Very sorry to see the damage you have here. Could have been much worse if the the whole unit blew down. The caulking should help and you also may want to consider some tie downs connected to the gutter rails to hold the walls in place.

The price is very tempting but I don't think this would withstand the winters here in NH. Guess I will keep looking.... Best of luck with the repairs!

Gordo sorry to see you have the damage but it looks like it can be rebuilt without much work.
Seeing this makes me feel like a prophet.
When you posted the pictures of your completed GH I told my wife that Unmodified GH sitting out in the open would not survive beyond the first wind storm.
Recently another poster stated that he made no modifications to his and it was VERY sturdy. I didn't comment but thought that sure was not my opinion of the 10x12 hfgh.
I put mine in a well protected area strong wind can't get to it but even in that location I would not trust the GH as it is shipped.
I think that you lost a panel first then the wind filled the gh and blew the doors off.
Mine won't see much wind but I used silicone on the panels then used #10x1" self tapping screws with a neoprene washer and put one at the top and bottom plus one in each horizontal brace. Order extra clips for the edge. On the roof I did the above plus put screws in the four corners.
I reinforced the flimsy base and the corner posts and put metal fence posts in the corners 4 foot deep to keep it in place.
Don't know if it is possible to keep it together in the open but I think in addition to the mods that I made to the frame work if I were you I would consider putting down those screw in ground anchors and cable to the top rail.
Good luck with the modifications hope they work for you.

Gato,

Sorry to see you had so much damage.

Looking at your photos it appears that the wind may have been blowing directly against the back wall. The back wall has a lot of flex. Those horizontal braces part #31 donÂt offer much strength and that wall could move enough to cause the center studs to pull loose. Once enough wind is inside the greenhouse it will provide itÂs own means of exiting. Blowing out panels, doors etc.

Adding a stronger brace over the existing #31 or in addition to that brace will strengthen that area.You may also want to install additional panel clips and add screws to the top and bottom of each panel since your greenhouse is in an area that offers no protection from the wind.

Good Luck
Ray

I will second gardnerwantabe's suggestion of the self-tapping screws. I put one on the top and bottom of each panel in my 6X8 hfgh, and my greenhouse came through two major hurricane force winds in the last 3 months without any problems (there were big trees snapped like matchsticks within 40 feet of the greenhouse.) I hope it goes back together well, and your strengthening works! All the best, Jim

gardenerwannabe and oraylawson.

I was not happy when I found the damage, but I am not anywhere near giving up. I have studied your changes and plan on using many of them in mine.

The normal direction of the wind is against the right side wall. I think most of the sill damage was due to not having the gravel in place. That goes in today. I am not sure if one panel came off first or if the wind opened the top vent and that caused the greenhouse to blow out from the inside. Have either of you found a way to keep the top vents shut?

gato_gordo,

My vents fit very tightly in the opening making it impossible to close and latch them without a stepladder. I donÂt think mine could be opened by the wind from outside, but then again mine have been in an open position since construction so I canÂt be certain.

You could probably find a way to hold them down using bungee cord.

Ray

Like so many things on these greenhouses everyone seems to have a different experience with them.
My roof vents will lift with a slight wind less than 20 mph. Once I get the openers on the spring on it should hold it closed but until then I use a long bungee cord hook it in the hole in the vent handle and hook it under horizontal brace #30 this Will keep them tightly closed. After I posted about this I was wondering if the roof vents blew open they very well could have.
Once the wind got inside the panels would bow out and slip out from under the clips. Screws in the center will cure that.
Your big problem will be if you need parts none are available from HF they order from the factory and that takes 16 weeks.
I like you attitude hang in their man you will conquer it.
I would consider cables on the prevailing wind side or build a fence for a wind break.
Good Luck with it and keep us posted on what you do to it.

gato_gordo - I was so sorry to see your post this morning. After the effort to build one of these things, I cannot begin to imagine your frustration to have the unit blown out.

General question to all: now that this has happened, and reading that Ray purposely located his in a sheltered location, I'm wondering about where to place mine.

The original plan has been to place it in a location that regardless of season, it will be in direct sunlight. But it will also be directly in the teeth of any wind that is present.

How much sun does a greenhouse actually need in order to be effective? I have a location that is considerably more sheltered from the wind, but it is similarly sheltered from sunlight due to trees and such.

This is our first greenhouse so we are uncertain as to the necessity for "all-day" sun. The purpose of our GH is to serve as a season extender for growing vegetables. We are in the mountains an hour south of Oregon with a fairly short growing season.

Greg

I was the first one on this forum to buy the 10x12 HFGH and when i started to assemble it I posted about how poorly it was designed and how it was too flimsy to withstand high wind. I just checked to see if I could find my post and it is gone. I guess the moderators didn't like me saying unflattering things about the HFGH.
This forum could be used to help people with the construction of these but apparently you have to be careful what you say or it will be deleted.
It was my intention to warn people that they needed to modify this GH rather than have them put them up and have them destroyed by wind.
All the side wall studs attach to the base with part #47 a J hook and it hooks under a flange on a lip of the base. The base it very thin sheet metal but when you bend a lip on it then anchor at the end of the lip a very small amount of pressure will cause the lip to flex. The only thing that keeps the top of the wall studs from moving is they bolt to the top rail and the top rail is bolted to the corner posts. The corner post is to hold the whole thing together but the only thing that holds the corner post is the same flimsy J hook under the lip like the wall studs. I reinforced the corner posts made them very strong this gives the rest of the structure something to anchor too.
When the wind pushes on a wall the inward push will try to release the J hook the only thing that keeps it from going inward is the top rail bolted to the corner post and the top rails at the end will push against the opposite side.
I would advise anyone who buys one of these to locate it in a place where it will not get high winds. If that is not an option then do a lot of modifications to make it stronger. The wall post are strong enough but the poor design of how they are anchored is the problem.
Now for the good news after the modifications and placing it in a sheltered location mine had no damage after a storm went through with 80 mph winds.
After the modifications I have what would have cost $3000.00 for less than a third the price.
Bottom line is those who modify it and make it strong will enjoy years of service and be happy with it. Those who don't will lose it to a thunder storm

gardenerwantabe,

Looking at the way you reinforced the corner, it appears you used a piece of square aluminum tubing to fill out the corner, then added a slightly larger piece of aluminum on the outside? Is that correct? How was the first piece of aluminum fastened to the corner posts? Are the outer fasteners just more of the same bolts used during the assembly?

{{gwi:296576}}

greginshasta
The corner post attach the same as all the rest they use a J bracket that hooks under a lip on the base. I used aluminum angle and 11/4" square tubing to fill the gap.
I put four 1/4"bolts through the angle the base and the L bracket on the inside. Be sure to drill so that you use the bracket behind and use flat washers. The base without the bracket on the back is too flimsy to hold anything.
The cross bolts are visible in the photo. You will drill through from both directions one hole lower than the other so that they don't hit where they cross.
Everything anchors to the flimsy base lip and very little pressure will cause it to bend.
If the GH is going to sit in the open I would attach a couple of small cables to the roof rail and use screw in ground anchors. When you drive your car at 60 mph stick your arm out the window and see how much pressure is on your Arm then imagine how much pressure is on something as large as the GH during a storm. If you already have your GH built push on the back wall just a tenth what you feel when you had your arm out the window of your car and you will see the wall flex a half inch. As shipped they are flimsy it is not the lack of strength in the framing it is the way they are anchored to the base. You need to stop the lip on the base from flexing. If the bottom of the base is secured to a timber then you could weld metal between the top lip and the bottom that would stop the flex. Several ways it can be done but however you do it don't matter as long as you do something to stop that upper lip from flexing because when it gives the whole wall flexes.

oh, ok - now I understand what you have here.

The upper bolts go through the angle, the square tubing, and finally throught the corner post bracket. Then, on goes the nut and that's secured.

At the bottom, the bolts go all the way to the inside where they pass through L brackets, then washers, and finally the nut. The L brackets could then be secured to the wooden base... I like it - that's really solid.

Is that correct?

By "corner post bracket" I meant "corner post fin"

Is there any info on the packaging that indicates the original Chinese manufacturer?

Is there any info on the packaging that indicates the original Chinese manufacturer?
No and when I ask harbor freight they refused to tell me.

greginshasta Yes that is correct except the L bracket goes in the corner and bolts to the base. The bottom of the base has a lip on it and I put a 1/4x3" lag bolt through the base into the timber and I installed them every two feet plus one in each side of the corners. The reason that I put my base on the timbers instead of in the ground like the instructions say to do is that thin piece of metal would rust in short time if it was in wet soil. Way I have mine not only will they be dry but it will be easy to spray paint it when it becomes necessary.

Hi Gordo!! So sorry about the damage on your greenhouse!! I had purchased an 8 X 10 that was put up "unmodified" in the late fall last year. It seemed that a few pannels and my vent would blow off at every good gust of wind. I posted about it here and everyone said they couldn't understand why the pannels were blowing off....

I'm so proud that you are receiving some help here. I'll have to look over the past threads to get some better tips than I received last year when I posted about my same problem.

Hope all works out for you!!!!!!!!!!

gardenerwantabe- yep, I was clear on the reason to mount the GH on the P/T lumber. Makes nothing but sense. Someone posted photos of a 6x8 that they set on 2x12 lumber to provide greater headroom. I was thinking about doing the same thing because we are in snow country and this would put a bit of elevation above the ground before the snow level reaches the sides. Any thoughts on that?

Also, any chance you can post a photo of the inside corner to show how you placed the L brackets? TIA.

Greg

The L bracket that I was referring to is the one that came with your GH it fits in the inside corner. When you drill the angle you want to clamp it to the base and drill through the holes from the inside. That way the base L bracket and angle will all line up. You need the L bracket because the base is so thin that is why the manufacture put it in the kit. The framing is not that bad the problem is the base and the way the studs attach to the base.

Gardenerwantabe-I see all of your previous threads on the 10x12 HFGH. I'm pretty sure that you haven't been unflattering enough to be censored.

D.

gardenerwantabe - I see what you mean now. thanks

Greg I would not add the angle to the corner post until after you have all the post installed and the top rail bolted in place because if you bolt the corner post like I have outlined above it will be impossible to move it will be very solid and if you get it just a little bit off then the holes for the top rail will not line up.. By drilling through from the back and using the holes that are already their it should be OK but to be sure add the bracing after the framing is completed.

gardenerwantabe - I agree with your point.

We built it on the driveway so we would have a flat surface near tools and power. The debate is now on as to the permanent location to which we will move it, which have been thrown into flux due to gato's wind issues. She wants it over in the corner where it will get direct (and sometimes very hot) sun - I am proposing a location between some trees where it will have some shelter from the wind, and a bit less direct sun.

I won't install either the corner bracing, or any other enhancements such as angle aluminum across the doorway or 1/2 EMT across the mid-sections until we have the GH sitting on footings at a permanent location. Then I will add all of that to stiffen and secure the unit.

2 questions:
We are in Mount Shasta, CA which is snow country (3500' elevation) and the snow can tend to be fairly wet and heavy. We had as much as 3' accumulation in some areas of the property over the past winter during some storms. Obviously I should remove snow from the roof if it accumulates like that, but I'm thinking about establishing some structural support along the roofline - either directly beneath the ridge, or adjacent to the #30 braces that are installed in the roof. Those supports would be probably be 2x4 or 2x6 lumber, supported by wood posts down to the ground. Does this seem a good idea, or unnecessary?

In an earlier post, I raised the idea of setting the GH on top of 2x12 PT fir, so that it would sit on a footing like this: {{gwi:296577}}

I see that you set your's on 4x4 PT. My thought is to raise the GH in this manner so that when snow is on the ground, at least the first foot of snow accumulation would be against the wood foundation. I realize this means a step up and over the threshold. Any thoughts on this? Does anyone believe that this amount of wood foundation, or possibly more, would help in terms of withstanding snow accumulation? Would the additional height raise any other issues concerning the effectiveness of the GH?

Thanks,
Greg

Greg I don't think a couple feet of snow would be a problem because nearly all the weight would be on the ground. Their would be some inward pressure but the panels lay on a flat surface that would support them.
I WOULD be worried about the roof. Be careful how you remove the snow from the roof you could damage the uv coating.
Their are people here that would know better than me as to how much sunlight you will need but I think it depends on your intended use of the GH. If you will grow plants from seed then it will sit empty in the summer under the tree should not be a problem at least not where I live.
Maybe you have leaves year round most of us don't have leaves in the early spring.
I really like the GH in that picture. Yes I think their are advantages to sitting it on a PT timber my main reason was two fold. I wanted it high and dry and the wife wanted to hang some baskets in it in the winter. These are baskets that hang outside in the summer and they will be in the GH all winter. If you count the floor I will have a four tier shelf and so the top shelf will be high enough that we wanted to raise the roof a little for the hanging baskets. While some have said that the 10x12 is too tall I wanted mine taller. Different strokes for different folks.
After I laid the patio blocks on top of the sand the floor is flush with the base anyway.
Where you live I would think that your biggest problem will be cooling not heating. If you are going to use it in the summer I would put it where it got some afternoon shade. Where I live we have little sun in February and that is when we will be growing are seeds so I will need a lot of grow lights plus heat. I have my GH wired with 80 amp capacity this will allow me to use three 1500 watt heaters if I need them and in the daytime when it is warmer I can still run two heaters and have enough left for the lights.
With the insulation I don't think I will need more than two heaters but I'm preparing for the worst and hoping for the bast L.O.L.

Hey Gordo, From your Pics it looks like you are down in the San Diego/Temecula Area, or Perhaps out by Cabazon/Banning. Both Areas can have some severe winds. The Reason I am wondering is that I would like to look up the WX history to see what the winds were doing when you got the damage.

I am slowly (Very Slowly) building mine (Well ok, I am still prepping the ground with the Underground Electric and water...)

I am in the Victor Valley (Southern California High Desert), and we are right in the middle of our windy season (March - June), so I am in no rush to get it completed

Our winds here during this time Average 20 MPH in the Afternoons, with the storm winds hitting 40 often, and gusting to 65.

I am actualy very impressed with how well you greenhouse came through the winds, since it was un reinforced.

I do not have a protected area to put my greenhouse in, and the winds will be hitting the greenhouse broadside, like yours. I will be putting all the roof vents on the Lee side of the roof to try and prevent them from being opened by the wind, although They still my pull open due to the lift created by the wind blowing across the roof.

I will be using Gardenwantabe's corner reinforcements. Additionaly I will be using Rays Three Horzonal Braces, on the Front and back walls, and in the center. I also Liked his Idea of Straping the Studs with The EMT Tubing (now I just have to figure out what EMT Tubing is)

I purchased enough of Charlies Glazing Clips to Double the number of Clips, and will be using the self tapping screws on the Roof and the windward side panels. (I want to leaves some panels on the Lee Side that can be removed during the summer, because no amount of Venting will keep the green house cool in the summer here.)

Hopefully you will be able to use some of these reinforcing options when you repair the damage. I dunno if you can move the vents to the lee side at this point, but the rest of the reinforcements should be feasable.

Jim

jimmydo2,

You certainly have a good eye. The greenhouse is in Perris, about 20 miles up the 215 from Temecula. Our winds are not as bad as yours, but we certainly get some activity at times.

I knew that I would need to reinforce the greenhouse, I just expected it to stay together for a week while I figured out what to do.

I have reassembled the greeenhouse and have added oraylawson's cross bracing. I caulked all the panels into place as I think this is better than doubling the clips since it glues the entire greenhouse into one solid unit. I also purchased cable wire to reinforce the corners. I just don't know at this point whether to use the cable for internal cross-bracing (corner to corner) or to use it as guy wires from the corners to stakes in the ground.

I only get to visit the greenhouse on weekends, so I won't know if it is still standing until tomorrow.

jimmydo2

EMT tubing = conduit

Very handy material. Galvanized to resist rust, strong, and cheap !

One ten foot length of 1/2" for the center wall brace and one ten foot length of 1/2" for the base supports will be enough.

Good luck with your construction.
Ray

I would use the RIDGID conduit instead of the EMT since the EMT is 40 percent lighter than the rigid. Only a couple dollar's more for a ten foot piece.
On the inside base I used 1/8X11/2" flat aluminum because I filled the base cavity with polystyrene insulation and the round conduit would not have fit. I was going to use angle but decided it would be overkill and the flat looks much better. I like aluminum over cadmium plating because over time cadmium plating will rust. The flat pieces on the base really stopped the flexing.

Gordo,
Just out of Curiosity how many tubes of Caulk did it take?

And did you just run a bead a caulk in the frame and then place the panels over it, or did you insert the panels first and then caulk the seams?

I am a firm beleiver in Caulk, I use it for all my sheds, and people are always amazed that I do not get spiders in my sheds.

jimmydo2,

I think it took 8 tubes. Since I did this after the GH was built and I am incredibly lazy, I did not take the panels out to run a bead under them; I simply ran a bead around the edge of each panel.

I have found that drilling a 1/8" hole in all vertical supports on the outside, as measured from the bottom and the top of the panel, and putting a 12 gauge wire (galv steel) and running this in a horizonal method, curle the ends over to lock in place. This will solve the problem with the panels popping out. The wind causes a vacuum on the outside of the panel and it bowls out from the center. Then the clips take off and the panel goes sailing.

As far as getting replacement panels, the shipping alone will eat up any savings, so I waited until the 6x8 HFGH went on sale again, then bought a second unit to be used as replacement parts.