Greenhouse Foundation Question

[Dorsetman]

Surely it is the opposite ? To prevent damp travelling up ? Even ‘rot resistant’ will suffer if it stands on wet ground.

[Becca]

Mike, if it would prevent damp from traveling up, wouldn't it also prevent the water used for watering the orchids to drain through it? Where would all the water go?

---------- Post Merged at 01:53 PM ----------

Good thinking Geoff. I was thinking that we were discussing the entire floor, not just the foundation barrier.

Having said that, I had treated lumber benches sitting directly on a gravel floor in my greenhouse for over 25 years, and the damage to the legs was more by the sharp edges of the gravel than anything. Most "ground contact" lumber sold in the US is guaranteed for 40 years.

Becca - one more suggestion: See if you can make the foundation taller. Every increase in height increases the interior volume without appreciably affecting the critical surface area (solid wood won't transfer heat anywhere nearly as well as the greenhouse cover), making it a lot easier to stabilize the conditions within the structure.

Hi Ray! Yes I plan on raising the greenhouse by 18", it's not much, but better than nothing! Also I decided to go with a 240v electric heater, I was told that if the minimum temp of the greenhouse in the winter would be around 60 that it shouldn't increase my electric bill by more that $30.00 or so.