[Goldfinger]

I'm not that good at maths so I'm a bit stuck ATM, Could some of you's help....

I've decided to totally re-glaze my greenhouse with polycarb, and not glass.

But, I want to know how many sheets of which size to get where I will have less wastage and cuts to do?

All help and answers will be grateful.........

GF

[mumofstig]

without knowing the size of your greenhouse, height to ridge etc etc we stand no chance


Gi's a clue   

[Goldfinger]

Whoops, Forgot to tell that bit,

It's a Crittal 8x6. Was on the plot when I took it over.

So, will all 8x6's similar in square ft or metre??

Help!!   

[ex-cavator]

Not that easy, I'm afraid. At the very least we'll also need to know the hight (to the eaves), and either the slope of the roof (in degrees) or the width (not length - we know that's around 8ft) of each half of the roof (assuming it's a ridge design). Then we can work out the total area of poly needed (including the 'pointy bit' at the top of each end).

But - that's assuming no wastage - it's highly unlikely all the individual panes can be cut from an exact number of sheets with nothing left over. For a start, what size are the sheets?

To answer your question with any ceretainty, we'd really need to know the measurements of each individual pane, and how many of each size. And what size are the sheets 

[Goldfinger]

Are most 8x6 greenhouses not nearly the same in measurements??  :blink:

Looking on the net, I've found Wickes to be the cheapest for sheets of polycarb, (twin walled 2.4m x 700mm x 10mm) £22.46 each or buy 5 at £19.09 each.

I was hoping someone might have already poly'd their GH and now know how many sheets are needed. 

[ex-cavator]

Assuming the eaves are 6ft high and the slope of the roof is 30 degrees:

Sides 2 @ 8ft long x 6ft high = 96 sq.ft
F + B 2 @ 6ft wide x 6ft high = 72 sq.ft
Plus gable ends:
2 @ 3ft (half the width) x 1.73ft (hight) = 10.4 sq.ft
Roof sections 2 @ 8ft long x 3.46ft (width) = 55.4 sq.ft

Total 233.8 sq.ft converted to metric = 21.72 sq.m

So, if sheets are 2.4 x 0.7 = 1.68 sq.m each, the ABSOLUTE MINIMUM you'll need assuming no waste whatsoever will be 21.72 / 1.68 = 13 sheets.

But allowing for the fact that neither the length nor the breadth of the sheet will be exactly divisible by an exact number of panes & therefore there will inevitably be quite a bit of wastage, you'll probably need about 16 to 18 sheets or so.

Sounds expensive 

[savbo]

Greenhouse Warehouse do 4mm twinwall in 610mm width (so no trimming sides) and in two length sizes (that are common dimensions for sides and roofs), in packs of 10....

you can overlap polycarb to fill gaps as I've just done on my ghouse.

I'm sure you've seen elsewhere you've got to glue them in with silicone or install bars to stop the panels popping out in the wind - clips will NOT hold them

a tip I've come up with - mark the insides of the polycarb once installed so if they DO pop out you know which is the UV stabilised side...

[Goldfinger]

Greenhouse warehouse....??

I'm off to have a look, Cheers  

Edit, just looked, can't find the 610mm width stuff in the drop down menu??  :blink:

[savbo]

Greenhouse warehouse....??

I'm off to have a look, Cheers  

Edit, just looked, can't find the 610mm width stuff in the drop down menu??  :blink:

it's not as easy as it should be but go to here
http://www.greenhousewarehouse.com/products/greenhouse-glazing/gl-tw-4-1220x610master-1220-x-610-x-4mm-twinwall-polycarbonate.html
and under Qunatity click the 'select' button and the multipacks are there

[Goldfinger]

Thanks for that link     

Am off to the plot  at the weekend to measure up properly to see how much I'll need

Cheers,

Chris

[gillie]

We did the end wall of a largish greenhouse many years ago after a big storm broke loads of the glass.  

Presumably you are going to replace the panes of glass with panels of polycarbonate with no overlaps.  You have to seal the cut ends of the polycarb with special tape to prevent water getting between the layers and to stop assorted small beasties making their homes in there.  We fixed ours in using the conventional W clips and no sealant.  They are still in place.

Make sure that you put the panels in the correct way round with the UV stabilised side to the outside.