Greenhouse design.

Hi all,

I am finalising the design for the growhouse/greenhouse I am going to build over the autumn/winter. I am going to put a self opening window in the roof, but would I also need to put them on the side? It is going be 5x5 made out of 2x2 timber and 4mm twin wall polycarbonate with a sloping roof to the rear with a 2 inch drop.

Rusty

 

Hi Rusty , I`ve built one myself , before join the forum and made few mistake that I`m try to fix.
I`ve used only 6 mm clear acrylic and a flat roof , as a strange as it sound I was reading that in case of snow and really low temperature , the snow will keep the greenhouse temperature at zero celcious , and it would be easy to insulate with bubble wrap , not sure about it.
another big mistake is that didn`t put any window as i got sliding door and though that in hot weather i will simple open the door and job done , I do and cat are just go in and sleep on the plants or having kitten in there .
And finally you need a cover on the roof as in really hot sunny day the sunshine will burn the plants.
I`ve put bamboo on the top to stop direct light.

this is before

and because the humidity get really high , the plants just overgrowing

lot of shelves for the pot.

 

Hi Sal,

I am definitely putting at least 1 self opening window in the roof, but I was thinking of something on the sides, more to let air flow through like a slatted widow on conventional greenhouses, but im not sure a) if it is needed and b) how to put it in. Or do I just put another 2 windows on the side with self opener. I will have to have a look around and try and come up with an idea. The rest of the plans are sorted its just the side window/vent that I need to incorporate if needed. With regards the snow on the roof everything ive read says to get snow off as a build up is very heavy and can go through the roof. Using bubble wrap would be easy to fit using a staple gun and staple it to the wooden frame this is what I would do.

Rusty

 

what I understood last year is that you need a sort of heating in there otherwise temperature will still go down to -3/4 , another important thing is the location , mine is closed to the house so kept warmer by it and overall it`s all depend what are you growing , if your plants only need frost free then no problem if you try tropical then forget , you need to keep it at least belove 0 .
I`ve built mine with 5x2" roof , I usually walk on it with no problem , last year I had 5 inches snow on the top and it really seams to work as inside was quite warmer.

 

Sorry Sall, don't take offence, but.......................

 

OMG that just about made me wet myself laffing!!!! Toooooo funny!!!!

 

Good old GC!! Always able to raise a laugh - even on a roof, on a Sunday.

 

Rusty, good for you building your own greenhouse.
Regarding a roof vent, I think you might find it difficult weathering it if you only have a shallow 2in roof pitch.
I'd go for side vents and at least two.

Agree twin wall is a good idea, make sure its uv stable.

I'm not thinking you will require much shading with twin wall, as it tends to scatter the direct light anyway.

 

Hi Sal,

I have no intention of walking (or doing anything else on the roof) that is one reason for using 2x2 and I can get 3m of 2x2 treated timber to structural grade for £2.50 an length which is cheap. I will run it down a bench saw and slide the poly carbonate in which is 4 foot and then put a brace bar across which has also been down the saw then drop a 2 foot piece of poly carbonate on top with a brace bar on top. All the back panels and side panels and door will be made this way then screwed together. The roof will be made the same way by sliding the polycarbonate in but until the frame is done im not entirely sure of the size. This will be mounted on 2 angled pieces of treated timber like a coldframe would be with the 2 inch drop from front to back.

Rusty.

 

sorry all .............I mean walk and not the other .............omg , can`t belive it I just misspelled that word ......
One of the reasons why I joined the forum is to improve my writted English ....doing well am I

 

It was BRILLIANT Sal, absolutely BRILLIANT!!

 

Hi pete,

When you say 'weather the window' do you mean seal it to the elements?

Rusty

 

Not to worry Sal, it's happened to all of us at sometime and it gave us a laugh! It's got to be 'phrase of the week' though.

 

Yes, regarding rain, the greater the roof slope the easier it becomes

 

For who doesn`t know me I`m Italian and English is my second language , I verbally done even worst then that , I try not to use the computer speller and usually got Zigs correcting me..........one of is last email was .......
Hi Sal , in England we cook it and not cock it
Sorry all again.