Braced and ledged doors - do they settle?

[cdbe]

I'm building a wall and door at the end of my new caravan house. It will be composite cladding on a timber frame. The wonderful AI has made me a nice representation of what I want - a simple "frameless design.

My question is, will my door sag?

It will be a braced and ledged 3x2 flat frame with the cladding screwed to it, the weight will be maybe 30-40kg. Obviously if it sags even a few mm it won't look great.

Here's my previous attempt on my garden shed which I suspect may have settled a bit.

I'm just wondering if I should consider "preloading" it a bit before I clad it? Eg by hanging a bag of cement off the right hand side for a few days?

 

[JohnD]

Yes, they do. The brace cannot take any load until after the gate has sagged and pressed against it.

It is possible to construct them with a slight upward lean, so that as they settle they become approximately square.

The best way to make them is with the ledges slightly notched, so the braces fit tightly and cannot move sideways, and do not press on the stiles, which tends to open the joints. This is almost never done, I happened to see it in an old joinery apprentices manual.

On mine, I have now drilled a hole near the top and bottom of the opposite stiles, inserted a stainless tube as a liner, and fitted a ringbolt, which I can tension to lift the sagging bottom corner. This has been very successful. Use a large washer to resist twisting. I did it with ratchet straps, but am intending to fit steel studding when I get round to it, which will look better and last longer. I am in a coastal location so I mostly use stainless, but BZP would probably do if you paint it and grease the threads,

 

[opps]

off the top of my head, @GhostIntMachine is the person I would defer to.

 

[cdbe]

I'm going to build the frame a bit higher on the latch side, mount it and hang something off it to see what happens! I'm having to use parliament hinges because of the cladding and they have a bit of movement/bend in them when closed which doesn't help the situation. As the cladding is more "hung" from the frame than fixed to it I'm going to glue and screw 12mm plywood to the back of it to improve rigidity.

 

[JohnD]

The ply will also increase the weight. I don't know the load rating of parliament hinges, maybe you could use four to resist the flex?

 

[big-all]

as an aside
because you are cladding with the equivilent off i assume 300mm wide substancial cladding this will resist dropping as each panel assuming well screwed or affixed will act like a shallow brace every 300mm with the top hinge screw to bottom screw lock side acting as a shallow diagonal brace times 6