You could caulk it on.

Be sure to trim all loose edges that the wind could catch.

I used tarp clips. I folded the cover over a small stick or toothpick and clamped the fold and the toothpick in the tarp clip. Pop the bubbles on the cover where the clips are. Then lots of bungie cords and rope.

In the end, it didn't work very well for me and I intend to reapply strips of the solar cover on the inside this year.

Dang,

I was hoping someone would have a good solution for this. The clips and bungee cord routine did not work well for me either last year and I'm in a spot that gets very little wind too.

I have puzzled over this most of the summer. I have a handy dandy little tool in my craft closet that will put grommets in and I was wondering if they would hold or just tear out and shred the ends of my cover.

Any one have any other suggestions?

Cindy

If you have baseboards on the sides you can either use a wirelock system or firring strips among other choices. For the firring strips screw two rows of strips on each side parrallel with the ground leaving room for a loose fitting third strip between them. Then after covering with your cover push the third strip over the cover sandwiching it tichtly between the outer two strips. three or four screws per 8 ft will hold that strip and your cover secure. You then can use batten strips on the ends so wind doesn't get under any surface.

You'll need to pop the bubbles to get a tight fit whereever you secure it. You should be able to remove it and reapply the cover without much additional work.

I got a roll of the pool cover for my 15x40 GH and I plan to permanately sandwich it between two poly layers and then inflate on both sides of it. I just hate to do it before the double poly layers that have been on for 12 years will need to be replaced. I am securing it with the firring strips but plan on switching to wirelock (longer life).

my problem was that I did not get the pool cover large enough !

However - I could lay a layer of poly over the top - and cover the pool cover. I would be able to extend the single layer of poly to the bottom of each side and attach with a the method you described.

Wow - lots of work

Still thinking

Do consider clear caulk. It's not too expensive, it's easy to apply, and it's good for sealing up joints (i.e., helping prevent the wind from getting under it, which is what will get it ripped off) in addition to holding things together. You could combine it with another method of holding the cover on.

Dam I just bought a Solar pool Cover this week.Last winter I was seeing posts about how great these covers were so I bought one for mine and now I read that they won't stay on.
Looks like I'm going to have to come up with a way to keep it on now that i have my money invested in one.
I bought a magni-Clear and it appears to be strong but the bubbles are small and it will not insulate as well as I had hoped for. I probably will put bubble insulation on the inside also. With the price of energy being what it is adding insulation is cheaper than paying to heat it.

My experience is with a much smaller structure, gwb, but it didn't budge through winter storms. I think the key, as a few have already mentioned, is to eliminate spots where the wind can get in there, catch hold and do its mischief. With the resourcefulness you've shown so far in modifying the greenhouse, I'm sure you'll come up with something.

Looking back at my log from last winter, comparing before and after spc, same time of day, same weather conditions, it looks like the spc increased the temp differential between outdoors and the greenhouse by about 10 degrees. That was before I discovered and blocked the drafts where foundation meets ground. Unfortunately, I don't have much data from before adding the spc.

I hope it all works out for you better than you're anticipating.

Di

The smoothness of the double poly is part of the probelm - It does not take much to move. If you have a rigid frame covered with a hard surface - I think that the cover can be then secured very tight.

If there wer ( like a tarp) small brass grommets - it would be much easier to secure. Also my pproblem is that it does not reach all the way to the bottom of each side of the GH. If it was long enough I could secure at the wooden base.
I am thinking about the caulk - but the worry is taking a chance the the poly skin could tear.

Keep coming with ideas. I spent too much on this to give up

Don't know how close to the foundation the edge of your cover comes, but just thinking here: How about folding the edge of the pool cover over and securing it to itself - creating a long channel through which you could then run some type of wood or metal rod. You could then lash that rod, either just the ends or along the entire length, to a second rod or U-clamps attached to the foundation. A strong enough wind from the right direction might get up under the cover somewhat, but I doubt it would go anywhere, (unless you had a hurricane or tornado, and then you've probably got bigger worries anyway) and the rod should help distribute the tension more evenly over the entire length, rather than having the full force on individual grommets.

I'll have to remind myself of some of these issues whenever I get jealous of you folks with the bigger greenhouses.

Di

Does caulk stick to polyethylene? Nothing else seems to.

Caulk can stick to PE and PVC; I just replaced the outer skin of my greenhouse, and as usual, caulked it on (my outer skin is PE, and the inner skin is PVC. The PVC absorbs the IR, and the cheap PE provides a replacable skin for extra insulation). My layers are separated by small squares of insulation to provide a nice air pocket -- also caulked on. On the other sides, I have aluminized insulation caulked on.

Don't just use any caulk; go to your local mega-hardware-store and ask what will bond to PE. It'll take a lot, of course. And, as has been mentioned, make sure that there are no loose ends to catch the wind.

http://www.stealth316.com/2-dp8005.htm

"Cyanoacrylate, epoxy, polyurethane, silicone (RTV for example), and most acrylic adhesives do not stick to polypropylene and polyethylene. I have personally verified this with cyanoacrylate ("Superglue"), two-part epoxy, and several types of silicone RTV adhesives."

In my limited experience with silicone and PE the glue will seem to hold for a while, then let go catastrophically. Better to use a mechanical join like the standard zigzag joiners used for tunnel greenhouses.

Funny, I've never had a problem before. Of course, I only had my last caulk on for about a year, so perhaps I just got lucky. :)

To back up, I think that your best bet, glue-wise, is "sticky", flexible adhesives like silicone-based caulk, if anything, to support an additional method of attaching it simply by stopping wind from getting underneath. It's more of a "tacky" bond than a weld, but it's held for me so far (thanks to copious amounts of it being used). For something of a more rigid, permanent bond, google reveals that there's things like 3m Scotch-Weld Structural Plastic Adhesive DP8010. Supposedly a bit hard to find and expensive, but then again, how much do you need?

I plan on bringing the Pool Cover down the sides and anchor it to the ground or foundation but at the gabble ends it will just come to the edge of the roof. This will allow the wind to try to lift it at that point. I have some long nylon ratchet straps that I could place at each end and pull them down tight. That would hold the ends down really tight. I don't want to use adhesive because in the warm weather I want to be able to remove it easy without having to clean up a mess from the chalking.

why do you want to remove it in summer?

Posted by nathanhurst VIC Aust (My Page) on Fri, Sep 29, 06 at 20:18

why do you want to remove it in summer

I plan on putting it on the outside and bubble insulation on the roof on the inside.
Will need to remove in warm weather for the roof vents to open. Magni-clear claims that it will increase water temp in a pool 10 to 15 degrees seems logical the it Will try to heat my GH also. I will replace the pool cover with a shade cloth

It seems to me that the only reasons for taking off the cover are 1) vents, 2) aesthetics, and 3) wind or wind damage. If the cover transmits 80% of the light, then it's a 20% shade cloth and that could even help with daytime summer cooling.

Another thing the cover does is diffuse light. Diffusion is something we haven't talked about much, but light diffusion prevents foliage burn, improves photosynthesis, and decreases internodal stretch and plant height.

I'm thinking of leaving the strips of my solar pool cover up in the summer too. Any good reasons not to?

Posted by stressbaby z6 MO (My Page) on Sat, Sep 30, 06 at 8:56
the cover transmits 80% of the light
stressbaby You have me confused if it only transfers 80 percent of the light how does it heat the pool.
Is it the bubbles insulate and hold the heat in.
That is the only explanation I can think of for it working like they say if it transfer less light.
I still think I will remove it and use a 50 percent shade cloth. Even without the pool cover I can heat it. Heating it isn't hard to do just costly. The biggest problem for me has been trying to control the excessive heat once the weather begins to warm up.
My only salvation will be the plants come out of the GH and go into the water garden about the 15th of April so the GH will be empty during the summer months.
In April we have some days in the 70's and sunny GH temps will quickly soar to 120F without proper ventilation.

Well, first off, not all of the energy that it absorbs will go to outside the cover; some of it will go into the pool. Also, losing a little bit of incoming energy isn't as important as stopping that outgoing energy from leaving. Is the pool cover PVC or PE? If it's PE, it will only reduce conduction/convection heat transfer. If it's PVC (or IR-aborbant coated PE), it will reduce radiative heat loss as well.

The bubbles do what bubbles do: they make it harder to lose heat ;) Picture yourself as heat trying to escape a pool. Now picture yourself with a single piece of plastic, the weight of the pool cover, sitting on top of you. You enter the pool cover, then pass through it, then radiate or are conducted away. Now picture trying to pass through a cover full of bubbles. You can't conduct very well through the plastic because there are such thin pieces of plastic leading between the bubbles. You can transfer your heat into the air in the bubbles, and from there on to the bubbles on the other side, but with tiny bubbles, convection doesn't occur readily, so the air has a higher R-value. When you get past a bubble, you have to go into plastic again, then into another bubble, and so on.

In short, things full of tiny air spaces are the best insulators against conductive heat loss. The best insulator, apart from a vacuum, is aerogel. It's a really neat substance made of tiny strands of glass that's almost all airspace. It's only barely heavier than air, and is strange to hold because of that. Feels like stryofoam. However, while your average styrofoam weighs ~30 kg/m^3, the lighest aerogel weighs only 1 kg/m^3. I.e., your average person wouldn't have too much trouble picking up a cube of it measuring ten feet on a side.

If only it wasn't so darned expensive, it would be a perfect inner layer for greenhouse glazing. It even scatters light (usually has a bluish tint, but clear aerogels have been produced).

When you do the maths an equally effective way to heat your pool up is to pour a cup of clear oil on the surface. Most heat loss from pools is evaporative loss.

Doesn't help with your greenhouse, I know.

Aerogel is also fragile, hard to cut and ruined by even traces of water.

I think my idea of triple glazing with heat-shrink plastic is the most affordable and inexpensive solution. I bought a 250m roll of heat shrink PVC and I attach it to window frames using silicone. The film itself has negligable R-value, but I get a really thick boundary layer instead. And almost no light transmission loss. (If PVC stops thermal IR, even better!)

Go for the thinnest film you can handle, more layers are better.

This solar pool cover won't fly off

{{gwi:304350}}

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Nathan:

Aerogel insulation, as is typically proposed (and used in skylights), is not a single piece of aerogel. Rather, it's aerogel sandwiched between hard panes of glass or plastic to protect it (because, as you mentioned, it is brittle - although surprisingly strong). There's also aerogels that have small amounts of fiberglass or plastic batting incorporated into them, making them much less fragile. As for interaction with water, you can chemically treat it to make it hydrophobic if it's going to be exposed. It's a great IR absorber, too. In a way, it's a nearly perfect insulator, except for the current price, which is going down pretty quickly.

Anyways...

PVC doesn't completely stop thermal IR, but it blocks it better than PE. That's why the Japanese pay a premium to use it instead of PE.

So shrink wrap is PVC? Good -- I was wondering where I could get some cheap PVC sheeting around here. :)

Oh, as for caulk and PE: Today, I wanted to add some more spacers between the layers of my greenhouse, which meant separating some of the current spacers that are caulked on to a PE sheet. The spacers are made of an insulation that contains two layers of bubbles, bonded together, and aluminized (I had surplus, it was fluffy, so it became spacers ;) ). Well, the caulk was so tightly bonded to the PE that was easier to tear the insulation in half than to rip the caulked insulation from the PE.

Again, it's not a perfect bond. But in my case, it holds pretty tightly. :)

I just had one of those brilliant thoughts I get from time to time and I just had to write it down somewhere so I wouldn't forget it. I hope you all do not mind but in a couple of years I can search google and find it again.

Note to me, (this is a private note just for me, everyone else just scroll down to the next post....)

Next time you cover the greenhouse with poly then also get a pool cover and sandwich it between the two layers of poly and then sell the inflation blower on ebay. You got that Chris? None of this messing about with blowers and them ducting pipes to inflate the poly. Just make a pool cover sandwich that probably has an R value of at least 16mm triple wall polycarbonate and costs a quarter of the price and is easier to fit. OK the downside is when you are in there the world is just a load of spots instead of stripes but....

I hate this place, why, oh why! could someone not have triggered this thought last October before I double polyed mine!!!!!!!!!!!!!

Grrrrrr....

:)

Anyone know about this product. It may work good in a GH
http://www.radiantbarrier.com/temptrol.htm

wantabe: Or, you could use al-foil.

Chris:

There are some problems with that.

1) More layers isn't necessarily better. They add more insulation, but they also block more light.

2) R-values are not all that you should care about. Radiative heat loss (IR) is a bigger threat, and R-values are only for conduction.

It's a balance. Your best bet is air pockets between two to three layers, with at least the inner layer being IR-absorbant, and to have any areas that don't get much sunlight being as heavily insulated as you can with opaque (preferably reflective, in my opinion) insulation.

karenrei,

I don't have a hoophouse, each wall and the roof are totally seperate segments as to R value, covering etc. stressbaby nailed it on the head on this thread

http://forums2.gardenweb.com/forums/load/strucs/msg0909104730738.html

and I am surprised that thread did not get more input. Identify areas where improvement can be made and fix them. Then look at the whole structure again and work out where the "new hole" is.
On the thread about the polystyrene sheets,

http://forums2.gardenweb.com/forums/load/strucs/msg081128491250.html

I tried to point out that adding an R3 insulation to one wall was great, bumping it up to R6 may be a waste of money because there may be another place you could put some R3.

Yes, In retrospect my south roof (and sorry to use trade names but people can look it up and understand it better) should have been Tufflite IV outer, pool cover and then Tufflite infrared on the inside. A nice sandwich and cheaper and easier to install then polycarbonate triple wall.

Yes I know polycarbonate triple wall will last longer but, it is also very expensive.

I had a standard double poly inflated south roof so I gained some insulation advantage but all of that insulation was lost by a breach of the outer layer. (see my rant on this thread)
http://forums2.gardenweb.com/forums/load/strucs/msg0409365924489.html

OK, so I know I am going to lose light on the south roof because of this sandwich but I am going to get a boost in insulation, and because of the bubble wrap sandwich I am also going to get some protection from damage. The sections would be 2ft by 8ft and if I had a breach of the outer skin then my south roof loses 1/12 of its R value not 100%.

Next, as in reducing light transmission, as you say most of the light in spring is through the south wall, so a reduction in light transmission in early spring of say 15% from the south roof is still a loss but a small loss as not much of the total is coming in that way.

""any areas that don't get much sunlight being as heavily insulated as you can with opaque (preferably reflective, in my opinion) insulation.""

North wall is solid and painted white inside (reflective). Half the north roof is solid.

Changes to my configuration next spring?

1, Shade cloth hung vertically inside about a foot from the south side to reduce the tendency of young plants to grow towards the south side but as the shade cloth is on the inside it will block light to the plants but still contribute to raising the air temperature in the greenhouse.

2, Wait until the corn and bean crop is harvested and there is snow on the ground and then set fire to my old barn to the south where the shingles that hit my greenhouse in high winds come from. (insurance company please note, that was a light hearted attempt at humour.) Umm... on second thoughts, I will insure my greenhouse! :)

I wonder if I made a mistake. I put polystyrene sheets on the North wall R-5 but I didn't like the looks of the aluminum foil with the large blue manufacture name on it
I painted it white. It looks much better but will the white paint reduce the effect of the foil.

white paint is not good. It is perfectly fine to have alfoil inside an air gap behind a false wall. It is the air gap and foil combo that is the key. The foil itself has a very good thermal conductivity, it's the very low IR emittance that makes it such a good insulator.

I think foil products are definantely a good idea. Insulation just slows down heat, but this stuff will actually block it, plus it takes up a lot less space. You can probably find it at any hardware store, but if you go online it's cheaper.

gardenerwantabe,
Included is a link to another thread where we've discussed the same thing. I think Temptrol is going to be the next big thing.

Here is a link that might be useful: GardenWeb Forum

dfw,
There seems to be some concern on the other thread that you might work for the company. LOL I don't care, I am still very interested in the produce, but, DO YOU WORK FOR THEM? lol

Cris in Iowa
Where can one buy this tufflite film. I went to their site, but it doesn't look like they sell direct so where can one get it?
Thanks
1eyedJack and the Dawg

YOU MIGHT TRY USING 2X4's AROUND 2FT LONG. THEY ARE CLEAN AND WILL HOLD DOWN THE COVER IF YOU SPREAD AROUND.

ALSO ABOUT POOL COVERS AND WATER CONSERVATION:

Las Vegas NV and Roseville CA are two cities offering $50 pool cover gov't rebates.

ASK YOUR CITY TO START PROVIDING REBATES FOR POOL COVERS TO SAVE WATER.

Only 200 pools using covers can save up to 3.5 million gallons of water every year (a city tank).

Here is a link that might be useful: Las Vegas Pool Cover $50 Rebates

Success!!! I have a way to keep my solar cover on! We just bought a 16" Intex pool. I bought an 18' solar cover so that it will be big enough to go over the sides. There are 16 upright posts on this pool. I bought sixteen 2 1/2" spring clamps, (here is a link for the ones that I bought for $1.49 a piece). I just used a spring clamp to pin down the cover to the uprights, just like you would use a clothes pin. The clamps that I used had teeth on them though. So I would recommend that you use a half round file and knock the points off so that it does not damage the cover. Since it is plastic, it files easy. It has worked GREAT!

Here is a link that might be useful: Harbor Freight - Spring Clamps