span.
Rafters F11 hardwood 90x45 at max 900 centres.
NO snow loading calculated. If snow loading required, ridge F11 hardwood 240x45, pitching beam F11 hardwood 140x45 or 240x45.
All posts 90x90. Tensioned strap bracing 2 opposing on each side of roof on top side of rafters and 2 triple grips to each rafter at pitching beam. All beams to be bolted to posts, posts bolted to floor joists and bearer
Roof battens fixed to rafters with 100x14g batten screws.

The above is provided as advice only calculated from Smartframe software and is based on none standard industry drawings or architectural plans. You are advised to have all work certified by a structural engineer and approved by council prior to construction.

[FenceFurniture]

Thanks very much for that Ray. How could I estimate the F rating of 95x45 seasoned Tallow wood? I know it would depend on a great many factors (lack of splits, ¼ sawn or not, etc)

[rwbuild]

Industry standard aged seasoned hardwood is rated as F11 being free of knots, rot, shakes and major shrinkage splitting or defects.

[FenceFurniture]

Today I made a water level as per Chris Parks youtube post. Just letting the Sika Flex go off before I try it out - should be a bit of fun.

Also purchased the H3 F7 Treated Pine joists - they absolutely STANK of chemicals and insecticide and so did my hands after sorting through them to get nice straight ones with no knots blown out(note to self - always wear gloves when handling TP). There were almost nil ¼ sawn boards there and the one or two that I could see were at the bottom of the stack.

Where there will be a single joist they are 90x45 and in the three spots where I have shown a double joist they will be 90x35 (almost half the cost of 90x45) screwed together with a 5mm packer to keep the apart for water to drop through. They are double because I have set the countersunk holes in the ends of the boards 20mm from the end so as to avoid any chance of splitting these very brittle boards (because of their 60 years). Otherwise I'd have to set the holes 12mm from the edge and that would leave the perimeter of the CS hole about 5-6mm from the end of the board and there would be guaranteed chip-out which looks crappy and can lead to rot.

While I was at the hardware I managed to score a couple of skids - one from Merbau, and one from dressed pine - I could see an immediate use for the pine. So I also made a form for the bearer pads:



It will yield a pad 350x350x90mm, and the idea is to half fill it with concrete, lay the chook wire (fold it back a bit from the edges of the pad) and then lay the reo in a cross, fill with concrete. Should take about a 20kg bag I reckon.

I'll make a couple more of those, lay them in place, put a lid on them (sheet of ply or MDF) for using the water level. Set the fall so that any water sitting on the deck can run off in the right direction.

Where the post go, the pads will be 400x400 by 600 deep and will have a stirrup set into them. I'll taper these pads out to the bottom so that a yuge wind gust will have to pull a concrete wedge weighing ~100kgs out of the ground.

I also picked up 4 litres of Diggers Eco Timber Protecta (bitumen based but water soluble). The guy recommended that I get them to put it on the shaker at the paint section because it has a fair bit of solid matter. WELL DOES IT EVER! The shaking didn't make a blind bit of difference to the ~2" of hard packed sludge that I found at the bottom of the can (reckon it must have been on the shelf for "quite some time"). It took about 20 minutes to stir it to where I was satisfied, and even then there were still some pretty big sludge dags - when the level drops a bit I can give it a more vigorous stir and the second coat will have an even higher ration of solids. Then I gave the 4x3" hardwood bearers their first coat. Second coat tomorrow. Half of the bearers already had a genuine creosote coating so I just put the Diggers over the top of that. Can't have bearers that don't match colour. I couldn't bear the thought....

One last task on the bearers is to cut them to size (~1.5m each) which will leave a beautifully smooth surface from the drop saw, and then a bit more diggers over the end grain. The smooth surface is important because it significantly reduces the ability of the end grain to absorb moisture. I picked up on this fact when I was painting the ends of some green timber a while back - I noticed how on the super smooth surface the paint stood up on top of the surface (i.e wasn't absorbed into the end) whereas on the rough surface the paint all got sucked in. Something to do with a clean cut (rather than a tear) across the fibres and significantly less surface area according to John G. I'll do the same with the joists.

I have been considering using the Diggers on the joists as well - can't see how it can harm. I was interested to read on the can that it "helps seal in toxins for treated timber" and it's also water repellent, so I might just give them one coat (bearers will get two because they are closer to the ground).

Will also use the Eco on the underside and sides of the deck boards - maybe just one coat. Have put a smear of Sika Flex over the end grain of these boards and you can see a few of them in the top right corner of the pic above. Filled the bigger cracks in the sides of the boards and some of the cracks in the tops, plus all the larger nail holes, esp in the top.

If any rot shows up in this deck I'll be a little disappointed.....


So, all up a very satisfying day.

[Glenn.Visca]

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

Queensland timber used to have some good span tables on the interweb, including tables for cantilevered decks.

Let me know if you can't find them, I will see if I still have a copy.

[FenceFurniture]

Forgot to mention that the pine form has been heavily waxed so that not even the proverbial will stick to it. With a bit of luck I can just slide it up off the concrete pad after about 8 hours. If not (say it's tapered slightly) then I can just unscrew the boards and peel them off.

[Bushmiller]

Brett

I had missed this thread so thanks for the heads up.

Actually you have already had excellent advice supplied to which I can't add very much.

Just going back to the solar panels, I am putting up a set of four small (12VDC) panel to run a small pump. One face East, two face North and one West. They will all be mounted on a very shallow slope skillion. I have made up some timber frames to mount the panels on and they are hinged so I can adjust them for seasonal changes in the sun's elevation. This is to maximise their performance.

You may not be able to do that with 240V panels. You would definitely have to make up a frame in advance of the supplier coming along. Also it is a lot of fiddling......

With your decking treatment I would suggest that whatever you go with, make sure that you can apply it with a squige type applicator. Knowing your penchant for neat and tidyness you would then be able to re finish the deck every 6 to 12 months as neccessary and it might take half an hour. I believe there a great number of products you can apply in this way. I quite like the Organoil products ( I think the smell is my primary addiction) but by no means the only one you should consider.

As to the layout of your shed for machinery purposes just make it flexible. Plenty of power points. I saw that you have placed the Dusty in a separate encloure outside, which is excellent, but consider exactly where you are going to run your primary DC header pipework so it can easily reach to any point in the shed with off-takes. If you run an air compressor, you might want to consider placing that outside too, but separate from the dusty.

An exciting time.

Regards
Paul

[FenceFurniture]

The overhead beams for the deck roof will have to be made reasonably soon.

Am I better off using shorter rather than longer lengths? Is the length relevant to strength? The laminated beams that I see at the hardware are often composed of pieces no more than 300mm long, and are sold as F7 rating.

I have quite a stack of <=600mm lengths of hardwood which would be much easier to dress than the longer lengths (jointing anything over about 1200mm or so can lead to error). It also consumes the shorter lengths of timber which would otherwise only be good for noggings (and i have plenty of other stuff for that).

Is finger jointing the ends of each part necessary? Can I get by with glued butt joints?

[DaveTTC]

I cant claim to be an engineer but i do believe the finger joints add considerably to the strength over but joints.

I have made my own laminated curved beam at about 8m long but the average length was 2.4

Mine was 5 laminations at 10mm thick. Joints obviously stagered and piecesat the ends were remaining pieces of 2.4. Was an interesting exercise. Not sure how i will make a curved gutter. Mine was an 1/4 elipse curve.

Dave TTC
Turning Wood Into Art