ᐅ Span of a Cantilevered Timber Frame Ceiling

Hello everyone,

First of all: I am not looking for a structural calculation or anything like that, but rather have a question about the general construction.

I want to build a pool house in the garden, measuring 6m (20 feet) long and 4m (13 feet) wide. The construction will be timber frame. Ideally, I would like to avoid any obstructive walls or supports facing the garden side, and the roof should not rest on anything there either. Now I am wondering how I should best design or build the roof structure so that the project is practical and functional. Maybe some of you have drawings, plans, or cross-sections showing what such a construction looks like in practice. I have already searched online without much success and hope for your help.

Or do the roof beams actually only rest on the two shorter wall sections and are then connected at the front, on the cantilevered edge, by tenons or metal joist hangers?

I hope it is clear what I mean.

Example photos showing how I imagine the construction are attached.

Thank you very much.

Every carpenter would plan this for you. Or is this supposed to be a DIY project?

Yes, exactly, I am building the project myself, hence the question.

Don't you also need a plan and then a building permit / planning permission?

Have someone with expertise in structural engineering calculate that. Wind load, snow load, the dead load, and a 4 x 6 m (13 x 20 ft) sail area are no small matter, especially without a corner support. Maybe you can find a building plan online.

As mentioned at the beginning, I am not looking for a static load calculation or similar.

I have already reviewed several building instructions for various garden sheds, but unfortunately, none were constructed accordingly. Most are made of single-layer wood panels. Here, a proper timber frame structure with double-sided sheathing is being built.

What I am actually looking for is simply a drawing or sketch showing how such a roof structure can be constructed with limited bearing surface, or how it could be specifically fastened in that case. Dimensions and structural calculations are not included here.