Dovecot roof joints

skronk · 13 Oct 2014

Hi all,

Building this is no problem, but what is the finish between the 6 roof angles / joints.
How is it achieved ?

skronk · 13 Oct 2014

Been thinking.

A V shaped groove routed on the straight piece between the roof angles, allowing the straight piece to be folded at the same angle as the roof joint ??????????

Eric The Viking · 16 Oct 2014

I did an octagonal roof a couple of years ago for my mum's bird table (one of those projects that got out of hand!).

It's a similar problem so I ended up with a spreadsheet to work out the sizes and angles. You could put in the height and base "circumference" of the roof and the spreadsheet gave you the bevel angles. I was butt-joining the roof though, without any cappings.

If you have Excel and you PM me with an email address I'll see if I can dig it out. It's easily altered for a hexagonal pyramid instead of an octagonal one.

I think they've cheated by using a moulding to hide the cut ends of the lapped boards. That design will leak in a downpour though, as driving rain can get under the cappings.

Honestly, I'd use some offcuts of code 4 lead sheet to do the cappings You can weld it at the top where they all meet, and fold it back under and pin at the bottom. It should dress nicely to both slopes with something like two wallpaper seam rollers used together running along the ridge line. For mum's birdtable I couldn't find a finial (it's a lot smaller than a dovecot), so I made a lead rosette, dressed down onto the apex, and used an old brass doorhandle for the finial. If you knew what it was it looked odd, but otherwise I think I got away with it.

E.

skronk · 16 Oct 2014

Nice birdhouse Eric.

I have a printout from the net giving compund cut angles, and have indeed build a roof using them. I was curious as to how commercial ones with a strip covering each joint was achieved.

I think my idea in 2nd post is the way to go ?

Thanks for your input.

Eric The Viking · 16 Oct 2014

skronk":5lo2khhh said:
Nice birdhouse Eric.

Thanks, but it looks better than it turned out to be. I used a two-part polyurethane varnish, but it failed and the lid is now ruined after a wet winter. I'll re-make it in hardwood this time. Happily I allowed for running repairs - the centre is just 1" dowel with a stainless thread glued into the end so I can make a new roof to drop on top with minimal fuss. She says she's not bothered, but I'm embarrassed!

I have a printout from the net giving compund cut angles, and have indeed build a roof using them. I was curious as to how commercial ones with a strip covering each joint was achieved.

I couldn't work it out from the picture - is it a covering strip, or a single piece of bevelled stock (inside and outside), with grooves cut to take the boards? If it's grooved it would be quite awkward to make without a jig. Normally you might do it with a slotter on either a router table or a spindle moulder, but the angle would make it hard as you probably wouldn't get away with just featherboards.

I'm sure doves are waterproof, incidentally, so leaks probably aren't a big nuisance to them, although they might warp the boards.