- Dec 21, 2009
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https://www.backyardchickens.com/forum/viewtopic.php?id=280847
In the above thread, I built a solid foundation that is critter proof and suitable for the high winds here in the Columbia River Gorge. You have probably seen the recent video on the news that was taken at Crown Point Oregon the other day, when the sustained winds at that point were 100 MPH. We didn't get that kind of wind here, but we did have sustained winds in the 40's with gusts up as high as 60 mph. That's enough wind to ruin any kind of structure that is not anchored properly, so please review that thread to see how we got to the point we are at today.
I am installing a double beam supported roof that slants one foot to the rear. The front posts were cut off level at seven feet above the top of the foundation timbers, and the rear timbers were cut off level six feet above the top of the rear foundation timbers. The two beams are made from 12' lengths of 4x6 green Douglas Fir. It is inexpensive, and it will not rot, ever. (The East span that carries I-5 over the Columbia River at Portland, OR was built 103 years ago on top of multiple douglas fir pilings that were driven 50 feet into the bottom of the river, and they are still there today.)
I prepared the timbers by measuring the layout between the base of the 4x4 posts, and carefully drawing it out on the timber. Then I used a countersink bit to bore a 3/4" deep hole, then switched to a 3/8" auger and drilled holes nice and straight all the way through the 6" dimension of the timbers, in three spots on each timber.
Once I got the timbers into position on the posts, I dropped an 8" long by 3/8" diameter carriage bolt with a washer into each hole, and used my air impact gun to drive each bolt tightly down into the center of each 4x4 timber. You can feel the assembly solidify as the bolt draws down.
As you can probably tell, this assembly is extremely rigid. It is not overkill to use a timber that size. It fits perfectly on top of the post, and the size of it means it will never sag between the posts as a 2x4 surely would. By using a solid beam like this, it will also break up any wind that does get under the roof as you will see...
Now it is a matter of fitting the roof joists into place. i am using 8' green Douglas Fir 2x4 for roof framing. I designed and built my roof for a specific type of roofing, a corrugated foamed polycarbonate which you will see soon. I chose to frame the entire roof on 12" centers to simplify things in a number of ways down the road. The material I am using for roofing is opaque, dark green in color, very light weight, and the manufacturer offers a neat pamphlet at the Home Center that explains exactly how to install it, what other materials you need, and especially the special fasteners that you need to secure the material properly. You must choose your own roofing material, and design and build to that. My design needs to be waterproof and wind proof, and be able to support a moderate occasional snow load.
The first step is to locate, mark and cut a pair of "birdsmouths" on the 2x4 roof joists. Friction is what holds wooden buildings together, and the fasteners you use merely squeeze the parts together in order to maximize friction. If you make sure that two pieces of wood touch with the maximum amount of surface area, your joints will be very strong. (I won't describe how to make a birdsmouth, it is a carpentry skill that is explained elsewhere). I laid out and cut all of my joists to length and cut both birdsmouths in my shop on a rainy day.
I also cut a series of 10.5" 2x4 spacers to fill the gap between the joists, to provide a further attachment point to the 4x6 beams, and to provide a nailer to support the roofing down the center of the roof.
A word on assembly. I used my air nailer with 2" galvanized wire nails to do all of my assembly and to immobilize the parts, and then came back and secured everything to the main beams with 3.5" construction screws. Screws will never pull out, and you avoid bursitis in your elbows if you don't go swinging a framing hammer several million times. I use "Gold Screws" because they are stainless steel, are very strong and are very easy to drive. I buy them by the five pound box, and this project will use several different sizes.
Add a joist, screw it down, nail in the spacers, repeat.
Once all the joists were in, I added another 2x4 to the front and the back. I used a large C-clamp to help align everything, and the front cap is double-screwed into each roof joist. The front support for the roof panels will be nailed to this 2x4 so it must be rigid and well supported.
Once you have everything attached firmly with enough screws, you will be amazed at how rigid the entire structure is, and that's good because now it's time to roof it. Again, what you do now depends entirely upon what kind of roofing you have chosen and how the manufacturer recommends you install it.
My roofing started with a set of the corrugated supports air nailed in position, then each 26" sheet was progressively added and screwed into place. My screws had an EPDM rubber gasket on each one, and a quarter-inch drive bolt head; so I got a 1/4 drive socket for the power driver and used it to install the screws. They are so sharp that they drill neatly through the foamed plastic and into the roof joists. My roof turned out incredibly strong, and the winds of the past few days have proven how durable it is.
You can also see how the beam and the spacers between the joists act as a solid wind break across the entire length of the beam, and it protects the whole structure from gusts.
Looks really good, and best of all, no leaks! I'm on to building the coop now that I can work under cover with no danger of getting wet. And the whole structure is now so incredibly strong, It's very satisfying to give it a pound once in a while just to feel how solid it is...
I will shortly be putting up another post that begins to detail where I am on the McMansion itself.
Cheers!!
In the above thread, I built a solid foundation that is critter proof and suitable for the high winds here in the Columbia River Gorge. You have probably seen the recent video on the news that was taken at Crown Point Oregon the other day, when the sustained winds at that point were 100 MPH. We didn't get that kind of wind here, but we did have sustained winds in the 40's with gusts up as high as 60 mph. That's enough wind to ruin any kind of structure that is not anchored properly, so please review that thread to see how we got to the point we are at today.
I am installing a double beam supported roof that slants one foot to the rear. The front posts were cut off level at seven feet above the top of the foundation timbers, and the rear timbers were cut off level six feet above the top of the rear foundation timbers. The two beams are made from 12' lengths of 4x6 green Douglas Fir. It is inexpensive, and it will not rot, ever. (The East span that carries I-5 over the Columbia River at Portland, OR was built 103 years ago on top of multiple douglas fir pilings that were driven 50 feet into the bottom of the river, and they are still there today.)
I prepared the timbers by measuring the layout between the base of the 4x4 posts, and carefully drawing it out on the timber. Then I used a countersink bit to bore a 3/4" deep hole, then switched to a 3/8" auger and drilled holes nice and straight all the way through the 6" dimension of the timbers, in three spots on each timber.
Once I got the timbers into position on the posts, I dropped an 8" long by 3/8" diameter carriage bolt with a washer into each hole, and used my air impact gun to drive each bolt tightly down into the center of each 4x4 timber. You can feel the assembly solidify as the bolt draws down.
As you can probably tell, this assembly is extremely rigid. It is not overkill to use a timber that size. It fits perfectly on top of the post, and the size of it means it will never sag between the posts as a 2x4 surely would. By using a solid beam like this, it will also break up any wind that does get under the roof as you will see...
Now it is a matter of fitting the roof joists into place. i am using 8' green Douglas Fir 2x4 for roof framing. I designed and built my roof for a specific type of roofing, a corrugated foamed polycarbonate which you will see soon. I chose to frame the entire roof on 12" centers to simplify things in a number of ways down the road. The material I am using for roofing is opaque, dark green in color, very light weight, and the manufacturer offers a neat pamphlet at the Home Center that explains exactly how to install it, what other materials you need, and especially the special fasteners that you need to secure the material properly. You must choose your own roofing material, and design and build to that. My design needs to be waterproof and wind proof, and be able to support a moderate occasional snow load.
The first step is to locate, mark and cut a pair of "birdsmouths" on the 2x4 roof joists. Friction is what holds wooden buildings together, and the fasteners you use merely squeeze the parts together in order to maximize friction. If you make sure that two pieces of wood touch with the maximum amount of surface area, your joints will be very strong. (I won't describe how to make a birdsmouth, it is a carpentry skill that is explained elsewhere). I laid out and cut all of my joists to length and cut both birdsmouths in my shop on a rainy day.
I also cut a series of 10.5" 2x4 spacers to fill the gap between the joists, to provide a further attachment point to the 4x6 beams, and to provide a nailer to support the roofing down the center of the roof.
A word on assembly. I used my air nailer with 2" galvanized wire nails to do all of my assembly and to immobilize the parts, and then came back and secured everything to the main beams with 3.5" construction screws. Screws will never pull out, and you avoid bursitis in your elbows if you don't go swinging a framing hammer several million times. I use "Gold Screws" because they are stainless steel, are very strong and are very easy to drive. I buy them by the five pound box, and this project will use several different sizes.
Add a joist, screw it down, nail in the spacers, repeat.
Once all the joists were in, I added another 2x4 to the front and the back. I used a large C-clamp to help align everything, and the front cap is double-screwed into each roof joist. The front support for the roof panels will be nailed to this 2x4 so it must be rigid and well supported.
Once you have everything attached firmly with enough screws, you will be amazed at how rigid the entire structure is, and that's good because now it's time to roof it. Again, what you do now depends entirely upon what kind of roofing you have chosen and how the manufacturer recommends you install it.
My roofing started with a set of the corrugated supports air nailed in position, then each 26" sheet was progressively added and screwed into place. My screws had an EPDM rubber gasket on each one, and a quarter-inch drive bolt head; so I got a 1/4 drive socket for the power driver and used it to install the screws. They are so sharp that they drill neatly through the foamed plastic and into the roof joists. My roof turned out incredibly strong, and the winds of the past few days have proven how durable it is.
You can also see how the beam and the spacers between the joists act as a solid wind break across the entire length of the beam, and it protects the whole structure from gusts.
Looks really good, and best of all, no leaks! I'm on to building the coop now that I can work under cover with no danger of getting wet. And the whole structure is now so incredibly strong, It's very satisfying to give it a pound once in a while just to feel how solid it is...
I will shortly be putting up another post that begins to detail where I am on the McMansion itself.
Cheers!!
