Topic: What to replace glass with?

[Karen Atkinson]

I inherited an old wooden greenhouse. Over the last 2 years, the weather has taken its toll and the would has swollen and shrunk and as a result, a number if panes have been lost. The window frames are now of course, not regular size and I can't imagine them accommodating standard cut glass.

So what do I do? It's not yet falling down but  might if I removed the thriving but very old grapevine which I suspect gives it a certain stability. Also, I can't afford to replace with a brand new one. Can I replace the panes with something to be going kn with?

[alexmac]

Hi Spudcounter
Polycarbonate Sheet , not the corrugated stuff plain sheets. You can cut It to any shape. Drill and put small screws then mastic

[Karen Atkinson]

Great. Any idea where I buy it from?

[Vinlander]

Hi Spudcounter
Polycarbonate Sheet , not the corrugated stuff plain sheets. You can cut It to any shape. Drill and put small screws then mastic

I'd be interested to know of any advantage from using clear solid PC rather than the 4mm twinwall version (not corrugated - that's PVC and really is rubbish).

Twinwall is lighter, much, much cheaper and gives better insulation.

The only advantage clear solid PC has is that you can see your plants from the outside (and a few percent more light gets through) and looks better - at least initially (PC is so soft that it will look pretty scruffy after 1 season - it's also much harder to clean than glass).

The best solution is glass to the south and PC twinwall to the north. Glass lets in more UV for toms, peppers etc.

So if appearance-plus-toughness is the key then use solid PC for the side you see from the garden and twinwall for the rest - but don't try keeping desert cacti in there - they sulk from lack of UV.

I'm perennially irritated that clear solid PC isn't available in 1mm - because it would be plenty strong enough and I want to curve it for rigidity and use it as a clear cover on a fan peach - so I can see the blossom while keeping the rain and leaf-curl off during the critical spring period.

Acrylic and PVC are a waste of money as they become brittle in a few years. 

Cheers.

[Chrispy]

The best solution is glass to the south and PC twinwall to the north. Glass lets in more UV for toms, peppers etc.

I was thinking the opposite, twinwall diffuses the the light more, so help prevent plants getting scorched.
Had not thought about UV, do toms and peppers need UV?

[Vinlander]

The best solution is glass to the south and PC twinwall to the north. Glass lets in more UV for toms, peppers etc.

I was thinking the opposite, twinwall diffuses the the light more, so help prevent plants getting scorched.
Had not thought about UV, do toms and peppers need UV?

Well my desert cacti certainly sulk if they are kept under PC in summer and the climbing jungle cacti do too - a) they evolved to climb out through the canopy b) the canopy disappears in the dry season.

Toms & peppers certainly grow better in places that have more UV - so it isn't a problem for them - quite hard to prove they really need it rather than just stronger yellow light - but I'm always surprised how well they do outside, though it's hardly scientific.  I'm sure a need for UV could be bred out pretty quickly if necessary. UV - free conditions are supposed to repel bugs - if so then PC certainly isn't screening enough... they only need enough to see with.

I've heard that some plant chemicals need UV to be produced (was it capsaicin?) - but whether they are necessary for flavour or growth I couldn't say.

Have to admit I'm running on gut instinct and half-remembered advice on this one...

Cheers.

PS. I've only ever had scorching on plants that were actually touching the glass - AND they were understorey plants at that (Asimina triloba). But I do run a capillary system so nothing ever dries out, and my ventilation is automatic.