How to build a gate frame?

Question

Hi everyone!

Long time lurker, first time poster. I am looking at building a gate and frame across my driveway opening - approx 4500mm (2250mm-ish per gate frame). Wanting to build double gate frames, with spring-loaded castors, 1200mm-ish pickets.

Will 70x35mm structural treated pine be sufficient for the frame?

I have previously built a gate using 90x45s which seemed a bit overkill - see image.

Thank you 😊😊

Noyade · Answer

A guy across the road (qualified builder) from me has a 5 metre gate that swings from one steel post. Light steel frame with colourbond sheeting - no jockey wheel.

Just an afternoon thought - and I can upload a photo if interested. Cheers!

Nailbag · Answer

Hi @Kat079

Firstly well done on an awesome looking return fence and gate.

For that sized opening you will definitely need to use a steel frame ands potentially the gate casters. But I don't think you will be able to obtain the frame off-the-shelf. If you use the Fortress calculator, the wider you go the shorter the gate height. For a width of 2250mm there is no suitable height. So, you will need to look to get one custom made. Obviously then you will need very substantial support posts which, again I would recommend steel so there is no chance they will bend over time.

Nailbag

Dave-1 · Answer

Good Evening @Kat079

Thats a solid looking gate you have built. It looks pretty nice :) I will keep in mind the design for my side gate I need to replace.

Two gates spanning 4.5m I think will put the build into another class all together. Id go for the metal frame that @EricL has mentioned. Mostly because the timber + weight + covering will be a lot of weight for a post and hinges to carry. The spring loaded wheel is definitely something I would design in for both gates to help support the weight even if its a metal frame with timber slats on it like your side gate.

Can you get away with narrowing the width of the gates to bring it into the realm of less weight to carry? Maybe extend a short fence from the wall or outside fence to the first post? The more I consider the problems for a gate of 4.5m (2.25m each) I would head towards a steel frame for them.

Dave