Lean-to greenhouse: Would 38 x 38 sawn timber be strong enough for frame?

It will have horticultural glass 457mm x 610mm.
Approx dimensions Width 1.4m x ridge height 1.8m x depth to wall 0.65m.
I can add stifferners as required. This will lean to a brick south-facing wall.
38mm x 38mm is readily available in 2.4m lengths from Focus, where I can get a 15% discount for the next week or so.
MM
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On Fri, 19 Mar 2010 14:38:18 +0000, MM wrote:

IANASE*, but gut feeling is that if you use some sort of half-truss arrangement for the roof (which will also anchor the tops of the walls and stop them from bowing) you should be OK. A diagonal brace across the side wall wouldn't hurt either, just to help prevent flexing in high winds.
* I am not a structural engineer :)
cheers
Jules
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It'll work, just about. I woudnt go that small though! Why not get the wood free, get a garden cut leylandii and quarter it.
NT
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wrote:

Next size up is quite a bit thicker. 47 x 50, as I recall, though Focus didn't have a big selection in Spalding. Perhaps *too* substantial for a little lean-to, I'd have thought? Mind you, if I could find it, 47 x 50 wouldn't be that much more expensive. I just reckon I can make a darn sight better job DIY than the commercial aluminium lean-tos that can cost over 200 for a 4' x 2'. I reckon I can do it for 100 or less. Horti glass here is 3 per 457mm x 610mm sheet.
MM
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MM wrote:

This might do you?

http://www.greenhousewarehouse.com/products/gh-palr-42-lt-palram-4ft-x-2ft-lean-to-greenhouse.html
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On Sat, 20 Mar 2010 08:17:57 +0000, stuart noble

I've seen it. It's a horrid little thing. From the advertising blurb: "The Ridge Height is 5'4" and the Door is 3'9" high."
Okay for midgets, I suppose!
At least the Eden Clearline lean-to (an alternative product) has a decent ridge height, but it's another 70 quid, and then they want another 30 quid for the "base" - just a rectangle of sheet steel: 30 ka-ching!
MM
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At 2 feet deep I don't imagine you'd be getting inside it :-)
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On Sat, 20 Mar 2010 19:53:24 +0000, stuart noble

I'm a short-arse. But not ~that~ short!
MM
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MM wrote:

why not just buy rough sawn pressure treated from a timber merchant?
?
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On Sat, 20 Mar 2010 08:45:27 +0000, The Natural Philosopher

They don't compete on price with B and Q, let alone Focus, where I, as a senior citizen now get 15% discount until 18th April. I've since worked out that I'll need about 16.2m of 38 x 38. I'm quite used to dowelling offcuts together end to end to minimise wastage. That'll cost me around 17 from Focus with the 15% discount (buying in packs of 4). Haven't yet worked out the total glass area, but let's say a ballpark of 10 panels (457 x 610) at 3 each = 30. Well, my lean-to is already looking vastly cheaper than the spindly, low-ridged alu-framed things on the web. The only thing they have going for them is the polycarbonate, but all I have to hope for is no hail.
MM
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MM wrote:

Try asking for discount then.
And also, ask yourself why not.
Could it be that their wood is actually suitable for construction, after all?
I've since

Holy crap Ebenezer, if a jobs worth doing, its worth doing well, surely? Not dowelled together bits of B&Q leylandii offcuts..
Oh and hail isn't the killer, its stones thrown up by the ride on and flying bits of hedge from the farmers flail.
Or next doors airgun toting teenager..
However my experience is that its still cheaper than polycarb, even if it needs a couple of new panes very year.

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On Sat, 20 Mar 2010 11:25:05 +0000, The Natural Philosopher

Okay, I finally rejected the treated timber, because when I went down to Andrews in Spalding all the treated stuff was outside and soaking wet. I didn't relish the thought of working with wet wood. So I compared prices and their kiln dry sawn timber was only a little bit more expensive, so I'm using that. Size 47 x 50 approx.
For cheapish glass replacement I've found a product called SAN safety glazing at 4.20 a sheet (457 x 610), but I've yet to receive feedback from the company (I always ask a question of a new supplier in order to gauge whether they are a good risk or not).
However, If I used horti glass, what do you think of the idea of covering each pane both sides with thin transparent plastic? I have spray mount adhesive that I use in other work and I was thinking of the cheap plastic sheeting off the roll at the garden centre (cheap as chips), then cutting two pieces, sticking them to the pane with the spray mount, then 'clamping' the 'sandwich' into the wooden frame with lipping bezels. Or is this all a bit OTT? The concerns would be: the plastic could detach itself from the glass over time and start flapping in the wind, making making irritating noise. Or the plastic would discolour over time (how long, though?). The big advantage is the safety of having any broken pane contained within the plastic sheets.
The GH is coming along really nicely, by the way. Should be finished in a few days. And vastly cheaper than anything you can buy.
MM
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MM wrote:

So?
treated will last 15 years in wet soil, untreated about 2.
I didn't relish the thought of working with wet wood. So I

Broken panes are a fact of life with horti glass.
I wouldn't bother with anything frankly.
You will want to scrub it occasionally to remove dust dirt and lichen, anyway. Pressure washer good.

I had an old Al frame, and some of its glass. The glass didn't survive being stored, and nore did half th new glass carefully transported home. there was a bolt head under the boot carpet that cracked the lower sheets from the weight of the upper.
All in all the glass cost nearly as much as a new greenhouse would have.
Frames are cheap. Glass is not.

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On Mon, 22 Mar 2010 09:35:23 +0000, The Natural Philosopher

I've since found acrylic 'glass' sheets 3mm thick for 4.95 (457 x 610) on the web, which I'm probably going to go for. Adds another 30 quid to the project, though -:(
MM
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On Mon, 22 Mar 2010 09:35:23 +0000, The Natural Philosopher

Ah, I was advised two hours ago by my local glass supplier that this occurred because you transported the sheets flat (I didn't mention your name!). He said one should NEVER transport or store them flat, but on the edge. He offered to deliver my order (horti glass) for free on his way home, so I'm back to using glass now!
MM
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Even horticulatural glass should outlast acrylic. The plastic gets scratched, dull & cloudy over time, ends up an eyesore.
NT
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It soon dries out.
NT
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If the pennies are really that tight....
http://www.youtube.com/watch?v=CB4uH8NoiPY&feature=related

NT
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wrote:

God, what an ugly monstrosity!
MM
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MM wrote:

Does Andrews in Little London still operate as a proper woodyard, or is it just a low-brow DIY hut now?
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