I'm planning and designing a garden shed I intend to build this fall. I've decided on a gable roof without a bottom frame, which requires a ridge beam. The ridge beam will be glued laminated timber 66x315mm, it will be self-supporting over 480cm and also a heavy roof (concrete tiles), so such a substantial dimension is required.
Anyway, I've started thinking about how to attach the roof beams to the ridge beam. Assuming that the roof beams are securely attached to the wall, it seems like they can't move downward. Therefore, I think it should be enough to attach them with an angle bracket on each side?
The alternative is joist hangers or a glued laminated support beam, but then I probably need to notch out the roof beams so that the contact surface is flat?
What do you think? Attached is a drawing I'm working on, I've marked what I mean in case it wasn't clear from the text.
I just built something similar. A sunroom 6x4.5 m with a ridge beam instead of rafters. The interior height at the ridge is nearly 3.5 m, giving the room a wonderful sense of space.
I followed your second option, i.e., glued and screwed a type of 45x70 ledger against the side of the ridge beam and notched the roof beams to fit this profile. Additionally, I installed 90x90 mm angle brackets with both anchor screws and lag screws. Finally, there's classic raw wood paneling on everything (yes, I know, this is probably complete overkill but now I know it holds well).
The biggest advantage of the ledger is that you can place the beams and complete the assembly by yourself. Much more cumbersome with "only" angle brackets.
I have a similar friggebod. My inner roof beams rest on top of the glulam beam. The outermost ones rest on the end of the glulam beam and look more like rafters. The inner roof beams are notched so they lay flat on the ridge beam. No support beams.
I have tongue and groove boards, roofing felt, and concrete tiles on.
I have a similar shed. My inner ceiling beams rest on top of the glulam beam. The outermost ones rest on the end of the glulam beam and look more like rafters. The inner ceiling joists are notched so they rest flat on the ridge beam. No ledger joists.
I have tongue and groove, tar paper, and concrete tiles on.
Yes, you can do that, but then I think you lose a bit of the point with the ridge beam. Namely, the interior ceiling height.
I'm considering joist hangers instead of a ledger joist. Should work at least as well, right? The reason is that I want the underside of the glulam beam visible and to run the interior ceiling panel all the way up to the glulam beam.
One reason I had was the possibility to insulate over the ridge beam to avoid thermal bridging. Will you be insulating?
The roof beam might be more visible in my case, but the ceiling height shouldn't be much different depending on how you handle insulation and thermal bridges. My roof rafters reach higher up to the roof peak compared to the picture, all else being equal.
The method you choose will also affect the roof pitch, which should be at least 14 degrees if you're going to have concrete tiles. The higher you can get the peaks of the roof beams, the higher you can make the walls while maintaining the roof pitch, which means higher ceiling height along the sidewalls.
So you want to nail paneling under the rafters? Then bevel the underside of the support batten at the roof angle so you have a nailing surface all the way.
One reason I had was the possibility to insulate over the ridge beam to avoid a thermal bridge. Are you going to insulate?
Yes, I plan to insulate, although I probably won't do it right away, but I am preparing for it.
The roof beam might be more visible in my case, but the ceiling height won’t make much difference depending on how you handle insulation and thermal bridges. My rafters reach the roof peak higher up compared to the picture, all else being equal.
You're right in a way, but I feel that you can't quite utilize the ceiling height in the middle if the ridge beam sticks down 315mm (in my case) right in the center. It’s hard to know how it feels/turns out without seeing it for real.
The method you choose will also affect the roof pitch which should be at least 14 degrees if you want to use concrete tiles. The higher you can get the tops of the rafters, the higher you can make the walls while maintaining the roof pitch, which means higher ceiling height along the sidewalls.
Yes, you are right. Earlier drawings had a roof pitch of 19.9 degrees and an inner measurement of 210cm at the outer walls, and 249cm up to the bottom of the ridge beam. I have now chosen some sort of middle ground between placing the beams on top (like you) and fastening them completely to the side (my previous design and also the solution in Norrbottenstorp). I am now thinking that the rafters will stick up with just half their thickness above the ridge beam. This way, the ridge beam won't be too low inside the shed, but I will also have some* room to insulate above the ridge beam (*87mm). The measurements are now 220cm at the outer walls and 240cm up to the underside of the ridge beam, and the roof pitch is now 17.0 degrees. See the picture.
Thanks for the suggestions and help, much appreciated!
So you want to nail paneling under the roof beams? Then bevel the underside of the backing battens at the roof angle so you have a nailing base all the way.
Yep, planning to cover the inside with rough cut paneling that I will paint. However, this won't happen until I insulate, whenever that will be.
Does anyone know how much raw plank, paper, battens, counter battens + ridge cap adds on top of this? The height from the outside ground to the roof ridge is now 2931.7mm on the drawing. I thus have 68mm left to build on. Doesn't seem like it's quite enough, but how extremely precise do you have to be with the roof height. It's not an exact science to determine the average ground level. And who will check the measurements?
68 mm will not be enough. The batten alone builds 50mm and the bottom edges of the ridge tiles basically rest on the roof tiles so they must also be included. I hardly think that even 15-20cm will be enough where the top of the ridge tile ends compared to the peaks of the roof rafters.
Does anyone know how much raw wood, felt, battens, and ridge tiles add on top of this? The height from the outside ground to the roof ridge is now 2931.7mm on the drawing. I thus have 68mm left to build. Doesn't feel like it's quite enough, but how extremely precise do you need to be with roof height. It's not an exact science determining the average ground level. And who will actually measure it?
Hi vectrex,
I’m building a shed with the same attachment to the ridge beam as you. Planning to notch out from the roof beam (45x170) so I can fit a 45 mm insulation piece above the ridge beam and have about a 30 mm air gap. I’ve planned a roof angle of 16 degrees, and concrete tiles.
- What height did you find the raw wood, felt, battens, and ridge tiles added for you?
I'm curious as I wish to end up just below 3 meters, but I'm having difficulty estimating where I should set the height for the ridge beam to achieve this.
Hi vectrex, I am building a friggebod with the same attachment to the ridge beam as you. I thought about notching out from the roof beam (45x170) so I can fit a 45 mm piece of insulation above the ridge beam and have about a 30 mm air gap. I have planned a roof angle of 16 degrees, and concrete tiles.
- What height did you find that the tongue and groove, felt, strapping, and battens + ridge tile add up to for you?
I'm curious as I wish to land just below 3 meters, but I'm having difficulty estimating where I should set the ridge beam height to achieve this.
Friendly greetings from Jonas
Unfortunately, I can't really answer without going out and measuring. Not particularly eager to do that right now. A reasonably educated guess is about 20cm. I know my shed is a bit too high.
Unfortunately, I can't really answer that without going out and measuring. I'm not particularly keen on that right now. A fairly qualified guess is about 20cm. I know my shed is a bit too high.
Thanks, then I'll go with 2.80 until you say otherwise. Are you afraid of the dark too? ;-)
