We are trying to finalize the design our planned new house, and it will have a full basement along with an attached greenhouse on the upper floor of about 600 square feet.
I have been going back and forth trying to decide if the greenhouse floor can reliably be made waterproof so that we can plan real living space below it (my future library?), or should I give up on that idea and fill it in, as in slab on grade.
What do you think and/or recommend?
Thanks
Getting the details right for a wall assembly with the control layers to the exterior and lots of drying potential.
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Replies
By "upper floor" I assume you mean the ground floor over the basement space, which you're considering finishing.
If it's truly a greenhouse (for growing plants) and not just a sunspace, then it requires good drainage in the floor - either one or more drains to daylight, or an earth-coupled floor that drains into the ground.
Living space under a greenhouse is a bad idea.
Well, really, a greenhouse ought to be the last thing you want "connected" to most "conditioned" buildings. The humidity is never right, the temperature also--so you actually want a middling-complicated "air lock" between the two.
Now, in all fairness, that depends on just what sort of "greenhouse" is contemplated, too. A "garden room" is a different space than a purist greenhouse.
Since this is upstairs, I'm guessing that pallets of mulch or compost are not likely to be handtrucked in. So, it will be more of a graden room than production greenhouse. In that case, a properly installed tile floor ought to be enough "waterproof" to suit.
Now, adequate insulation? You need a qualified person in Oregon to assess that, like as not. My "reflex" would be to thermally seperate the spaces as much as possible--but, it might be that the heat gain/loss might be benficial, just there on the edge of the Maritime climate you have.
Schluter ditra membrane under a non slip tile should work after all they use this material over sheet rock in showers. Sounds like a great idea to me.
ditra membrane under a non slip tile should work after all they use this material over sheet rock in showers. Sounds like a great idea to me.
That's what I was thinking, if this does not have a flood irrigation system or the like.
Otherwise it'd be a whopping big shower pan . . . <g>
But, a shower pan would work. Detailing would not be super complicated, and would probably pass plan review without too much trouble (past ResCheck review--that'd still be up for grabs).Occupational hazard of my occupation not being around (sorry Bubba)
Technically it should not be too hard to do. I have my shop under my garage.
But the specific reason is that because of terain I would have almost had to go that deep for the footings anyway and the have fill, fill, and more fill.
But if this a realatively flat area I don't think that the expense would be worth it.
If you are thinking about using ICF's of the foundation there are ICF decking systems that would give you nice insulated ceiling in under the greenhouse.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
We live directly under where we grow veggies. Never a leak. No greenhouse up there, but a glazed structure would make it one.
Capn's got some good points about temp/humidity, but if you control that, there shouldn't be any problem. Your library will have easy temp control with your plan.
Cheap space, get on with it.
PAHS Designer/Builder- Bury it!
My 27-year old house has a second-floor greenhouse directly over the dining room. Since my home is heated with wood, the temperature of a second-floor greenhouse is much easier to regulate than a ground-floor greenhouse; in a wood-heated house, ground-floor greenhouses get too cold at night.
I use my greenhouse from March 1 to June 15, to grow vegetable seedlings. The floor of the greenhouse is made up of sloped plywood, with two sides meeting in a "valley" down the center of the greenhouse, with the valley leading to a floor drain. I installed cheap sheet vinyl flooring over the plywood 27 years ago, and it hasn't ever leaked, in spite of the fact that I water everything with a spray hose.
I started my career as a roofer, and I thought like a roofer when I designed the greenhouse. There is a center aisle with growing benches on each side. The growing benches are covered with roll roofing, with cedar pallets above. My flats sit on the pallets. Everthing is sloped to the floor, everything is water tight, and everything is flashed like a roof.
Edited 1/23/2008 1:57 pm ET by MartinHolladay
Shouldn't be a problem.
Water proofing will be needed (something along the lines of showerpan etc. as other have mentioned).
Humidistat controlled ventilation, temp controlled ventilation to handle those issues and detail the green house side of the walls adjacent to the dwelling as if they were exterior walls.
Several of you have mentioned things that I was considering too, which is actually what I wanted to hear. I was worried that it was just plain crazy to consider this approach.
Yes, the foundation and upper floor walls of the house will be ICF, except for the greenhouse and due to the slope, as Billhartmann mentioned, I too would have 9' deep footings and tall walls under the greenhouse and then have to fill the entire thing with soil for the greenhouse floor. This fill, fill, fill, is what got me thinking why not turn it into my library.
The Schluter ditra membrane under a non slip tile route is what I was thinking too with radiant in-floor heat.
This will be a real greenhouse as compared to a sun room, but I am not that concerned about the temperature and humidity differences between the greenhouse and the main house since there will be a door between the two that is normally closed except during the time you actually go in and out. Possibly I should be more concerned with this?
However, there are many small but important details still pending such as, how to properly do the wall between the house and the greenhouse in floor to ceiling glass, and how to transition from the house roof to the glass greenhouse roof, etc.
Thanks for the input
Put a drain in the floor, it will make things much nicer.