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After some effort I managed to hand saw some fairly neat and flat miters at 22.5°. The problem is that what fits perfectly down at the ground is very different 7' in the air. The angles have changed because of the twist in the posts and small angles of post lean are greatly magnified. The orange ratchet straps were used to pull the posts upright. So that my laser rangefinder read the same distance between opposite posts at the ground and upper floor levels.
This image shows the first inner beam raised as a trial piece to discover any problems. The timber brackets are merely held with old bar clamps. I really ought to get some new and much better ones. Like many of my hand tools, my few remaining clamps were all bought secondhand.
I used ladders to provide the initial beam support while I clamped the brackets to the posts. The lift was not too difficult with just a 3m, 10' length of 2x8 to deal with.
The outer beams will be longer and heavier so I had better get the brackets properly fixed! They will have to support more than double the present weight plus the entire floor system on top of that! The notches are beginning to seem more essential than merely desirable. While construction adhesive will offer a good deal of extra insurance if I can find the right one. Bulldog toothed washers have worked well on all the joints on my shed.
I had a good look at the timber bracket options and returned to 4x4. With a slice off at 22.5° it will not project beyond the exterior octagon line. Every other option involving 2x4, 2x6 and 2x8 would require a hole in the sheathing plywood. Which would be a bad weather magnet unless carefully sealed. The 4x4 timber supports the full width of the doubled beam but not over a very large area.
With a little experimentation and reversal on the saw bed I was able to cut a 40cm or 16" length of timber to the correct angle. The trick was to clamp a scrap length of 2x8 square cut timber on both sides to stop the 4x4 from moving about during the cut. The limitation on cut length was due entirely to the DeWalt's hard, plastic, sawdust collector funnel not passing over the 4x4 when the miter saw was set to 22.5°. A 45° miter would have been even worse.
A quick plane over the sawn surface and I had my first, finished timber bracket. Next I need to notch the post to provide some more serious support. It has been emphasized by my forum experts that bolts alone are not enough. I shall use one of my routers with a jig clamped in place on the post. It is quite windy today, so the sawdust from the router will be flying everywhere!
I couldn't use the router jig because of the tie back to the shed. It would have been too much work to remove it. So I used a router freehand with a 1/2", 12mm bit to make a pocket 1/2", 12mm deep. Once full depth was a achieved I chiseled away the uncut rim which was left behind. A final smoothing with a bull-nose plane and the notch was acceptable. The bracket only fills the lower half of the notch. The doubled 2x8s will pass over it and rest on top. The bracket provides two flat, opposed surfaces parallel with each other. So safely avoids problems with clamping oblique surfaces.
I did not dare to greatly reduce the post at midway in case it weakened it. With a low deck it would have been perfectly normal practice to notch the post to the full depth of the doubled beams. With a deck there are no bending loads on the notches.
My two storey building is quite another matter. Wind loads on the top half of the building will try to flex the notched posts. Timber is apt to flex where it is weakest or thinnest. Filling the notch with a glued and bolted lump of solid timber will help to bring back some of the lost strength. Though this assumes the glue is as strong, or stronger than the wood itself.
The last image shows the first, doubled 2x8 beam resting on the oddly-shaped, [4x4] wooden brackets. The inner beam has an acute miter angle on each end. This angle fits against the notch in the upright post. The full length beam then lies alongside and overhangs beyond the octagon to provide a strong support for the planned veranda.
Once the bracket has been glued into the notch and bolted in place the beams can safely carry the floor joists above. The two, doubled beams will be screwed to each other and to the posts. The octagon of upper rim joists [seen just above the beams] will have to be moved to the tops of the posts. This will make room for the parallel floor joists resting on the beams once all flour are raised into place.
The second notch was more quickly cut out by using the router with its adjustable fence. This left a much smaller frame to be finally chiseled away. An alternative would have been to clamp battens beside the notch to set the depth of the router cut via its base plate. The router base needs support or it will go on cutting all the way through whatever it rests on. While I ended up looking like an off-white snowman with my clothes and hair plastered with thick sawdust.
Today I repeated the notching of posts and sawing timber brackets.
The outer beams will be longer and heavier so I had better get the brackets properly fixed! They will have to support more than double the present weight plus the entire floor system on top of that! The notches are beginning to seem more essential than merely desirable. While construction adhesive will offer a good deal of extra insurance if I can find the right one. Bulldog toothed washers have worked well on all the joints on my shed.
I had a good look at the timber bracket options and returned to 4x4. With a slice off at 22.5° it will not project beyond the exterior octagon line. Every other option involving 2x4, 2x6 and 2x8 would require a hole in the sheathing plywood. Which would be a bad weather magnet unless carefully sealed. The 4x4 timber supports the full width of the doubled beam but not over a very large area.With a little experimentation and reversal on the saw bed I was able to cut a 40cm or 16" length of timber to the correct angle. The trick was to clamp a scrap length of 2x8 square cut timber on both sides to stop the 4x4 from moving about during the cut. The limitation on cut length was due entirely to the DeWalt's hard, plastic, sawdust collector funnel not passing over the 4x4 when the miter saw was set to 22.5°. A 45° miter would have been even worse.
A quick plane over the sawn surface and I had my first, finished timber bracket. Next I need to notch the post to provide some more serious support. It has been emphasized by my forum experts that bolts alone are not enough. I shall use one of my routers with a jig clamped in place on the post. It is quite windy today, so the sawdust from the router will be flying everywhere!I couldn't use the router jig because of the tie back to the shed. It would have been too much work to remove it. So I used a router freehand with a 1/2", 12mm bit to make a pocket 1/2", 12mm deep. Once full depth was a achieved I chiseled away the uncut rim which was left behind. A final smoothing with a bull-nose plane and the notch was acceptable. The bracket only fills the lower half of the notch. The doubled 2x8s will pass over it and rest on top. The bracket provides two flat, opposed surfaces parallel with each other. So safely avoids problems with clamping oblique surfaces.
I did not dare to greatly reduce the post at midway in case it weakened it. With a low deck it would have been perfectly normal practice to notch the post to the full depth of the doubled beams. With a deck there are no bending loads on the notches.
My two storey building is quite another matter. Wind loads on the top half of the building will try to flex the notched posts. Timber is apt to flex where it is weakest or thinnest. Filling the notch with a glued and bolted lump of solid timber will help to bring back some of the lost strength. Though this assumes the glue is as strong, or stronger than the wood itself.
The last image shows the first, doubled 2x8 beam resting on the oddly-shaped, [4x4] wooden brackets. The inner beam has an acute miter angle on each end. This angle fits against the notch in the upright post. The full length beam then lies alongside and overhangs beyond the octagon to provide a strong support for the planned veranda.Once the bracket has been glued into the notch and bolted in place the beams can safely carry the floor joists above. The two, doubled beams will be screwed to each other and to the posts. The octagon of upper rim joists [seen just above the beams] will have to be moved to the tops of the posts. This will make room for the parallel floor joists resting on the beams once all flour are raised into place.
The second notch was more quickly cut out by using the router with its adjustable fence. This left a much smaller frame to be finally chiseled away. An alternative would have been to clamp battens beside the notch to set the depth of the router cut via its base plate. The router base needs support or it will go on cutting all the way through whatever it rests on. While I ended up looking like an off-white snowman with my clothes and hair plastered with thick sawdust.
Today I repeated the notching of posts and sawing timber brackets.
Click on any image for an enlargement.
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