Paddy Murphy

I just read my post from 2013. My greenhouse has been up for several years now, I think this is the third winter, the greenhouse ends still need to be redone, but the roof is in good shape and functions as it should. There is no moss growing on the roof, though after a rainstorm, some water may remain in the grooves of the sun panels, but the sun quickly dries out the panels. In Maine, we have a lot of rain, but not so much as to be a problem with moss growing. The summers are not so excessively hot as to pose a problem with melting the roof panels. During the winter, if the snow on the GH roof becomes excessively deep, I use a snow rake to remove as much of the snow as I can.

Go look at Ana White's website, http://ana-white.com/2012/05/plans/barn-greenhouse. She used gussets to create the barn style roof. She also used a 2x4 across the roof at the peak. I would have used a gusset at the peak. The corrugated panels will hold water, a place for moss to grow blocking the sunlight. I would have lined the panel ridges vertical, rather than horizontal. All in all, I like the design, somewhat similar to what I was planning. The bottom of the greenhouse is metal, I would have put T1-11 called Smart Siding, it is already painted and I think could make a tighter seal than metal. Insulate the inside of the smart siding, using rigid foam insulation. Put a heater in the GH, wood stove, the stove pipe run down the length of the GH to distribute the heat. Don't forget the building permit.

Jay C. White Cloud wrote:Hello N. McCoy,

I have some reservation about Beki Gamble's general plan, but with some "tweaking" it could work fine. I must point out some misinformation in your post.

White Pine is not use for structural support...

This is plainly not a true statement and must be corrected for the betterment of this forum's general information. I am a traditional timber wright, and can assure you that White Pine is not only a structural timber, it is one of the leading timber species used in vintage traditional timber frames, as well as, contemporary timber frames and log cabin architecture. That includes the posts, beams, and all structural timber elements, when done correctly.

white cedar, which is available locally, much stronger and is more decay resistant...

Again, other than decay resistance, this comment is not accurate in any way. I will just list a Compression Parallel to the Grain Maximum Crushing Strength in psi, then provide a link for the others structural numbers. As you can see, White Pine is 840 psi stronger than White Cedar. Cedar in generally a very weak wood.

Cedar, Northern White: 3,960

Pine, Eastern white: 4,800

http://www.woodworkweb.com/woodwork-topics/wood/146-wood-strengths.html

I have to concede, I am not an expert in these matters, but I had looked at a USDA Plant Guide site and it had said that cedar is used for log cabins and poles, I am assuming telephone poles. Felt that cedar would be a good alternative to pine. Maybe modern day timber framing uses pine, but in the old days, chestnut is used. I know it is no longer available, there are a couple chestnut trees that are maturing to their former heights, so maybe a resistant strain is evolving and we can get our chestnut trees back.

Revisiting the pine issue, pine does poorly in wet conditions, so I still have reservations on that one. I also thought creosote was an endangered species and could not be gotten, except maybe by special permit or maybe smuggled in across the border.

Thanks for correcting my errors.

beki gamble wrote:So the home we are building will have post and beams made from white pine that has been cured and had the bark and cambium removed. We are planning on submerging them in a stone foundation resting on a concrete footing with gravel back fill. the beams will go all the way to the footing. We were planning on using creosote where the beam will be touching stone or cement, because we will not be able to access it to re-treat it. We are hoping this will prevent rotting. the house is on top of a well drained hill and will have a very large overhanging roof. We are in NH, where it can get wet, cold, dry and hot depending on the month. I know creosote is gross, but I dont know what will work better. The plans have been approved by a building inspector.

My question is Will this be enough to prevent rot? Is there some fatal flaw I have overseen? Any suggestions?

thanks everybody.

I would be cautious of using white pine, it is a pretty soft wood that can go punky quite easily, just take a walk through a white pine forest. I would suggest investing in white cedar, which is available locally, much stronger and is more decay resistant. White Pine is not use for structural support. Your building inspector is not doing you any favors, it is not the right material for the use you are planning, use White Cedar instead and consult with the university extension service for selecting the proper materials.

Jose Reymondez wrote:Does anyone know of good sources for DIY Greenhouse designs that use wood?

I wasn't sure which forum to post this in so mods you can move this as you see fit.

I have been looking at PVC greenhouse for over 2 years, could not bring myself to invest $200 in plastic. I recently saw this Gothic Style PVC greenhouse out of New Mexico State University Cooperative Extension Service, I have the pdf explaining the construction methods. This is what I wanted, but not quite so big. So, after thinking aboout this, I have come up with a wood prototype for my wood greenhouse. I am using 1"x 3" furring strips, an 8 foot piece is $1.52 at Home Depot. I am cutting them with a 22.5 degree cut, two pieces joined together make the 45 degree angle, just as the pdf explains. I am making wood gussets to join each joint together using luan 5 mm plywood. The arches will be light in weight, but still strong. The arches will be spaced 2 feet apart and will join the arches together with more furring strips. The furring strips tend to be strong, but also somewhat brittle in that they easily split when screwed. Pre-drilling should solve that problem. I plan to cover the arches with vinyl sheeting which should last several years. The tie downs and the end walls yet to be contemplated. I will provide more info latter on and maybe some pics. Right now, I have designed a template for the gussets and want to start putting stuff together in the near future. I am excited to have an alternative to PVC without having a major construction project. I plan my wood hoop house to be portable, but also can be maintained very easily.

I need to add a bit more about my canning. I use an 8 quart Mirro Pressure cooker for canning. It will do 4 quart jars at one time. For doing tomatoes, the manual recommends 25 minutes at 10 lbs pressure. For 4 quart jars in the canner, add 1.5 quarts water to the canner. These instructions are only for an 8 quart canner. I found this the easiest and quickest method for canning tomatoes. To me far better than the water bath method. Less heat and steam in the kitchen during the hottest time of the year.

Steam canners are only good for high acid foods, a quick and dirty solution. I have used a pressure canner for canning high acid foods, quick and easy, the time the pressure valve jiggles is very short for high acid foods, I think about 10 minutes for canning 4 quarts in an 8 quart canner. Follow the instructions that come with the pressure cooker. I found this was the fastest way to can. Biggest problem is always making sure the pressure is maintained at the proper setting during the canning process.