How long a wall before a pier or return is needed.

[browfish]

I am building my exentions and have built the 2 corners up.
the extension is 14m long and 2m deep. Currently each end is 5m long with a 2m return strapped to the existing house. There is a 4m gap beteen the 2 corners waiting for the lintel for the bifold doors.
Question is, I can physically sway the walls where they are at the open end. I guess once the lintel is on and once the weight of the roof is on, this would stabilise the wall however should i have a return nib if so what is the maximum distance. there are a could of locations i could build these where i had intended to build light weight partitions.

 

[joe-90]

Take a look at your plans.

 

[tony1851]

For single-storey, you would be looking at 9m max. beween return walls or piers. Also, to keep in line with Approved Document A, your opening should be limited to 3m max.
However, once the roof is on, that will give the 2 rear walls some stability,
though not a great amount as the load from such a short width of roof will not be that much.
You could enhance rigidity in 2 ways; 1. add additional tie-down straps between the wallplate and the wall; 2. consider diaphragming the roof with plywood or OSB. This helps to make it a rigid plate. If it is then strapped securely to your walls, (rear wall and return walls) you will considerably improve overall stability.

 

[^woody^]

The need for a return pier is governed by the loads and bracing.

Walls can be fine with no returns

Document A is a basic guide and alternatives can be proven to work if need be

 

[browfish]

Why would an opening be limited to 3m? My doors going in are 4m wide and i have seen much larger.

The total length of the wall inc opening is 4m so i will put atleast one return nib in and probably 2 to be safe.

Thanks

 

[^woody^]

Why would you want to build random nibs, "to be safe"?

How do you know that they will be actually doing anything?

 

[tony1851]

Why would an opening be limited to 3m? My doors going in are 4m wide and i have seen much larger.

The total length of the wall inc opening is 4m

Sorry, I must have missed something there. I thought your opening was 4m, in a 14m long wall.

The 3m thing is only a 'deemed to satisfy' provision in the regs. You can go wider, its just that over this width, you may need to prove its OK.

 

[browfish]

I need to build 2 partitions coming off the wall, but i can do this out of block work if necessary so they wouldnt be random nibs. Obviously any wall running at right angles to the main wall is going to add lateral strength.

My building inspector is happy with the opening based on the beam i have used and the small load it is taking. He hasnt commented on the need for lateral support, that was just my concernt when laying bricks 2.4m high yesterday, i could wobble the wall with my hands.

 

[^woody^]

A roof tends to hold a wall to stop it wobbling, and the partition walls don't do much in a situation like this one

You first said you might put one or two return nibs in, and now you say you can build blockwork walls.

You can only put blockwork in if you have a foundation for the walls or a thickened slab

Really, you should be working to a plan and not thinking about this as you build it

 

[browfish]

I figured the roof would stabilise it.

Not a problem when i dont have a slab yet.

 

[^woody^]

I'd leave it then, and the roof will restrain it

 

[maltaron]

You say "when laying bricks 2.4m high yesterday, i could wobble the wall with my hands"

So the wall wobbled while the mortar was still green, what did you expect?

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