Greenhouse being reassembled: need advice re several problem

Hi everybody,

I bought an English greenhouse - Eden - in 1991 when I lived in central North Dakota. When we moved to my present home in western Minnesota in 1998, I disassembled it and brought it with me. It's been in the barn for 16 years! (Child-rearing and career, you know the drill.) And this fall I am finally putting it back together.

It never was very well sealed. The gaskets that sealed long edges of the panels were OK - but there were way too many places along the top and bottom ends of the panels without any sort of weatherstripping or sealant whatsoever. I remember well, trying to caulk all those places. What a mess. This was pre-internet, so I didn't have access to any Great Advice like I'm hoping for today.

So now, before I put the Lexan panels on, I'm thinking of getting some kind of weatherstripping that will stand up to greenhouse conditions. It could get wet, obviously. It will get very cold, in Minnesota, down to 30 below for a night or two, most winters. (Maybe a few degrees lower, but that's rare.) It will get very hot in summer, with high humidity.

What can I stuff in the cracks that will stand up to this, and resist mold/algae formation? *Should* I simply stuff something in - something that's not necessarily defined as "weatherstripping", or that's not necessarily adhesive? Or can I just run over to Menard's/Home Depot/Fleet Farm and get whatever looks like the right size? That foam stuff that comes in rolls with at least one side that's sticky?

While we're at it: with two-ply Lexan, how important is it to have ventilated tape on the bottom edges of the panels? I hear about preventing condensation. BUT. It's very, very dry around here right now. If I seal both top and bottom edges with the nifty Nashua waterproofing aluminum butyl-backed tape in this time of very low humidity, will I have really mucked up the job? (Seems to me that a number of bugs and a lot of dirt made short work of those ventilated bottom strips. Not good.)

(Re sealing up drafty panel ends: I'm wondering whether that Nashua waterproofing tape wouldn't do a darn good job. Hm. Maybe protect against moisture too, if it goes over foam weatherstripping?)

And finally: a number of the panels are pretty yellowed. Especially the ones that faced the sun during this greenhouse's first life. I'm going to reverse things, and put those on the shadier side. Do I need to be thinking about re-glazing the structure? How hard is it? Can I maybe use slightly thicker panels when I re-glaze, if I smoosh the clips down a little? ;)

Not much decent weather left here, although we've been amazingly blessed, so if you have any advice, gosh I hope to hear it soon! Thank you! Otherwise I'll just go do the best I can and learn from whatever my experience turns out to be.

And just because everybody likes pictures ( ;-D ) here's where I ended the day:

Hi joanlc, sorry to be posting so late (you've perhaps figured things out, by now.) I just had a few comments that might help.

I have a 10x12 Harbor Freight greenhouse that has been up about 8 years now. I used weatherstripping around all four sides of my panel openings. I suggest looking for closed cell weatherstripping, as opposed to open cell (it should say on the bag.) The (cheaper) open cell stuff can absorb water, like a sponge, in my experience. The closed cell stuff will stay impervious. In my hot climate, even the closed cell weatherstripping gives up the ghost eventually, but I think it's better to use the higher quality stripping.

When we put up our greenhouse, I was very careful to have perforations in the tape I used on the bottoms of each panel. I didn't buy special tape from a greenhouse supply co (cheapskate, here.) I used aluminum tape from Lowes. That started peeling off in about two years, due to our brutal sun/heat. I retaped the panels top and bottom with clear duct tape, cut in half widths. This time, I did not worry about perforations on the bottom panel, just sealed them both.

Honestly I can't tell any difference. I think in my dry climate, it really isn't crucial to have perforations on the bottom panel tape. In wetter climates, maybe it is. I don't worry about it anymore.

I hope you can keep making good progress, how nice to finally be using yours! I'm trying to finish up my fall plant load-in as we speak. I sure have enjoyed my greenhouse, and I'll bet you will too.

Thanks, "Muddy," for your words. I think I'll take that advice, and tape up both ends. Makes sense to me.

Meanwhile: I have the aluminum framework of this greenhouse entirely assembled, but there it sits, the bones of the greenhouse, awaiting glazing.

As I think about it, it seems like the right thing to do, to just slap the old stuff on there and not fuss about either taping the ends or doing any other proper insulation, in order to keep the ground within the greenhouse perimeter from being as icy as might otherwise be the case. And then if I get lucky and we have a mild late winter/early spring, re-glaze with new, fully-taped panels when possible (weather-wise, and panel by panel) before the greenhouse really needs to be in production mode. Worth dreaming about, at least.

Also, re closed-cell: Definitely! Anything open-cell is going to be a mildew/fungus magnet, right?! What sort of closed-cell do you use? Marine-grade? Is it reasonable just to buy closed-cell foam, like one might use for seating cushions for a sailboat, and cut it into strips, and stuff same into the gaps? It seems to me that this is likely to produce a both more effective and less messy, more replaceable solution, when necessary, than any sort of caulk. Do you see any downside?

Thanks again! You've helped me clarify my thinking.

I'll get out there and start slapping that glazing on at any opportunity, over the next week or so. And we'll just see what happens, come 2015.

J

Oops, sorry for not finding your reply sooner, joanlc. I had a hectic week and lost track.

I calculated how many feet I needed for my own greenhouse (I wanted to use it around all four sides of each of my panels, as I installed them.) Then I priced closed cell foam weatherstripping at the local box stores, like you use for windows or doors; it comes coiled in plastic bags, with one sticky side, and a paper strip you peel off. It was fairly expensive (only because I needed so many bags of it!)

Then I found a surplus seller on eBay who had large quantities of weatherstripping for a much lower price, but their stripping was too wide. So I bought many packages of it, and simply cut the width in half with scissors, as I went along. Worked out great, and was a lot cheaper than buying it at Lowes.

I needed the weatherstripping to be adhesive, for my greenhouse, which was not really designed for weatherstripping; I outlined each panel opening with it, then placed the panel on top. That gave me a nice seal around all the panels, when they were clipped into place using the metal springy glazing clips that Harbor Freight uses.

On the Harbor Freight greenhouses, some people do use caulk to help secure the panels. Personally I like to have the freedom to remove mine, for cleaning, or easy access to move big pots in and out of the sides of my greenhouse. Or, to make changes like adding exhaust fans, etc. I don't know how the Lexan panels are attached to an Eden Greenhouse, so it's hard for me to advise you about using caulk, or not. I'd just agree with your comment that using something else will be easier to remove or replace. I guess it depends how "permanently" you want all of your panels attached.

And, since I'm not familiar with Eden greenhouses, I'm not sure how or where you will attach the weatherstripping, but I'm sure you'll be able to make a good judgement, and find something that works. I think the stuff you buy at the box stores (or elsewhere, as I did) would work fine, as long as you avoid the really cheap stuff that looks like very porous, fragile lightweight spongy foam. The closed cell stuff looks and feels more dense; sometimes the bags refer to it as "weather proof" or "weather resistant."

In a few places, up by my roof ridge, I did have a deep gap that needed more of a "stuffing" weatherstripping than an adhesive one. (If you understand my silly terminology.) For those gaps, I used caulk backer rod (in the same department as the weatherstripping, at the box stores.) This stuff is gray foam that is perfectly round, like a flexible foam rope, in varying thicknesses. It's not sticky; just designed to be used as a filler for crevices. It's good if you have crevices or gaps that need something wedged in place tightly (as opposed to a flat surface where you need to adhere a strip.)

Hope this helps!

I have used polyester felt from the local fabric store, cut into thin strips, as a cheap alternative weather stripping to seal off the polycarbonate sheets of my GH. I also used poly felt when I had a freestanding glass pane greenhouse with aluminum frame. I use polyfil stuffing in nooks and crannies to get a better seal on the current corrugated roof because the styrofoam sealers are inadequate. Two of my wood framed GH walls (north and west), along with the roof, are attached to the house and two (south and east) come off completely. The reassembly of the later two walls requires annual re-installation and re-insulation that takes only a few hours.

I wholeheartedly agree with Mudhouse. the impervious tape will prevent the absorption of water which can freeze and heave the panels loose. I did the same as her as far as using aluminum tape on the ends of the panels, I did perforate the bottoms though because of our freeze cycles and humidity. Best of luck in your efforts.