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

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

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

Make sure its treated.

I plan to dunk the timber in creocote (creosote substitute) prior to assembly. It's what my dad used for building a number of poultry houses on our smallholding in 1957.

MM

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

This might do you?

why not just buy rough sawn pressure treated from a timber merchant?

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

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

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

Both apparently

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.

They have ~some~ timber, but the last time I was there it wasn't a great choice. And not especially cheap, either.

MM

I'd probably go with 3x3 for something that small. You can get pretreated 3x3 fence posts.

NT

If the pennies are really that tight....

At 2 feet deep I don't imagine you'd be getting inside it :-)

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

MM

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

Ah, that wonderful "shed" smell. Were the poultry on a "legal high" most of the time ? Simon.