View Full Version : Greenhouse leveling question
blownz281
09-09-2012, 01:23 PM
In the next few weeks we are getting a 6ft*8ft GH from Habor Freight. We have sandy soil here so I was wondering if I would have to worry about the greenhouse sinking at all? I'm going to place it on 4*4's and bolt it down. Should I rough the area/grass up where its going and lay down gravel? I can't cement anything down as this is a rent to own house. So if for some reason we didn't stay here the landlord would not be thrilled it being cemented down in the yard.
My parents have a expensive one and larger sized one. My Dad put the 4 wooden posts in the ground and cemented them in. Then made a foundation with 4*4's on top of that then laid gravel.
All the rain we have been getting this year the area we plan to put it has not sunk at all,but it has no weigh on it as well. Also no water sits in this area with all the rainy weather we have had. Thanks
sunfish
09-09-2012, 03:57 PM
You can lay down some brick or pavers in each corner leave about 2" above grade and place 4x4's on top.Keeps the wood out of the dirt. Go get 4 concrete form stakes, the metal ones , drive them in the ground and screw into 4x4's .
You can lay down some brick or pavers in each corner leave about 2" above grade and place 4x4's on top.Keeps the wood out of the dirt. Go get 4 concrete form stakes, the metal ones , drive them in the ground and screw into 4x4's .
Yep, be sure to pin the critter down to the ground securely; maybe even use some screw-in anchors if the soil is otherwise on the spongy side when soaked.
It gets real embarrassing (not to mention messy) when somebody's greenhouse or shed winds up "switching yards".
:bananas_b
blownz281
09-09-2012, 05:08 PM
Yeah guys I will have to anchor it down one way or another :)
Olafhenny
09-09-2012, 06:39 PM
How you do it, depends partly on how long that installation is supposed to last. If you are leaving
home within the next ten years, you might get away with just driving 4 or 6 2x4s in to the ground
18 inches deep and screw or nail your bottom frame to those posts. Of course all lumber you
use for this purpose should be pressure treated.
Placing your lumber on pavers is not a good idea, unless they are clay bricks. Most pavers
today are concrete and concrete in direct contact is poisonous for wood, because it attracts
moisture and maintains it even while everything around it is dry.
If you have a car port or one of your neighbours has one, look at the bases of the posts. You will
see, that they are not set directly into the concrete, but nailed/screwed into galvanized steel
brackets, which are in turn set into the concrete.
Here is how you build a ‘Cadillac’ base, which will cost you only between 20 and 30 bucks more
than the ‘slip shot’ solution, which I have described above:
- Dig a hole in each corner 1 foot deep. It need not be more than 8 inches in diameter, but
should, if anything, flare out at the bottom.
- Fill these holes up with concrete and insert a bracket into each concrete filled hole. This
is, where the whole quality of the job is decided. The brackets should not only be square to the
frame, touching with bottom of their base plates the concrete, but also all be exactly the same
height. For that it is helpful to pound a hub (small stake) near each corner, after you have dug the
holes marked for elevation, from which you can easily measure down to establish the top of the
concrete. But before you pour the concrete, you should make sure, that there is no loose soil in
the holes. – Well, a little bit is unavoidable, but basically the pour should be against undisturbed
native soil.
You can find illustrations of the brackets I am talking about here:
Concrete Fence Post Metal Anchor Sales, Buy Concrete Fence Post Metal Anchor Products from alibaba.com (http://www.alibaba.com/product-gs/553276436/concrete_fence_post_metal_anchor/showimage.html?s=p)
Chose the one on the bottom left, if you plan to bolt the 6’ cross on top of the 8’ stringer or one
of the two beside it, if you want your frame to be flush. In that case you may want to consider
using two 2 x fours bolted together instead of one 4 x 4. That would allow you to fashion an
overlap joint at the corners.
You can be sure to find these brackets at your local building supply store for about a couple of bucks
each. For concrete I would recommend bagged ready mix. One bag will probably not be quite
enough and with two, you will have some left over. :)
Good luck, I have tried to go into quite a bit of detail, but if I left something out, then feel free to
ask.
Olaf
blownz281
09-09-2012, 07:40 PM
Wow thanks,okay I will let you guys know what I end up doing.
Whichever way you go, you may want to look into "temporary" vs "permanent" definitions for your location; "permanent" installations can be taxable & become part of the property, not being able to be taken along if/when you should move.
"Temporary" installations may not be subject to property taxes & may be taken with you if you should move.
Just something to think about. ;)
:bananas_b
blownz281
09-09-2012, 08:16 PM
Yeah,the Landlords daughter leaves next door! If we do leave I don't care the greenhouse and all my plants are coming with us,with or without the deposit. Nothing we did can't be changed around. The yard looks a million times better!
cincinnana
09-10-2012, 09:54 PM
Yeah guys I will have to anchor it down one way or another :)
When I had mine I used 6x6's as the frame base and pinned it to the ground with 1 inch rebar..... pounded about 18 inches in ,three each side with about 6 inches above the wood. I used wood chips as the floor.
4x4's might twist and bend the thin aluminium frame.
Sounds like a good project.
Don't forget to use your coupon for 20% off.:08:
Good luck
blownz281
09-11-2012, 08:57 PM
I was thinking about the rebar myself. On youtube people said they used 4*4's. But no idea down the road how that worked,they were also in cold climates. I will use burlap or gravel for the floor. Wood chips will bring in cockroaches. Thanks,I'm looking forward to it,yes I have my coupon.
Abnshrek
09-11-2012, 10:20 PM
IS there anyone with old / used, but in good shape RR timbers to use for the base?
If so put a wanted ad on craigslist wouldn't hurt.. :^)
blownz281
09-12-2012, 05:41 PM
Yes that's a thought :)
pour a "foot" on your posts
drive a couple galvy nails half way into the bottom 8 inches of your posts
set post in 5gal bucket (plant containers work well too)
pour 1 bag concrete mix into each
if you grease the inside of the bucket and insert a trash bag then you can even reuse your form
the same can be done with any size or shape "Foot" you want to pour
when you want to move the concrete can be removed with a couple whacks from a hammer
Olafhenny
09-13-2012, 09:28 AM
when you want to move the concrete can be removed with a couple whacks from a hammer
You are kidding, aren't you? If I could do that, I would sue the concrete manufacturer.
I've removed 200ft of sidewalk with a 20lb sledge.
Removing concrete from a wood post is easy because the wood penetration causes a doughnut effect further weakening the concrete against shock.
The corners of the square post are thinnest and that is where you should aim.
Scuba_Dave
09-13-2012, 10:33 AM
I've also removed concrete from 4x4's with a sledge, it does tend to break off the post fairly easily
PT 4x4's will tend to twist/warp some, the 6x6's are much better
the 6x6's are much better
werd
6x6's FTW !! :goteam:
seriously though
I don't think anything is sinking, but wind is very unpredictable.
Anchor it somehow to prevent damage to property, and your greenhouse, and wallet.
Olafhenny
09-13-2012, 12:15 PM
Years ago there was some junk on the market called something like 'post hole concrete' or 'fence post
concrete'. But that is no longer sold here, probably because some people used it where they shouldn't
have and got into trouble.
If concrete was as fragile/soft as you guys describe it, all the concrete structures on this planet
would have collapsed, long before construction was even finished.
If 'Blown' has railroad ties or 6 x6es readily available, by all means use them, but as base of a light
weight aluminum structure it is overkill, if you have to buy them.
Scuba_Dave
09-13-2012, 01:28 PM
Concrete is not fragile, but a 10+ lb sledge hitting it on the side breaks it off without a problem
Its not a matter of being soft, it wasn't designed to stand up to being hit with a sledge hammer
The brittle and low tensile strength properties of unreinforced concrete cannot be denied.
Doubtless many concrete structures did collapse during construction before the nature of the material was fully understood.
They would continue today, and at a higher rate , were it not for the incorporation of steel and other polymers.
blownz281
09-13-2012, 03:48 PM
Thanks guys. Have a local guy on craigslist that has some 6*6 and I think he said RR ties. Hopefully they are good enough to use. I have a bunch of bricks laying around I want to put underneath them,to keep the wood off the ground.
Olaf - if you look at harbor Freight's website the 6ft-8ft greenhouse is what I am getting. I don't want the metal laying on the ground. Being coastal and hurricane season being August-September I would need some way to secure it and be able to remove it if I had too.
pmurphy
09-13-2012, 06:05 PM
I am not sure what material your greenhouse if made of but it is mostly likely polycarbonate panels, and I found that these greenhouses are not that heavy. Once set up they can easily be moved by one person (just clumsy) so you may not have to worry too much about settling; if anything, your 4x4's will probably weigh more.
I would simply dig a trench into the soil and lay your pressure treated 4x4 in this trench, making sure they are level at this time (once you get below the first couple of inches of soil is should firm up). You might even want to do a second level and bolt them together (I use 2 layers of landscape ties that were "overlapped" at the corners and then nailed together - usually cheaper than 4x4's and already treated). I then bolted the greenhouses onto the ties and placed a couple of layers of landscape fabric inside with rocks to help prevent weeds etc from growing.
I have found this worked for both of my greenhouses, one of which has been set up for almost 5 years now.
blownz281
09-13-2012, 06:08 PM
Thanks
pmurphy
09-14-2012, 09:15 AM
FYI, the reason I suggest digging a trench for your 4x4" is that the frame of your greenhouse will most likely create a "box" - meaning that if you attach it to the 4x4's it will raise the bottom of the door that same height and create a sill that you will have to step over. Not the biggest worry, you just have to remember to "step up" - which took me a couple of weeks and banged shins to remember with my first greenhouse (the second one sits at ground level). Your biggest issue will be if you are moving large or heavy things in or out, they will have to be lifted over the sill.
Pam
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