block wall height

[steve_moran38]

building a single storey block extension and at the stage of blocking up.
Am I right in thinking the inner skin is 1 course higher than the outer skin to accommodate the the wall plate and trusses ? To achieve somewhere near 2400 mm height I'm going 11 courses inner skin (2475mm) and thinking 10 courses outer !

 

[freddiemercurystwin]

The difference between the outer & inner skin heights varies depending on the pitch and the soffit levels and the eaves detail. If necessary adjust the inner skin height with a brick course or 2 to suit.

 

[noseall]

As freddy has stated, the wall plate height will dictate the finished (internal) block level.

In most cases the external brickwork finishes a course above doors and windows, i.e. door and window height = 2100mm + 1 course.

Echoing freddies points, the soffit width and fascia depth can be adjusted by shortening or lengthening the rafter ends. It is better (in my opinion) for the soffit board to actually rest on the final course of brickwork then you can trap it down by fitting cradling attached to the rafter end, forming a solid job.

The soffit detail is an interesting part of the roof and is sometimes overlooked or feebly built.

 

[steve_moran38]

thanks freddy and noseall. So I'll build my 2 skins the same height and see what the trusses sit like on the wall plate. if required I can add an extra course of block to the inner skin. It's a 30 degree pitch, Regarding height of doorways 2100, using block I can get to 2025 so is a brick required to push up to 2100 ?

 

[freddiemercurystwin]

bricks are 65 high + 10 mortar is 75, you build up the inner skin with extra courses of brick to suit if 1 block (3 brick courses) is too much.

 

[noseall]

You will need to use lightweight coursing bricks on the inner skin.