[NettleBed]

I need to move my green house. Obviously I will need to construct a new base.

What are your preferences?

It's an aluminium gh about 10' x 6' maybe a little larger. I don't intend to grow anything directly in the ground so I'm thinking concrete base or concrete foundations and a gravel infill.

Are there any major advantages or disadvantages to either plan?

E.g. drainage, weeds, temperature stability, anything?

Thanks

[Kevin67]

I'm in the league of less is more.

So less work means more gardening - yay!

The only thing I would be interested in my greenhouse doing at the base level is keeping rodents out. So I'd be tempted to have a perimeter of bricks and/or treated wood and sit and secure the g/house on top of that.

So for the years I don't want to grow in the ground of the g/house I'd put some membrane down so that if/when I change my mind it's super easy.

Think of the money you'll save. 

[NettleBed]

Have to admit I'm veering to a gravel/scalpings interior.

Less concrete mixing and less chance of the gh flooding and if I change my mind as you say.

[Kristen]

Much prefer my greenhouse borders to when I used to grow Toms / Cues in pots.  I now water every other day, much easier to control than days-of-old and watering multiple times each day.

Mine have a 2-course brick base. Bricks are a bit soft and some have got frost damage, if doing it again I would use engineering bricks.

Only advice is to make sure the diagonals are exactly equal before re-erecting, to be sure it is square, otherwise you won't be able to fit the glass!

[sunshineband]

Whatever you decide (and I am in the "make it taller" camp with a step into the greenhouse) do make sure the base is completely level on absolutely solid ground, or you may find the frame of your greenhouse twists, with disastrous results

[Aidy]

Whatever you decide (and I am in the "make it taller" camp with a step into the greenhouse) do make sure the base is completely level on absolutely solid ground, or you may find the frame of your greenhouse twists, with disastrous results

2nd that, a 10x6 or bigger will have a fair amount of weight and is likely to sink at some unless footings were solid.

[Kristen]

do make sure the base is completely level

What you said, but I would favour a small fall towards whichever end the gutters will drain into a waterbutt (or just disgorge - which might be better at the back than the front )

[snowdrops]

Whatever you decide (and I am in the "make it taller" camp with a step into the greenhouse) do make sure the base is completely level on absolutely solid ground, or you may find the frame of your greenhouse twists, with disastrous results

2nd that, a 10x6 or bigger will have a fair amount of weight and is likely to sink at some unless footings were solid.

Hmm that's what happened to mine & was to be resited last year but didn't get done, but now we are moving will have a new garden to be put in & hopefully hubby will take the weight of a 10 x8 with toughened glass in to consideration next time, also it was supposed to have no step as I can fall over nothing. Height doesn't come in to it as I'm a short @ rse anyway. But it's a rhino greenhouse & was one of the tallest ones I looked at

[Growster...]

You should be OK laying the base - which I assume is an aluminium channel base if it's a Hall's model - on 4" concrete blocks, placed flat at intervals of a couple or three feet  and levelled. We have used this method twice, and the second time, we used 18" x 18" paving slabs laid on sharp sand all over the inside. It's worked well, and is free draining if any watering goes awry!

All the toms, cuces and peppers are planted in long planters or big high round pots, and stood in deep trays, so watering is dead easy!

If you are using glass then the whole structure will that much heavier, but also sturdier as well, and will be less likely to blow away!

[andimac]

Hello,

I'm about to get a greenhouse in May. An Alton 8 x 12 so it should be fairly heavy. I am about to start clearing and levelling the space for it which will be approximately 10 x 14ft.
What would you recommend for the base? I am tending towards using slabs with some hardcore then builders sand under the slabs as it would allow for border beds but I am a newbie to this...
All advice welcomed!

[Kristen]

I would put a concrete footing in.  Its a fair seized greenhouse and maybe? slabs might move independently of each other?

I found these on the Alton site:

http://www.altongreenhouses.co.uk/why-alton/installing-your-greenhouse
http://www.altongreenhouses.co.uk/pdfs/greenhouse_base.pdf

[Kristen]

Personally I much prefer borders in the greenhouse to a hard base and containers.  I've had both, over the years, and watering the borders is much easier - but the soil does need replacing periodically.

In my "cropping" greenhouse I lowered my borders (I have concrete footings and a couple of courses of bricks as the base to mine) in order to have more cropping-height to the roof).

I also have a staging-only greenhouse and that has a hard floor.

[Kristen]

Found some photos:



Staging greenhouse - I have mist propagation under the staging



Cropping greenhouse - lowered borders

[Lardman]

How long is it going to be there?

http://chat.allotment-garden.org/index.php?topic=111679.0 Here's what I did for my 8x10'. Strip footings, 4 course of engineering blocks. All built level(ish) then 2x1" wooden strips bolted to that with a slight fall for the gutting and the greenhouse then screwed to the wood.  The floor is weedproof membrane covered in chippings and I grow in pots.

[andimac]

Lardman, I am hoping it will be there at least as long as I am! My greenhouse comes with a concrete "kerb/base" to keep the wood away from damp ground so I shouldn't need a course of bricks. What I will try to do however is put in a slight gradient to the rear so I can allow rainwater flow. I'm not sure how to secure it to the concrete yet so I will need to check up on it.
I've just been reading your thread on building your concrete base. It has supplied me with lots of lovely ideas which I shall adapt (i.e. shamelessly nick!) for my project.

Kristen, those links to the Alton site are pretty useful so thank you for posting them.

I think what I will do is a mixture of the photos posted.
Obviously I will make sure the site is reasonably level (it isn't too bad just now but needs a general tidy up).

I'll then put in a concrete footing around the planned border ( like Lardman's wall foundation) and with sufficient external overlap to help keep weeds off. I've a lot of engineering bricks left over from a driveway at my old house so I could use them internally for a central path like you have Kristen. Even if I have to buy some more to, it'd be cheaper than installing concrete and it'll allow me to have internal borders for planting out tomatoes etc. I could even raise the internal bed slightly with one level of bricks.

More importantly, it'll save me from the ordeal of digging out the entire greenhouse footprint only to then fill the hole in with ballast and builder's sand.

Thank you both for the advice, suddenly it doesn't seem quite so daunting...

I will get photos sorted once I am back home.

I'm also about to move my 6' x 4' greenhouse from my old house and hopefully I can reclaim the slabs it currently sits on. 2 greenhouses, woohoo!!