Self Build Greenhouse

dfbemt wrote: »

Right, that's it. After years of pondering I am now of the right frame of mind to self build a small greenhouse, approx 3 to 4m x 2m. Anybody any suggestions or help ?

The finished 'idea' was for a small / low wall and front off with a nice rustic brick. Then a timber frame structure and 'glaze' with at least twin wall polycarbonate. Plan to collect the roof water into an adjacent raised IBC and bring back into the greenhouse through a soaker hose.

Current area is currently under some rhubarb, raspberry and blackberry plants.

How does this sound and is there anything that I need to consider ?

Some questions so far
- any extra attention needed to ground / clearing the existing plants ?
- depth of foundation for the small wall ?
- do I need a damp proof course ?
- rustic brick or slips ?
- treated timber frame or finish painted ?

Will probably post some pics as I progress this over the Spring.......

looksee wrote: »

I don't know much about building greenhouses, but I do know that the fruit you mention will absolutely not be happy in a greenhouse, so clear the ground before you start - it will make it easier anyway.

Good point about moving the rhubarb and fruit as the wet winter weather is the best time to do this. I have raspberry that have spread into a poly-tunnel after being planted next to it and the fruit in the tunnel is consistently better quality and in greater quantity than the fruit from the outdoor plants. The problem is that if you have raspberry in the greenhouse they might leave very little space for growing anything else.


From my experience with the raspberry I reckon it would be important to get them all out of the area where the greenhouse is to be built so they don't get too vigorous and take over after it is built.


As to foundation depth for the wall there are engineering rules depending on the height of the wall and the thickness of the wall that should let you calculate what is required but I think you will need to calculate for the weight of the structure above that as well. A quick internet search would suggest between 150mm and 300mm for a wall up to 1metre but that is not counting the weight or stresses on the foundation from the rest of the structure. The foundation would also need to be a multiple of the wall thickness in width and I think an approximation would be about three times the thickness of the wall. If it was me I'd put some grid iron through the concrete and put in a bit extra on the dimensions to insure it will be stable in the long term. If you are ordering premixed concrete it should be easy to get a bit extra delivered whatever the dimensions you decide to go with.


Damp proof course sounds like something well worth including.


I'd choose to use normal bricks instead of slips just because I think I might be able to get the bricks to be more secure and likely to last the wear and tear they might get from the Irish climate, and other factors.


I'd go for a painted finish to the wood. I prefer the weathered wood appearance but a good thick gloss paint finish probably should make the timber last longer and also might deter wasps from chewing at it. I have a garden seat I was going to leave just as treated timber finish but it is getting attacked by wasps that use the material for building their nests and the girlfriend is allergic to their sting which makes using the seat on a summer day a bit of a risk with the amount of wasps that congregate there. Going to paint the seat when we get some dry weather.

rolion wrote: »

Guys...are we doing maths and engineering formulas for a plants and veggies greenhouse or a proper luxury living fcukign conservatory disguised as a greenhouse !??

The opening poster mentions having spent years pondering a structure with a low wall fronted with rustic brick supporting the glazing so I'm guessing a bit of maths and engineering to make it all more likely to stay standing for a bit longer might be a good idea. You could say it sounds like a conservatory disguised as a greenhouse but I think to make a good solid structure that is comfortable to spend time in for growing plants is a great idea.


Got a cheap kit greenhouse off ebay years ago and it barely lasted a couple of seasons with a light sliding front door easily blown off in the first major storm it faced even with it being in a fairly sheltered position. Refitting the poorly designed door was difficult and it easily came off again and then with the door gone and no exit point for wind at the other side of the flimsy structure it completely came apart soon after. I still have not found a good way of reusing the materials that were wasted in its construction. In a time when so much talk is about avoiding single use materials that can not be recycled making something that will last is the most environmentally sound way to go in my opinion and in the long term also probably the cheapest option.

Prince Tinkling Vase wrote: »

I was looking at a video last night of a guy making a wooden frame greenhouse with perspex roof and walls.

Would be ideal for where I am. Next year's project.

any link tp that

Have been reading this thread and the other one linked above. I'm thinking of putting together a greenhouse in the spring and an trying to weigh up my options. I'm not limited by space as we live rurally. I have a smallish veg patch, 2 hugelkulturs, a small orchard and a few hundred trees put in over the last two years. We got a nice lash of veg last year and are thinking of trying to grow more this year if we can. The site is semi-exposed but I have planted lots of windbreaks and trees so that should ease the wind soon I hope. I'm trying to decide between putting up a polytunnel and building a greenhouse with a few courses of blocks topped by a wooden frame housing double glazed pvc windows
I have around 10 good sized windows that came out of my father in law's house. I'm handy enough at making things and wouldn't be daunted by the task as such but trying to get the balance right between aesthetics, cost and longevity. I've looked at a few polytunnels and they come in around 1k roughly for a decent one. Pros are they're quick to put up, good ones will last a while as far as I can tell. Cons are my OH isn't that enamoured by the aesthetic as it will be in a prominent spot at the bottom of the garden (as I want to be able to run power to it), the cover will need replacing every few years.
To be honest, I'm not sure the blocks and windows one is going to look amazing either but will probably be more solid, will he easier to harvest water and run electrical bits.
Has anyone made this decision before and if so, what prompted you to go with one or the other? I really like the look of the one above with the upcycled conservatory but OH would prefer to use the windows as we already have them and could spend the money on blocks, roof etc instead.
Any opinions/advice appreciated. I'll definitely share pics and plans once I get going.