Wall plate dimensions

[bennettp23]

Hi,

I am trying to maximise the pitch on a single story extension. I've looked but can't find what the minimum height of a roof plate is. Default I was going with 100mm but can this be less?

170 x 45 rafters are being birdsmouthed onto it. Extension is 4m out by 7m wide.

Any help would be appreciated .

Thanks.

 

[noseall]

Are you talking about the wall plate proper - i.e. the one that is bedded on top of the block-work?

If so, it needs to be a minimum of 50mm deep (trusses) really. Proprietary tanolised wall plate is 75mm deep and is better suited for a cut roof.

 

[bennettp23]

Are you talking about the wall plate proper - i.e. the one that is bedded on top of the block-work?

If so, it needs to be a minimum of 50mm deep (trusses) really. Proprietary tanolised wall plate is 75mm deep and is better suited for a cut roof.

yes that’s the one

do you mean deep as in width or height? I’m querying height - want to to be as low as possible.

 

[catlad]

If you are going to dive in a swimming pool and someone says its only 3' deep don't do it! they don't mean its 3' wide!

 

[bennettp23]

If you are going to dive in a swimming pool and someone says its only 3' deep don't do it! they don't mean its 3' wide!

Haha fair nuff. Thanks catlad.

 

[^woody^]

25mm plate

Lower the wall

Notch the rafters

 

[bennettp23]

25mm plate

Lower the wall

Notch the rafters

Thanks Woody.

Rafters will be birdmouthed.
Don't really want to lower the wall as it has bifolds and don't really want to lose the height.
25mm - doesn't sound like there are any regs around the depth of the wall plate so will have to think about what is acceptable.

 

[^woody^]

Lowering the wall to fit a deeper plate makes no difference to the lintel height.

Why can't you raise the other end of rafters?

 

[bennettp23]

Window sills mate limit rafters placement.

lowering wall does effect lintel when I already as low as I can go to the lintel (200mm height 3300mm long). Can’t find a 90 cavity lintel that is lower than that.

 

[noseall]

25mm plate