I’ve gotten the framing part down, what I’m concerned about is decking the rafters..
what I’d like to do is not use plywood.. rather have the roof decking exposed to view from below..
The only way that I can imagine to do it is have some real wide boards cut in an arch to conform to the curve. since we’re talking about bandsaw time how will I be able to hold the widths evan over the curve? I mean I can’t run it over a jointer.
I thought about bending the boards either green or with steam, yet I’m not certain that it would be possible to have a nice consistant bend with either method..
Replies
What kind of radius are you talking about?
What will work for a 100 ft radius would be much different than a 10 ft radius and different from a 1 ft radius.
Blending green boards, radius cutting on the bandsaw, and laminating from thinner slices are all possibilities.
Details?
I'm not absolutely certain.. I'll need to go to the drawing board and figure things out a bit. Off the top of my head I think a thirty foot radius is what I have in mind. However, I will work with the numbers a bit to see what looks good..
I've actually thought of using a compound cone shape to ease the fabrication.. that is I think bending green boards would be possible to keep fair and sweet if the radius is large enough and the boards are green enough (and thin enough) and as the curve increases near the top go to bandsawing out the narrower boards from much wider boards..
this is getting susiciously close to boat building so maybe that's where I need to seek help..
What kind of thickness?
Try it, but I think that that you should be able to bend most boards into a 30ft radius.
For where it gets tighter I would look at laminating thinner boards in place.
You are probably still talking about fairly large radius. Resaw them into 3/8. 1/2, 3/4" inch depending on the radius. Then nail down the first layer and then using some poly glue put the next layer on top and nail down. You don't need to perfect fair curve that you do in furniture, nor do you need the clean edges and matched grain that you get some laminating pieces sawn from a single slab and gluing back in the same order.
Now if you want to build it like a boat you need one of these bandsaws.
http://www.tannewitz.com/tannwood/prod03.asp
Bill,
won't there be gaps that show if the boards aren't "sweet" the whole way? In doing my roof in the billard room I spent a great deal of time getting the boards the exact correct width and still there was minor deviations and boards that bowed a little between the time I milled everything and they went up.
It drove me nuts especially the day the wind was blowing about 30 miles per hour from the north and the air temp was 20 below.. There I am hanging off the roof 35 feet above the ground and I'm trying to judge an 1/8th of an inch. I hung on with one hand, put the board in place with the other and with my third hand I nailed it in place..
darn boards started to drift off true and 3/4 of the way up the timbers I had to cheat one side of each board by an 1/8th.
I can see that if I try to simply bend a board around the inside will need to bend further than the outside (or top and bottom depending on how you look at it) and if I try to just nail it into place at some point it will buckle at some point and cause me grief..
Aye, ye need to larn to spile...you'll get to make your own tools! EliphIno!
What kind of shape are you puting these over? You might need to run purlions are block or something so that run an interior show sheathing in a different direction where the boards don't need to both bend and warp at the same time.
Also mill a rabbit on each edge, but opposition sides so that you have a ship lap. That will hide small gaps.
For shape my first thought was a cone.. cut in half kinda thing. the timbers that form the rafters at the top come together and spread out untill they are 24 inches apart and then I'll run a header between timbers to start up another rafter so they'll be close together again spreading out untill they reach 24 inches where I'll do another header, timber etc. that way the longest purlin possible would be 24 inches..
Meanwhile from the inside the beams will be done in a hammer beam sorta deal.
I do like your idea of ship lapping to hide gaps.. I should have done that rather than butting the boards together like I did over the billard room.. Thanks, that's a great solution..
I realize that it'd be relatively simple to run the boards vertically but I don't think that would look as nice.. Too busy with all the vertical lines. That's primarily why I want to do it horizontally. Of course if I botch the job putting the decking on horizontally That would look much worse..
How far apart are your rafters? Can you just cut shorter sections, miter the ends and just have a series of flat areas instead of curves? I think I'm going to do this on part of my deck that I am going to do like the deck in the latest issue of FHB. (Page 71), my rafters are 24" oc so the fact that the pieces are not curved shouldn't be very obvious.
Here's a picture of the porch so far. Still waiting to get the sawmill back so I can cut some more timbers
neat pics. neat house!
I especially don't want to flatten out the bow.. to me some of the magic of working with your own house is you can take the time to do things that you could never afford to have someone else do..
I'm thinking of using the rafters about 24 inches apart at the ends and of course meeting at the top..