Hi
@Squashboxer,
Looks like it was just designed that way...not for any special reason that I can think of, unless it adds to the wind resistance. I have seen similar. What I don't like about the sloping walls is you can't plant right up against the walls if you are growing anything of heaith, since it will hit the sloped panels.
Is there a frame under the hardboard? If it was me, I would probably elevate the greenhouse onto some 6 x 6 rot resistant frame...like pressure treated wood rated for ground contact or if you can find a local sawmill, you could see if they have some rot resistant wood like locust. I would also take out the linoleum, and if necessary, dig down 6-8 inches, put down a good quality weed barrier cloth and fill with gravel of your choice. (If you raise it up on a base, there will be minimal digging since you already have an additional 6".) This would help with drainage. If you don't like the gravel, you can always apply some slate or cement walking stones on top of the gravel.
If you raised it up onto a frame, make sure you anchor the frame into the ground. The easiest way to do this is to put 2-3' rebar pieces, 2 in each corner, driven at an angle (either inward toward the greenhouse or the opposite direction from the corners) into the ground. Then, anchor the greenhouse to the ground frame. Angle irons which you can buy in any big box store can be placed every few feet with screws. The greenhouse may seem heavy, but I have seen many greenhouses that have not been anchored blown all over the place.
Hope some of the above is helpful.
